In the construction of DEM, terrain features (e.g. valleys or stream lines, ridges, peaks, saddle points) are important for improving DEM accuracy and saw many applications in hydrology, precision agriculture, military trajectory planning, etc. HASM (High Accuracy Surface Modeling) is a method for surface modeling, which is based on the theory of surface. Presently, HASM is only used for scattered point's interpolation. So the work in this paper attempts to construct DEM based on the characteristic terrain information as stream lines and scattered points by HASM method. The course is described as the following steps. Firstly TIN (Triangulated Irregular Network) from the scattered points is generated. Secondly, each segment of the stream lines is well oriented to represent stream lines' flow direction, and a tree data structure (that has parent, children and brothers) is used to represent the whole stream lines' segments. A segment is a curve which does not intersect with other segments. A Water Course Flow (WCF) line is a set of segment lines connected piecewise but without overlapping or repetition, from the most upper reaches to the most lower reaches. From the stream lines' tree data structure, all the possible WCF lines are enumerated, and the start point and end point of each WCF lines is predicted from searching among the TIN. Thirdly, given a cell size, a 2-D matrix for the research region is built, and the values of the cells who were traversed by the stream lines by linear interpolation among each WCF lines. Fourthly, all the valued cells that were passed through by the stream line and that were from the scattered points are gathered as known scattered sampling points, and then HASM is used to construct the final DEM. A case study on the typical landform of plateau of China, KongTong gully of Dongzhi Plateau, Qingyang, Gausu province, is presented. The original data is manually vecterized from scanned maps 1:10,000, includes scattered points, stream lines, contour lines, precipitous cliff lines of a region of area about 4×5 square km. For simplicity only the former two kinds of data sources are used. By Comparing with the result from stream-line-constrained TIN and hydrologically correct DEM construction method Thin plate Spline (TPS, that is implemented as command TopoToRaster in ArcGIS 9.0 and later version)through visual inspection, HASM gets a more desirable DEM and more reasonable integration of information of the terrain features. Finally, some challenges and future research about HASM is also given.

The long time series of passive microwave satellite data (SMMR, SSM/I and AMSR-E) have provided important information about the earth surface science and climate research in the past three decades. Due to the update of satellite-based radiometers and their platforms, some systematic parameters are different, and there are biases among brightness temperature in different periods, which lead to inaccuracy of some parameters' retrieval. In order to obtain consistent brightness temperature datasets, and provide convenience for the researchers using these data, it is necessary to calibrate the brightness temperature from different sensors. Considering the difference between the variance of brightness temperature from different sensors on cold and warm region at the cross time, this paper analyzed the brightness temperature on the cold and warm region respectively. On the cold region, because the diurnal temperature variation is very small, the influence on brightness temperature caused by difference of the satellites overpass time during the overlap period can be ignored. The brightness temperature data at 18GHz and 37GHz channels of Nimbus-7 and 19GHz, 37GHz channels of DMSP on the Antarctic or the Greenland glacier during the overlap period were analyzed. On the warm region, due to the reason that the daily variance of temperature contributes a lot to the difference of brightness temperature from different sensors during the overlap period, the diurnal cycle of surface temperature on the Sahara desert region was analyzed, and base on it, the influence of temperature to brightness temperature was eliminated. Finally, considering the two regions, the cross coefficients of calibration were estimated.

How to project remote sensing data on a surface determines the accuracy of the remote sensing data analysis results. The dramatically increasing large scope of high resolution remote sensing imagery requires an effective data structure. In recent years, a number of data structures for global geo-referenced data sets have been proposed based on regular, multiresolution partitions of polyhedron, named as geodesic Discrete Global Grids (DGGs). The DGGs can be used to manage global multi-resolution geospatial data effectively. Octahedral quaternary triangular mesh (O-QTM) is a common discrete global grid. An effective method for analysis of remote sensing data is proposed in this paper. The remote sensing data are transformed to image based on octahedral quaternary triangular mesh. Image overlay analysis is accomplished.

Representing RS (remote sensing) images under multi-resolution is a key component of "Digital Earth", and becomes one of the fundamental problems in Geography and Spatial Information Science. QTM (Quaternary Triangular Mesh) with excellent features of global continuity, stability, hierarchy, and uniformity has the potential ability to represent the global model. In this paper, we present a method of displaying the RS images. This method is primarily divided into two steps. First, the calculated geographical coordinate of each pixel in a dataset is transformed into a QTM code at a proper subdivision level, and the pixel value is also mapped into a triangular cell which is correlative to the pixel. Second, all the triangular cells are displayed by the use of OpenGL. The transformation from geographical coordinates to QTM codes are also examined at different subdivision levels. In the end, the experiment is performed with FengYun(FY-3) Satellite Data(HDF5 format) and aerial remote images (Tif format) of Shanghai in China. The results illustrate that this method is acceptable.

With the purpose of analyzing the technique of image matching based on self-correlation, the semi-variance function from geo-statistics was introduced into the image matching of this paper, which develops a method of image matching with semi-variance function as the basis, studies the matching cell of semi-variance function image matching, constructs the semi-variance function image matching similarity measure. In addition, several image matching algorithms by semivariance function were designed and realized. By experiments of comparing with the correlation coefficient matching algorithm, it has been shown that the semi-variance function matching algorithm not only can maintain a good matching accuracy, but also greatly enhance the matching efficiency; all of these evidences reveal that the matching method based on semi-variance function is feasible one. The experiments also show that the neighboring matching algorithm is of the best effect among several matching strategies.

Recently vehicle-borne laser scanning system equipped with linear array laser scanner, GPS and INS has played an important role on the acquisition of urban spatial data. In this paper, a method was proposed for the segmentation of building facades from vehicle-borne laser scanning data in the outdoor urban environment, which contains five steps including 1) preliminary filtering with depth histogram analysis; 2) binarization of point cloud; 3) mathematical morphology processing of binary image; 4) segmentation of binary image and 5) extracting building façades with the mapping relationships of vehicle-borne laser scanning data and binary image. Depth histogram analysis, calculation of grid size and determination of the number of dilation were described in detail. Finally, an experimental study was made to demonstrate the feasibility of the proposed method for the segmentation of urban building facades.

On the basis of detailed analysis of several classic topographic correction methods, the authors proposed a new semi-empirical method according to the theories of SCS, C and Minnaert correction, which accounts for diffuse irradiance from C correction and the non-Lambertian reflectance behavior of a surface from Minnaert correction. In addition, it has the advantages of SCS method which preserves the geotropic nature of trees (vertical growth) regardless of terrain, view, and illumination angles. The new method was tested by ETM imagery acquired on April 30th, 2000 of Miyun county of Beijing, China. We analyzed comparatively the correction results through visual analysis of corrected images, statistical analysis of mean and standard deviation, and the correlation analysis between radiance and the illumination angle. The results show that the correlation between the illumination angle and radiance corrected by the new method decreases obviously and its spectral characteristics are preserved perfectly. It was concluded that the new method could be considered as a good method for topographic correction of optical remote sensing imagery in rugged terrain.

Topographic effects and atmospheric effects are two main obstacles to further application of satellite imagery. In this paper, a new method has been developed in order to extract the surface reflectance over mountainous terrain. Three diffuse subcomponents are used to approximate the solar diffuse irradiance: circumsolar, horizon brightening, and isotropic diffuse flux. Topographic adjacency irradiance is calculated using a fit model. A digital elevation model is used to obtain information about surface elevation, slope, and orientation. And the atmospheric parameters such as water vapor content, aerosol optical depth are retrieved from MODIS data. Taking the rugged area in the southern section of Gao-Li-Gong Mountain for test, the result shows that the method has robust topographic and atmospheric correction ability.

Image classification is an important technique in the digital earth. This paper gives a comprehensive study on a new proposed tolerant rough set classification method. Its essence lies in introducing the idea of k-nearest neighbors into the construction of rough set. Experiment is carried out with Landsat-5 TM image of eastern Beijing. Classification result is analyzed in detail and compared with that of the current tolerant rough set method. Outcome indicates that the method is more interpretable and reliable, and is good at handling uncertainty in the process of satellite remote sensing data classification. Also it is a promising tool at classifying areas with complex spectral feature distribution.

On the basis of the study on the enhancement methods of remote sensing images obtained after several earthquakes, the paper designed a new and optimized image enhancement model which was implemented by combining different single methods. The patterns of elementary model units and combined types of model were defined. Based on the enhancement model database, the algorithm of combinatorial model was brought out via C++ programming. The combined model was tested by processing the aerial remote sensing images obtained after 1976 Tangshan earthquake. It was proved that the definition and implementation of combined enhancement model can efficiently improve the ability and flexibility of image enhancement algorithm.

For ocean observation, the wind velocity over water is one major concern. Spaceborne microwave scatterometers can provide global, all-day, all-time, high-accuracy, high-resolution and short cycle wind velocity observations over the earth's bodies of water. For a microwave scatterometer system, backscattering coefficient accuracy and spatial resolution are two important parameters. And they are used to evaluate the performance of a scatterometer. High quality scatterometer data intends to have both high accuracy measurement of backscattering coefficient and high resolution. However, these two important parameters are restricted by each other, and cannot reach optimal level at the same time. Therefore, a compromise between the two variables is necessary for the system design of a scatterometer. In this paper, simulation results of conically scanned pencil beam scatterometers are presented. Analysis of backscattering coefficient measurement accuracy under different spatial resolution conditions is also presented. With the same instrument parameters, larger spatial resolution will increase the number of independent samples of backscattering measurement. It is well known that the backscattering coefficient accuracy of scatterometers is decided by the SNR of returned signal and number of independent samples. And simulation results show that the number of independent samples plays a more important role in backscattering coefficient accuracy than SNR of the returned signal. As a result, backscattering measurement accuracy and accuracy of retrieved wind velocity can be improved. The simulation results and analysis can be of benefit to the system design of next generation spaceborne pencil beam scatterometers.

In the past two decades, the object characteristics at L- and C-band backscattering coefficient have been widely studied, but little attention was paid to S-band, due to the main spaceborne SAR sensors are designed at L- and C-band by now. HJ-1C is planned to be launched at the end of 2009, on which an S-Band SAR is loaded. For the applications of S-band SAR, it is necessary to obtain backscattering coefficient and analysis object characteristics at this band. In this paper, S-band relation models are preliminarily analysed for several typical ground objects, using measurements obtained by the scatterometer system of University of Electronic Science and Technology of China (UESTC). Result shows the S-band scatterometer system is instable in some cases, but object characteristics can be revealed qualitative. Therefore, some improvements shall be done to advance scatterometer's performance and field-work methods when more measurements were taken. For the quantitative analysis of S-band measurements, observations from SMEX02 PALS instrument are used to compare with the theorical simulation from water-cloud model, the result shows good.

Among totally 242 spectral bands ranging from 400 to 2500 nm of Hyperion hyperspectral remote sensing data, it was found that two bands with reflectance of 1215 and 2133 nm had relatively good correlation with sediment grain-size parameters of mean diameter(Mz), skewness(Sk), medium diameter(Md) and sorting coefficient(So). And further more, the combination of band reflectance had a significant linear correlation with Mz, So, Sk and Md. Then linear regression models were established and applied to get spatial distribution characteristics of grain-size parameters at intertidal flat near the Sheyang River Estuary in Jiangsu Province. Verification by independent samples showed that the mean relative precision and the mean absolute precision exceeded 75.70% and 72.17%, respectively. Spatial distribution pattern of grain-size parameters indicated that in the direction from north to south that parallel to the coastal line, grain diameters became finer, sorting characteristics became worse and skewness moved from near symmetry to positive deviation. While at the direction from the land phase to the sea that perpendicular to coastal line, grain diameters changed coarser, sorting characteristics became better and skewness moved from positive to near symmetry. These variation trends were in accordance with hydrodynamic environments and sediments sources well.

Sediment type was one of the most important parameters of intertidal zone. The hydrodynamics and morphological changes could be indicated by sediment types very well, and the understanding of their distribution and stability could provide an important insight into littoral marine ecology. The way of conventional survey for sediment types was expensive and time-consuming. The objective of this study was to develop a method to distinguish sediment types using remote sensing, and enable which to be an alternative to traditional methods. Intertidal zone sediments were sampled at the south of Dafeng port, Yancheng city, Jiangsu province, China. Samples were collected from the upper 3cm surface of intertidal zone. The laboratory spectral reflectance data were obtained using a spectrometer. Particle-size of sediment samples were measured by Mastersizer 2000. Through analyzing characteristics of spectral reflectance for sediment samples, we found that two bands were sensitive to content of sediment components (sand, silt and clay) with central wavelengths at 864 and 1034 nm. However, the position of sensitive bands changed as moisture varied. In order to eliminate the impact of moisture on sediment spectral reflectance, moisture was introduced as a crucial factor to build regression equations with reflectance of sensitive bands to get contents of different sediment components, and then Shepard classification system was applied to acquire spatial distribution of sediment types. This way provided a quick, non-destructive and nonpolluting survey method. Meanwhile, this intelligent way of extracting information from muddy coastal zone will contribute to constructing digital earth, the huge system which benefits human beings.

Radar altimeter can map the global geoid with high precision. This paper presents a new concept of mutibeam delay/Doppler radar altimeter which combines a liner array of nadir receivers and a nadir transmitter. The delay/Doppler technology is applied in the along track, and the array signal processing technology in the cross track. The key innovation in this concept is that fan-beams form in both along track and across track, and range correction is applied in across track as in along track, so that it could provide high precision with wide swath. But the 3D-matrix store and processing of the raw data from receivers are much more complicated than a conventional radar altimeter and a delay/Doppler radar altimeter. The scheme is of obvious advantages. It could provide height profile with high precision for left scene and right scene, respectively, and leave small footprints at as far range as at near range. It could also lead to uniform cross section in each resolution cell.

The glacier is an important factor in climatologic and hydrological investigations, especially in western China. Remote sensing plays an important role for glacier inventorying and monitoring work. SAR systems have an ability to observe the earth's surface, independent of cloud conditions. Particularly, the interferometry and polarization SAR provide a useful tool for glacier investigation, such as extraction of glacial border, measurement of glacier movement and so on. In this paper, we demonstrate the methods and results for the glacier identification integrated intensity of backscattering from Envisat/ASAR images, coherence coefficients of repeat pass interferometry from ASAR and PALSAR, and full polarimetric SAR from PALSAR₀ The movements of several types of glaciers were retrievaled using the SAR interferometry, such as continental glacier, sub-continental glacier and maritime glacier.

In recent years, the method of Corner Reflectors Differential Interferometric Synthetic Aperture Radar (CRDInSAR) was proposed for overcoming the limitations of decorrelations of the conventional differential interferometric synthetic aperture radar (DInSAR) technique. In general, the corner reflector has very high RCS (Radar Cross Section) for a small size, and the maximum RCS occurs when it points directly along the boresight of the SAR antenna. The beam width of a trihedral corner reflector is rather broad (having a 3dB beam width of 40° in both elevation and azimuth), so it is fairly tolerant to installation errors. It can be made available as artificial PS (Permanent Scatterers) points by installing them on a study area due to the stable amplitude and phase performance. However, some errors of CRDInSAR system will still affect the results of measurement. In this paper, the factors influence the accuracy of CRDInSAR are discussed, which include the errors of baseline and its angle, look angle and height of corner reflector respectively.

Persistent Scatterer Interferometry (PSI) has been wildly applied to subsidence monitoring over a long temporal scale, which overcomes the problems caused by temporal and geometric decorrelations and the atmospheric dishomogeneities in conventional DInSAR by only considering the coherent pixels on temporal scale. Recently, only ascending or descending SAR data are used in most of PSI works, which is often subject to absence of SAR data in some years, continuous subsidence monitoring is not available. In this study, to realize the continuously deformation monitoring, both ascending and descending ENVISAT ASAR acquisitions of Suzhou city from 2003-2007 are taken into account. To process the two data sets at the same time, a modified linear deformation model is introduced into Coherent Target DInSAR (CT-DInSAR) technique. The result obtained in this paper suggested that by using ascending and descending orbit SAR data, more SAR acquisitions can be used in SBAS technique and continuous deformation monitoring can be operational.

Interferometric SAR is an emerging earth observation technique, especially useful in cartography and surface subsidence survey, Differential SAR Interferometry (DInSAR) provides an alternative and complementary method to investigate the land subsidence phenomena, which can provide two dimensional deformations on the line of sight (LOS) of radar on areas of thousands square kilometers. In order to obtain accurate surface subsidence, precise orbit must be provided so as to compensate the reference surface phase and topographic phase. This paper proposed a new method for SAR interferometric baseline rectification specifically for SAR satellites those have no precise orbits. The method based on the imaging geometry of interferometric SAR, during the processing we setup a coordinate system called RXA, where R is a vector directing from the scene center to the corresponding position on the orbit, A is the vector of satellite velocity, X is normal to both R and A to construct a right hand coordinate system. There are two steps in our baseline rectification process, which are perpendicular baseline rectification and parallel baseline rectification, and the singular value of phase frequency was removed by the DIA method. In our study two InSAR pairs are processed, the results show the new proposed method could compensate not only the linear part of the orbit error but also nonlinear part of the orbit error.

The 2009 Ms 7.3 Yutian Earthquake ruptured the boundary between Yutian Country and Qira Country, Xinjiang. To simulate coseismic deformation of an earthquake, usually dislocation model with the assumption of homogeneous, isotropic and elastic half-space are applied. However, these assumptions are oversimplified and not always able to precisely approximate every earthquake. Here we took Finite Element Method (FEM) instead of dislocation model to infer coseismic fault slip from surface deformation observed by InSAR. To obtain Yutian earthquake coseismic displacement, ENVISAR/ASAR data from both descending and ascending orbits were processed. AQAQUS code was taken to generate Green functions and Quadratic Programming algorithm was implemented in the linear inversion. The inversed slip distribution imply Yutian earthquake to be a simple event with only one slip concentration on the fault plane. Maximum slip is up to 3.89m near the surface, occurs at N35.370, E81.510. The estimated moment magnitude is Mw 7.1.

This paper points out that many countries are developing high-resolution SAR technique, and it also introduces the development process of object-oriented image analysis, its merits and shortcomings. After analyzing the overall process of the object-oriented remote sensing image analysis, this paper uses this method to analyze high-resolution SAR images. In the same time, it also used the traditional method of pixel-based remote sensing image analysis to analyze the images, to compare with the object-oriented method. By comparison, we can find that object-oriented remote sensing image analysis method is better. Finally, this paper forecasts the application of object-oriented remote sensing image analysis to high-resolution images.

The objective of this research is to evaluate the performance of multitemporal RADARSAT-2 polarimetric SAR data for urban land use/land-cover classification. Three dates of RADARSAT-2 polarimetric SAR data were acquired during the summer of 2008 over the rural-urban fringe of the Greater Toronto Area. The major land-cover types are residential areas, industry areas, bare land, golf courses, forest, and agricultural crops. The methodology used in this study follow the manner that first extracting the features and then carrying out the supervised classification taking the different feature combinations as an input. Support vectors machine is selected to be the classifier. SAR features including amplitude, intensity, long-term coherence, Freeman-Durden decomposition are extracted and compared by evaluating the classification abilities. Long-term coherence plays an important role in building discrimination in this study. The best classification results achieved by using the three dates HH, VH, HV amplitude layers and the coherence map. The overall accuracy is 82.3%. The results indicate that RADARSAT-2 polarimetric data has a potential to urban land-cover classification with the proper feature combinations.

A vessel detection method based on gravity enhancement was applied to Synthetic Aperture Radar (SAR) images. With the method, targets' pixels were enhanced by the interactions between themselves and their neighbors, while the speckle and background clutter were suppressed after enhancement as well as the contrasts between targets and clutter had been greatly increased. Then vessels were detected with the improved K-CFAR detector. East China Sea, off the east coast of Shanghai, China, was chosen as the experiment region. Fine resolution mode and scanSAR mode ALOS PALSAR data were utilized to validate the method. Experiment results show the method proposed in this paper have good ability for vessel detection in SAR image.

Mountain glaciers are especially sensitive to climate variations. Monitoring temperate glacier activity has become more and more necessary for economical and security reasons and as an indicator of the local effects of global climate. Glacier flow velocity plays an important role in climate monitoring and casualty forecasting, however, available velocity data is hitherto not abundant. The most studied variable in ice dynamics in the literature is ice velocity. From remotely sensed images, mainly two types of methods have been used for the estimation of glacier flow velocities: feature tracking and differential interferometric synthetic aperture radar (DInSAR). In this paper velocities of the Keqikaer glacier are acquired from ALOS (Advanced Land Observing Satellite) SAR data with feature tracking. The results show that different window size in correlation calculation of feature tracking leads to different flow field. We developed a new method to determine the best window size, and the method is testified by using SAR data.

Mountain glacier border information is one of the important parameters in detecting glacier changes. One of the major limitations of InSAR applications is decorrelation, arising from spatial baselines of interferometric pairs, time interval of SAR image acquisitions, topographic effects, and noise sources. When the temporal baseline of InSAR pairs is long (such as 35 days and 92 days), the backscattering characteristic changes fast and the coherence of glacier surface will be completely decorrelation. We use the decorrelation due to the glacier surface slope and fast moving as a valuable information to derive the mountain glaciers border. And then an application of one new methodology in Donkemadi glacier (33.08N,92.09E) in Qinghai-Tibetan Plateau is presented using the C-band ASAR data and L-band ALOS/PALSAR data. The result showed that the glacier identification accuracy better than 89% can be obtained considering TM imagery as the ground truth.

At this paper, from high resolution airborne E-SAR PolinSAR data and its statistical characteristics, Urban area land cover unsupervised classification method using polarimetric, coherence and interferometric phase differentials was proposed, and what is the role of interferometric phase differential for identification and classification of the target with vertical structure was investigated; and the potential and validation of PolinSAR data for urban area land cover identification and classification was demonstrated. The preliminary result indicates that the good classification result has been obtained, and the inclusion of interferometric phase differential significantly improved the building or man-made target identification and classification.

Human being has experienced five stages on the mountainous study, in which the form of mountain information presented like a cycle, i.e. starts from data, and changed to information, knowledge, finally returned back to data. Similarly, attribute of mountain information also experienced a cycle of objective information-subjective information-objective information. There is no essential difference between e-mountains and digital mountains. Based on the analyzing of the progression of e-mountains studies in China and abroad, this work proposed three key points to build digital mountains (China): 1) integration and sharing mountain information; 2) methods and models of mountain data mining; 3) visualization and 3-D simulation of mountain surface processes.

The Haiyuan fault is a major active left-lateral fault in the northeast edge of Tibet-Qinghai Plateau. Studying this fault is important to understanding current deformation of the plateau and the mechanism of continental deformation. IPTA (Interferometric Point Target Analysis) can be summarized as an iterative improvement of the model parameters to achieve an optimal match to observe interferometric phases. The analysis is done for a selected set of points which correspond to point target candidates, and is a collection of tools to exploit the temporal and spatial characteristics of interferometric signatures collected from point targets to accurately map surface deformation histories, terrain heights, and relative atmospheric path delays. Surface deformation in the Haiyuan fault is about 4-6mm/y.

Systematic scanning of the earth surface could be achieved for the first time in 1978, with the launch of the earth observation system NOAA-AVHRR. Some twenty years later, the SPOT-VEGETATION instrument introduced significant improvements at the levels of image quality, timeliness and availability. Since the start in April 1998, VITO is responsible for the central processing, archiving and distribution of the VEGETATION data. This paper briefly announces how a similar service is being established at VITO to provide the same kind of image data from the recently launched METOP-AVHRR.

The Zoige Wetland lies in the northeastern Qinghai-Tibet plateau, a region that is highly sensitive to global environment change because of its high elevation and cold environment; thus, it's a hotspot for land use and cover change (LUCC) research. In this study, we used Landsat images to monitor LUCC in this region using GIS techniques, as well as topographic, vegetation, and soil maps combined with field investigations. LUCC processes from 1975 to 2005 in the Zoige Wetland were gained through visual interpretation of multi-temporal remote-sensing images at a scale of 1:100,000. The monitoring result shows that the region's eco-environment degraded steadily in the 30 years.

A new generation of farmers can use aerial and satellite remote sensing imagery to help them manage their croplands more efficiently. By measuring precisely the way their fields reflect and emit energy in the visible and infrared wavelengths, precision farmers can monitor a wide range of variables that affect their crops. The management of their cropland can be adjusted dynamically based on the crop and environment status in their field. The key to precision farming is to acquire crop and environment information effectively. With the background of an extremely complex agricultural landscape in China, the limitations on applying remote sensing in field level crop and environment parameter monitoring to support precision farming were analyzed in detail and three major factors were identified: temporal and spatial resolution, accuracy and information dissemination service. A pilot study was provided in Yucheng, Shangdong Province of China. The crop and environment information were acquired instantly with remote sensing and delivered to farmers through a portable information servicing system. The information service has been proved to be effective in improving farmers' production while reducing the negative impacts of farming on the environment that are due to overapplication of chemicals.

This study analyzed spatial and temporal changes in land use in an irrigation district covering an area of 1.7 million ha in Northern China by GIS analyses and also investigated changes in landscape pattern using the landscape structure analysis program FRAGSTATS over the study period from 1986 to 2000. The decreases in farmland and the increases in grassland area mainly resulted from the policy of grain for green and converting slope farmland into pasture from China government. In spite of the efforts to conserve the fragile ecosystem, the land degradation, including soil salinization and grassland degradation, was spreading rapidly. The area of alkali-saline land increased by 22493 ha and about 50555 ha of dense grassland degraded into mid-density grassland. In terms of landscape fragmentation, both farmland and dense grassland showed the tendency of increased fragmentation. Both adverse natural conditions and human activities are responsible for the land degradation expansion in Hetao irrigation district, but the root causes are increasing population pressure and irrational human activities, such as flooding irrigation method and over-grazing. To prevent land degradation from spreading, population control and improvement of the management are prerequisite approaches.

Rapid urbanization is the main driving force of land cover change in metropolitan Wuhan. This is especially critical with respect to the many lakes and shallow water bodies. Land cover changes from 1991 to 2006 were mapped by classifying Landsat TM images (1991, 2002, and 2006). Different band combinations were used to build high-quality false-color images; the spectral separability of sets of training pixels was then evaluated by contingency matrices and feature space plots. Maximum likelihood supervised classification was applied to extract built-up areas, vegetated areas and water bodies. Post-classification was carried out to detect the land cover changes. From the classification, vegetation and built-up areas expanded at the expense of water bodies. Further comparison of the variety in LULC was analyzed in both temporal and spatial aspects between 1991-2002 and 2002-2006. The growth rate of built-up area from 2002-2006 is 55.7%, which is much higher than the rate from 1991 to 2002, whereas water bodies decreased more in the first period. Vegetation increased in the first period and then decreased slightly in the second. This analysis showed urban expansion is mainly along Yangtze River and along the East-West axis. These spatio-temporal characteristics should allow urban planners to better understand the processes of urban sprawl in Wuhan.

Relating supplementary cultivated land (SCL) quantity and quality with the occupied cultivated land (OCL) grade as well as realizing conversion between them are crucial to keep the balance between SCL and OCL, to protect the limited farming resources, to guarantee the security of national food, to harmonize the relationship between human and land resources, and to promote sustainable economic development. The Jianhan plain, one of China's grain production bases, was chosen for a case study to quantify the relationships between the grade index of farmland utilization and standard food output based on the resulting grade of agricultural land. Linear regression is used to model the relationships for 2778 samples from the grade of agricultural land obtained by field mapping. The average of grade index for different utilization grades was estimated by the area weighted average method. The results demonstrate that quantity-quality grade conversion coefficient of supplementary cultivated land, and the method used in this study are powerful tools to quantify the relationship between the quantity and quality of the SCL and the grade and realize conversion of OCL. Theses results can be used for protecting the quantity and quality of cultivated land and optimizing design for land consolidation project as well as determining the reasonable scale and layout of land use planning in the Jianghan plain.

Satellite remote sensing imaging systems have provided a spatially and temporally continuous and effective method to map the environmental and landscape changes over large areas on the earth's surface. In this study, multitemporal and multisource satellite remote sensing images, including Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), Enhanced Thematic Mapper Plus (ETM+) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), were used to study the environmental and landscape changes happened in Qinghai Lake area from 1973 to 2000. Change detection methods, such as image enhancement and false color composition, were used to highlight the environmental and landscape changes, i.e. lake area shrinkage, desert expansion and cropland area variation. Results showed that: lake area had shrunken by 275 km2 from 1973 to 2000; in contrast, the area of desert and cropland increased by 287 km² and 310 km² during the same period, respectively. As a result, remarkable landscape changes have happened: several sub-lakes have separated from the main lake in the east; the famous Bird Island in the west became a peninsula connecting with the land. Analysis suggests that environmental and landscape changes of Qinghai Lake area are mainly caused by natural factors and human activities.

Agriculture is one of the major economic sectors of Mongolia and the country's economy is very much dependent on the development of agricultural production. Being the rural and poorest conditions of Mongolia, 60-90% of its labor force employed in agriculture and agricultural sector has a prominent economic role. Mongolian agriculture has been successful in increasing food grains production in the past, guided by the goals of self-sufficiency in the country. The satellite imagery has been effectively utilized for classifying land cover types and detecting land cover conditions. Satellite image classification involves designing and developing efficient image classifiers. With satellite image data and image analysis methods multiplying rapidly, selecting the right mix of data sources and data analysis approaches has become critical to the generation of quality land-use maps. Objective of this study to monitor in the agricultural land cover changes in the Tov aimag, as there is important agricultural producing area in Mongolia. We have developed approaches to map and monitor land cover and land use change across in the Tov aimag using multi-spectral image data. In this study, maximum likelihood supervised classification was applied to Landsat TM and ETM images acquired in 1989 and 2000, respectively, to map cropland area cover changes in the Tov aimag of Mongolia. A supervised classification was carried out on the six reflective bands (bands 1-5 and band 7) for the two images individually with the aid of ground based agricultural monitoring data. Results were then tested using ground check data.

Two factors of the vegetation coverage and its types sensible to the ecological changes before and after the Emergent Water Transportation Project are investigated and analyzed in a qualitative and quantitative way based on the TM in 1999, ETM⁺ in 2002, ASTER in 2004 and the background data of the lower reaches of Tarim River. The research indicates that: (1) The moderate and satisfactory coverage of vegetation evidently go up in area by 1.68×103 hm², 9.09×103 hm² respectively. The poor, lower vegetation coverage areas constantly fall into decline by 7.83×103 hm², 9.99×103 hm² on the average from 1999 to 2004 respectively, and some turn for worse is prevented and stopped in some area. (2) The farm land increases from 1.48×104 hm² in area in 1999 to 1.51×104 hm² in area in 2002, and then to 1.72×104 hm² in area in 2004 with a yearly increasing ratio of 3.52%. (3) To be concluded, the emergent water supply plays an important role in promoting the ecological environment in the research region. But there is a long way to rejuvenate the whole Green Corridor and turn the extremely fragile ecological environment as a whole on a large scale.

The urban heat island is a phenomenon that the atmosphere temperature of the sky of the city near the ground is higher than the one outside the city, and it has business with the land use. Based on the Mono-window algorithm, the urban surface temperature of two imagines is retrieved by using of the Landsat TM data. The urban temperature is divided into five classes according to the mean-standard deviation, in which the first two classes are considered as the urban heat island. The geostatistics is used to analyze the change tend of the urban heat island and its centre of gravity. Then the images are extracted through a multi-step hierarchical classification method. Based on ArcGIS, the relationship of the land use and the surface temperature is analyzed. And the results show that the area of urban heat island increases and the trend of island expansion changes. The temperatures of different types land use are different and change as time goes by.

Spaceborne large footprint lidar (ICESat GLAS) has acquired over 250 million lidar observations over forest regions globally, an unprecedented dataset of vegetation heights. The ICESat Vegetation Product (IVP) was developed aimed at a global forest height dataset. Because of its high vertical resolution, large spatial extent and 70 m footprint characteristics, it is difficult to validate this product with other available remote sensing product or field measurements. To evaluation the IVP product in China, airborne waveform data was collected along several ICESat GLAS obits in the Southwest and West of China. The preliminary results show that the R2 is 0.41 and RMSE is 2.69 m between the vegetation height from airborne data and ICESat Vegetation Product at forest stand level in most cases. For those cases where the GLAS shots and airborne datasets gave very difference results, the airborne lidar data were synthesis to GLAS waveform and compared with the GLAS waveform. Those waveforms from fluctuated terrain also have several peaks and large waveform extent, which cased error in forest height estimation.

Land use/cover change is the main drive factor for the change of ecosystem carbon storage. To understand and appraise the carbon source/sink function of terrestrial ecosystem accurately, it needs to evaluate the impact of land use changes on carbon storage firstly. Based on data from remote sensing TM imageries in 1980, 1990 and 2005 in the region around Taihu Lake in China, the process of land use/cover change which divides to cropland, forest land, wetlands, grassland, settlements and other land had been explained, then the conversion matrix of land use change had been analyzed by GIS technology. Under the above, the paper calculates the change value of vegetation carbon storage in this area which caused by land use change with the method supplied by the 2006 IPCC Guidelines for National Greenhouse Gas Inventories. The main results as follows: (1) The area of cropland, forestland and grassland had decreased by 223.26km², 1,182.50km² and 178.90km² during 1980-1990, and the cropland had translated out to forest land and settlements mainly, the land types transferred into cropland includes forest land, grassland and other land, among which 1,463.90km² of forest land was transferred into cropland. The area of grassland had increased by 1,270.47km², adversely, the cropland and forest land had decreased by 5,929.51km² and 1381.94km² during 1990-2005, and the transferring-out object of cropland includes wetlands, forest land, grassland, settlements and other land, with only 59.95% of the original cropland remain unchanged. (2) The vegetation carbon storage had decreased by 642,171.27Mg because of land use change during 1980-1990, and the transferring from forest land to cropland has caused a decrease of 775,867Mg in vegetation carbon storage, that from cropland to forest land has caused a increase of 113,261.43Mg, that from grassland to cropland has caused a increase of 8,129.36Mg, and that from grassland to forest land has caused a increase of 12,304.94Mg; The vegetation carbon storage had decreased by 683,125.18Mg during 1990-2005, and the transferring from forest land to cropland has caused a decrease of 285,034Mg, that from forest land to grassland has caused a decrease of 417,617.73Mg, that from cropland to grassland has caused a decrease of 40,938.65Mg, while that from cropland and grassland to forest land has caused a respective increase of 52,856.61Mg and 7,608.59Mg. (3) The results of vegetation carbon storage change which calculated by the IPCC method had some errors in number value to other domestic research results, so the paper suggests the government of China should compile the greenhouse gas inventories which accord with it's own situation.

In order to search for new prospect areas of iron ore resources in Isabela, the Philippines, the comprehensive technologies of remote sensing and high precision magnetic method are applied, which can combine the macro-characteristics of remote sensing with the detailed detection of geophysics. Remote sensing geological characteristics, including the linear structures, the ring structures and the linear-ring structure combination are analyzed in emphasis. In addition, the high-precision magnetic measurement is carried out in the geophysical survey area. At last, by analyzing the distribution of the inferred magnetic body in the geophysical survey area and the relationship between the linear-ring structure combination and the two known iron ore occurrences, the prospecting model is established. In the study area, northwest or northeast trending faults combined with ring structures are beneficial to the mineralization, which is verified in the known iron ore occurrences. Five target areas which have similar metallogenic conditions as known iron ore occurrences are predicted depending on the model. It is proposed that further work should be done within 8 kilometers along the northeast side of the northwest trending piedmont regional fault and those hydrothermal deposits which correlate with intermediate intrusive rocks should be put emphasis upon.

Because of the capability of remote sensing to acquire synoptic coverage and repetitive data acquisition it has become a widely used technique for monitoring the effects of human activity on terrestrial ecosystems. This paper presents the spatial extent, magnitude and temporal behavior of land desertification around Holinguole caused by city expansion. The selected test area, Huoliguole City, is a typical grassland city in China that is located in the northeast of China. A time-series of Landsat TM images covering a period of 20 years (1987-2006) were used. The data sets were geometrically and radiometrically pre-processed in a rigorous fashion, followed by a linear spectral mixture unmixing model to extract feature images of vegetation and sandy soil. The biomass images were derived using a polynomial regression model based on the ground-based observations of the amount of grass and a vegetation index based on satellite remote sensing. By combing the vegetation fraction images, the sandy soil fraction images, biomass images, and PC (principal components) images, the grassland desertification information around the built-up area of the city was extracted based on BP (Back-Propagation) neural network algorithm. The results of our studies indicate significant expansion of the city over the last 20 years, and a similar trend was also observed in the temporal magnitude behavior of severe grassland desertification away from the city.

Time series of remote sensing data is widely used in vegetation change monitoring in regions of great environmental changes. In this paper, GIMMS dataset is used to extract temporal and spatial patterns of vegetation cover change in Huang-Huai-Hai Plain, China from 1993 to 2006. The results indicate that the total vegetation is increasing in this region. But the changing trend has spatial variations with some part improving and others deteriorating. The vegetation cover changed due to both human practices and climate changes.

As the main types of tidal flat wetland, the spatial and temporal variations of vegetation must have some influences on the ecosystem service and economic value of wetland. Based on GIS platform, the paper analysis the vegetation communities spatial and temporal variations of Shanghai Nanhui tidal flat, using four aerial satellite remote sensing data from 1995 to 2008, together with air photograph interpretation maps from 1949 to 1982, and field survey data results. The results revealed that the natural vegetation communities outside the shore bank extended to sea area with the tidal flat deposition; during 80-90 years in 20th century, the vegetation communities were in the transition period that from natural stage to man-made stage; After 2000, the vegetation communities were in the new pattern period with the artificial promoting deposition project and reclamation intensity increasing.

Time series of regional evapotranspiration (ET) of the typical oasis in the Tarim Basin were investigated and calculated by integrating remotely sensed surface parameters into the improved Surface Energy Balance Algorithm for Land (SEBAL) model. The distributed average and maximum daily actual ET was calculated based on the instantaneous ET, corresponding to oasis vegetation types for investigating the relationships between spatial difference of actual ET and land cover types in arid environment. Different land cover types and surface water conditions in the Keriya Oasis can be distinguished obviously in NDVI-LST feature space and characterized by the Temperature Vegetation Dryness Index (TVDI). Lacunarity index was employed to determine heterogeneity and spatial patterns of ET landscape in the Keriya Oasis by using RS and GIS techniques. Spatially distributed scale-dependent regularities of land cover types across a range of patch sizes were revealed by changes of lacunarity curves. It is explicitly suggested that lacunarity index is quite effective to quantify the scale-dependent ET spatial heterogeneity and useful to figure out the water use pattern of oasis-desert landscape.

Wetlands play a key role in regional and global environments and are critically linked to many major issues such as climate change, water quality, the hydrological and carbon cycles, and wildlife habitat and biodiversity. Mapping wetlands and monitoring their change are a long-term task. Remote Sensing characters with macrocosm, dynamics, quantity, and comparability will largely favor wetland research, especially radar remote sensing, which is not limited by climate conditions, has been proved an effective tool in wetland monitoring. In this paper, the unique polarimetric data of RADARSAT-2 is investigated for wetland classification. The target decomposition is used for optimum characterization of wetland target scattering. In this study, it is shown that the polarimetric information provided by RADARSAT-2 permits discriminating eight classes of land surface, and leads to an effective unsupervised and supervised Wishart classification of Poyang Lake wetland. Hence, the combination of RADARSAT-2's polarimetric and all-weather capabilities should provide unique information for operational mapping and monitoring of wetlands.

Riparian zone, as the interlaced zone between land and water, plays an important role in society, landscape and environmental quality. Riparian ecosystems have critical impacts on controlling the non-point source pollution (NPSP) and maintaining the health of aquatic ecosystems, especially on nitrogen (N) removal. The processes that affect N removal in riparian ecological system mainly include soil nitrous gas emission, plant uptake and sediment retention, of which nitrous gas release by soil denitrification is one of the most important functions for riparian system. Therefore, it's critical to build an N removal model including soil denitrification, nitrification and ammonium volatilization to evaluate the riparian ecological function and management practice. In this study, the Soil and Water Assessment Tool (SWAT) was extended with algorithms from a simple soil denitrification model and remote sensing data to enhance the model performance with regard to predicting soil N removal in the Guanting reservoir riparian catchment. The N removal model is based on chemical and physical relationships that govern soil heat, moisture and nitrogen movement. Processes considered include denitrification, nitrification and ammonia (NH3) volatilization. SPOT-5 and Landsat5-TM satellite data were used to interpret the spatial land surface information and derive model parameters. Results of laboratory-scale anaerobic incubation experiment were applied to estimate the soil denitrification model parameters for the different soil types. In an in situ field-scale experiment conducted to calibrate and validate models and an indirect method was used to test simulated N removal load in the Guanting reservoir riparian catchment. Results showed that the process-based model performed well and produced sound simulation results for the riparian reservoir catchment, with the coefficient of determination (R2) between the simulated and observed values being 0.71.

The sensitivity of near-infrared band to biomass decreases with the increase of vegetation density, while there is no significant change in red spectral reflectivity. Using SAR data to quantify the biomass usually suffers from the influence of soil humidity, surface conditions, especially those areas with low and middle biomass, resulting in the phenomenon that different biomass have the same or approximate total radar backscattering coefficient. In this paper, we have done research on the sensitivity to the biomass for three kinds of vegetation indices NDVI, RVI and DVI, and improved parameters of MIMICS model to simulate scattering components, setting up the simulation database of all backscattering components. And then we used Landsat TM and ENVISAT ASAR alternating polarization data with their reciprocal advantages, selecting the difference vegetation index DVI=0.45 as the threshold to divide the wetland plant into two parts. For DVI<0.45, we apply the statistical analysis methods to build a linear regression model with samples. For DVI>=0.45 the areas with high leaf density, it can be estimated by using C-band approximate microwave scattering models. Finally the entire wetland biomass of Poyang Lake is approximately 2.1×10⁹ kg.

In order to calculate the serious degree of geological disaster caused by earthquake taken place in Wenchuan county, Shichuan province, China with magnitude 8.0 on May 12th 2008, a method for extracting the changed vegetation using remote sensing taken the example of Minjiang basin from Moutuo to Xiao Shawan in Maoxian county, Shichuan province, China is proposed here. Because the study area has the characteristic of "high vegetation cover" (ratio of vegetation cover is 88.3% before earthquake takes place), changed vegetation can reflect the serious degree of geological disaster damage. Flow chart of this method is as following: Firstly, different spatial resolution between two images acquired before and after earthquake is uniformed and the two images are registered with accuracy less than one pixel; Then, vegetation changed map is made by extracting the difference area covered by vegetation in two images using Normalized Difference Vegetation Index (NDVI); Finally, statistics and analysis are performed according to the vegetation changed map. Results from vegetation changed map show that in the total area of 201.7 km², vegetation changed area is 24.4 km² in which 99.6% is caused by geological disaster with area of 24.3 km², and the 0.4% left is caused by the change of farm operations. Therefore, changed vegetation in study area is mainly caused by geological disaster. According to geological map and high resolution images acquired by airborne remote sensing on May 23rd 2008, for "high fragility and hardness" of limestone, phyllite and quartzose sandstone in study area, the type of geological disaster is debris flow caused by slacktip.

The aim of this study was to apply and to verify the use of Fuzzy Support Vector Machine (FSVM) for Landslide susceptibility evaluation. The goal of the study includes four stages: preparation of a landslide inventory of the study area, extraction of influential factors of landslide, calculation of fuzzy membership values and evaluation of landslide susceptibility based on FSVM. The developed approach was tested in the Putian,Fujian,China. Geological data and satellite images were collected, processed, and constructed into a spatial database using GIS and image processing. The chosen factors that influence landslide occurrence were: slope angle, elevation, all from the topographic database; lithology taken from the geologic database; vegetation index value and wetness index value, from Landsat Thermatic Mapper (TM) satellite images. Each of the above-listed factors was classified and coded using a numerical scale corresponding to the physical conditions of the region. Using those factors, landslide susceptibility was evaluated by FSVM method, and the fuzzy membership values were calculated by combining frequency ratio and fuzzy operator. The results of the landslide susceptibility evaluation were verified using landslide location data. The validation results showed satisfactory agreement between the landslide susceptibility evaluation map and the existing data on landslide location.

To simulate toxic gas dispersion over urban area with consideration of the influence of wind, buildings and other obstacles within the dispersion site, an integrated strategy incorporating computational fluid dynamics (CFD) and GIS technologies is investigated. CFD is able to couple wind field with pollutant dispersion process and provide realistic simulation for geometrically complex scenarios, however, inadequate of geometry construction for urban scale applications. This paper focuses on how to take advantage of the available GIS data, the visualization and spatial discretization capabilities of GIS in CFD modeling. Topography and building data stored in GIS database are used to extract the detailed coordinates and heights of the buildings around the area of interest. Furthermore, a methodology of domain discretization, with restrict to underneath geometrical boundary, is proposed to construct computational grids for CFD simulations. For illustration purposes, a mixed residential and commercial area of Lujiazui in Shanghai is investigated. The CFD software, CFX5.5, is employed to predict plume concentrations, and the output can be rendered dynamically in GIS environment.

The spatial variation of collapsing houses caused by the earthquake may be used to assess the earthquake damage intensity, and support the emergency decision-making process in rescue and recovery operations. We monitored the spatial variation of house collapse ratio in the 5.12 Wenchuan Earthquake by the aerial images, and analyzed the relationship with the earthquake intensity and assessed the afflicted population from the population and house collapse ratio. The house collapse ratio was derived based on the results of visual interpretation of the collapsed houses and noncollapsed houses by ADS40 airborne images acquired from May 15 to May 28, 2008. The results show that the houses were widely damaged in earthquake-damaged region; especially the counties of Wenchuan, Beichuan, Qinchuan, Mianzhu, Shifang and Pengzhou experienced the severest damage. The house collapse ratios, which are above 50%, mainly distributed along the surface rupture in a SW to NE direction from Yinxiu to Beichuan. When analyzing the spatial variation of the house collapse ratio and its relationship with the earthquake intensity, it was found the house collapse ratio and the earthquake intensity presented positive correlation. An index called the afflicted population which was derived by the house collapse ratio multiplying the population density showed a correlation with the actual fatalities population, which will be available to provide the reference information for the decision-making of rescue areas where the life of peoples may be urgently needed to rescue.

In order to monitor the surface deformation of Shuping landslide in the Yangtze River Three Gorges area, the method of differential SAR interferometry (DInSAR) using corner reflectors (CR) was applied. 12 CR, including 10 pyramidal corner reflectors (PCR) and 2 asymmetrical cubic corner reflectors (ACCR), were designed, made, and deployed on Shuping landslide. Based on the numerical test and the preliminary analyses of 5 ENVISAT ASAR images, we concluded that: 1) ACCR can provide strong response signal even without the best SAR look angle and is especially fit for the multi-angle applications of DInSAR; 2) given a simple phase model, the least square (LS) method can be used to analyze the CR's differential phase and get the accumulative deformation value.

The Ms 8.0 Wenchuan earthquake, occurred on 12 May 2008 in Sichuan Province, collapsed a great many houses and injured hundreds of thousands of people. Undoubtedly, it can be predicted that secondary earthquake landslides will draw much attention during a long time after the earthquake due to the severe geological hazard. In order to remove threat from the secondary disasters effectively, this study used techniques of remote sensing and GIS to generate susceptibility maps, taking the case of Wenchuan County. Seven factors controlling landslide occurrence have been taken account into the susceptibility assessment, including elevation, slop, aspect, lithology, seismic intensity, distance to faults and rivers. According to the probability that predicts the possibility of landslide occurrence calculated applying information value method and logistic regression separately, the study zone was ultimately categorized into five classes, specifically, "extremely low", "low", "moderate", "high" and "very high". These results have been proved to reflect closely the spatial distributions of landslides in the study area.

Wenchuan earthquake induced large-scale of collapses and landslides which blocked river channels and brought about quantities of dammed lakes. The number and the scale of dammed lakes are extremely rare in the world. Besides the backwater of the dammed lakes can flood the road traffic, villages and farmland on the upstream, it can severely threaten the safety of the people's lives and properties on the downstream. Once the dammed lakes burst out, they can cause severe flood disaster. Therefore, it is urgent to monitor the dammed lakes, study their distribution and analyze their development by means of remote sensing (RS) and geography information system (GIS) after the earthquake. In this paper, 145 high-resolution images were processed and 31 severely-afflicted counties were studied through RS monitoring and field investigation. By the time of May 28,2008, 257 dammed lakes existing more than 14 days were identified and there were 34 dammed lakes with capacity of more than 100 000m³. Based on these conditions, the distribution and development of dammed lakes were discussed and the findings showed that: (a) The dammed lakes induced by Wenchuan earthquake mainly scatter in Beichuan, Wenchuan, Shifang, Mianzhu and Anxian counties, and there exist 154 dammed lakes in these regions, which is 59.92 percent of the total. (b) 95.3 percent of the dammed lakes are within 10km of three major fault zones of Longmen Mountains and the relationship between the number of dammed lakes and their distance to fault zone accords with the law of logarithmic decrement. (c) Most of dammed lakes are distributed in the upper reaches of Minjiang River, Tuojiang River, Jianjiang River and Fujiang River, etc. in rosary. (d) The distribution of dammed lakes in the study areas is dominated by seismic intensity, lithology, slope and altitude. In the next 5-10 years, collapses, landslides and debris flows in the study area will occur frequently and severely and they are likely to block river channels and form dammed lakes. As rainy season comes, the risk of dammed lakes forming and bursting is increasing. So it is necessary to reinforce the real-time monitoring of dammed lakes, make risk assessment and formulate the emergency countermeasures.

Remote sensing technique provides an important way for screening oil seepage distribution areas in the early stage of marine petroleum exploration. This paper focuses on the studying of the evaluation method of natural marine seepage slick credibility by using ERS-1/2 SAR and ENVISAT ASAR data. The research is roughly divided into four main steps. Firstly, potential oil slicks are extracted from all images. Next, all oil slicks detected are further classified into several categories according to seepage slick credibility. The obtained oil slick information was then integrated into GIS database to examine the spatial distribution of oil seepage slick. Finally, the paper discusses the present problem on evaluating method. The result shows the potential capability of natural marine oil seepage detection with remote sensing technique for its advantage of low-cost and regional observation.

As global climates continuous to deteriorate, urban typhoons, rainstorms and other natural disasters increase in frequency. Urban flood control and disaster mitigation issues, which are related to the people's safety and property and the implement of the sustainable development, have become increasingly noteworthy. And with the rapid expansion of urbanization, these problems will be more obvious in the future. So it is crucial to study the problem of urban rainstorm waterlogging. In this paper, the study area is located in Shenzhen City in China, and the storm sewer model (Storm Water Management Model (SWMM)) was used to calculate relative data of the urban rainstorm. The methods of subcatchment partitions were studied. GIS technology was not only used to manage massive amounts of data, such as meteorological data, GIS data and pipeline data, but also used to obtain parameters for the model. Remote Sensing (RS) technology was applied in the land utilization classification and identifying water feature. The water depth in pipeline was calculated, the depth of the waterlogged area and the time that waterlogging lasted under different rainfall frequencies were calculated. The characteristics and the process of rainstorm water on the ground and in the pipeline were also analyzed. Lastly, the methods of integrating GIS and SWMM were studied, and a 3D dynamic simulation for the process of rainstorm waterlogging realized. The results show that the application of GIS and RS technology in the process of calculating can extremely improve the efficiency of calculation and the precision of its results. The 3D dynamic simulation realized by integrating GIS technology and SWMM offers a kind of prediction method with more direct-viewing and effective characteristics, which can be applied to establish flood-mitigation measures.

In a watershed of high cold alpine areas mainly supplemented with melted snow, glacier water and rainfall, the spatial distribution of runoff is extremely uneven over the whole region. With the development of DEMs and the advances on GIS technology, digital hydrology was developed, digital hydrology construction was enriched, and powerful technical support was provided to the discipline in recent years. Models can preferably reappear represent real hydrology processes; moreover the selection of partial parameters has the persuasive power to overcome the influences of artificial and subjective factors. Utilizing the technology of remote sensing (RS) and GIS the space distribution of underlying information, intermediate-state information and cover information of basin snow cover each time RS images are acquired and portrayed in the study of basin hydrologic processes. Based on the Xinanjiang Model, a digital hydrological model which suits streams mainly supplemented with melted snow, glacial water and rainfall in alpine regions was established. The model was applied to simulate snowmelt-runoff in 2005.The results were good and reflect the actual changing trend of in runoff. The deterministic coefficient of forecast projections is 0.812.

An experimental study was carried out in order to prove the feasibility of monitoring petroluem-polluted waters with remote sensing technology. The field data was collected in the rivers threatened by petroleum pollution. The measured items mainly included (1) the absorption coefficients of yellow substance, de-pigmented particles and phytoplankton pigments; (2) the backscattering coefficients data of water; (3) water quality parameters; (4) in-situ fine water spectral data. First, absorption spectral features and backscattering coefficients of petroleum-polluted water were analyzed. Secondly, the field spectral data were processed as corresponding bands of ENVISAT/MERIS using the spectral respond function of ENVISAT/MERIS in order to probe into the contribution of the various constituent concentrations in waters on the leaving-water radiation and remote sensing reflectance. The results showed that (1) with the increase of the petroleum pollution concentration, the absorption coefficients of petroleum-polluted water are also increased; (2) the spectra slope of exponential function of petroleum-polluted water is larger than that of petroleum-unpolluted water; (3) Emulsificated oil and decomposed oil in water can be absorbed by suspended particles and influence the scattering properties of the particles. Moreover it will change the spectral model of the inorganic particles backscattering coefficient with petroleum-polluted water; (4) the correlation between petroleum pollution concentration and remote sensing reflectance based on ENVISAT/MERIS is negative. These features of inherent optical parameters and apparent optical parameters obtained from the experiment provide the feasibility for monitoring petroleum-polluted waters with remote sensing technology.

From October of 2008 to February 2009, persistent drought weather hit most parts of northern China. The vegetation condition reflects the overall effect of rainfall, soil moisture, weather and agricultural practices. The remote sensing technique plays an important role in drought monitoring and early warning. In this article the author proposes a LAI anomaly index based on the MODIS 15A Products to monitor drought and predict yield. The historical average Leaf Area Index (LAI) images were derived using MODIS 15A Products from 2001 to 2007. The departure method was employed to calculate the anomaly index of LAI. And the LAI anomaly images were calculated from the MODIS 15A LAI products in spring, 2009. The LAI anomaly index was also designed to assess the drought degree. The spring drought index images in the 7 winter wheat provinces, including Heibei, He'nan, Shandong, Shan xi, Shan'xi, Anhui, Jiangsu, were mapped. The results showed that the spring drought was fiercely extended in the January along with the rapid rise of temperature and the regreening of winter crops, and also indicated the worst drought occurred in Henan province, Southwest Shandong, Guanzhong plateau in Shaanxi province, South Shanxi, North Jiangsu, North Anhui. However, the severe drought was also alleviated rapidly by the intensive and timely irrigation and the adequate rainfall from February to May, 2009. And the winter crops were successfully recovered since end of March (DOY 81) in most of the wheat product region. The predicted yield in most winter wheat product region was normal or better than normal level, and the spring drought resulted in small or bigger yield loss in some fields in south Shanxi, west Hebei, south-east Henan and Guangzhong Plateau Shaanxi.

Drought monitoring is very important for decision making in agriculture. In this study, Land Surface Temperature (LST) was retrieved by using single-channel algorithm. The normalized difference vegetation index (NDVI) was calculated from HJ-1 CCD data. With LST and NDVI, the Temperature Vegetation Dryness Index (TVDI) was obtained for drought monitoring. Taking the joint region of Shandong, Henan, Anhui, and Jiangsu province as study area, the TVDI data on February 19th, 2009 was calculated, and the distribution of drought intensity was further extracted by TVDI data. Also, the MODIS NDVI and MODIS-11 land surface temperature data obtained on the same day were used to calculate TVDI for the same area. Comparing the TVDI results with that obtained from MODIS data, the results from HJ-1 data were considerably accurate and effective. Therefore, HJ-1 satellite data can fully meet the need of national drought monitoring.

The coast of Jiangsu Province is famous for its radial sandbanks offshore. Dynamic changes of tidal creeks are difficult to survey for complex terrain and quick, multiple-changing. In this paper, medial axis methods of tidal creeks are focused on and then the concept of medial axis in mathematics is introduced and discussed. Voronoi diagram (V diagram) in GIS is also considered for its special properties. Points in every edge of V diagram have the shortest distance to the adjacent edges of polygon. Thus, medial axis extraction is converted to V diagram generation. Remote Sensing Medial Axis method (RSMA method) is presented for its quick and convenient survey and it is more developed than the previous traditional visual interpretation method. Using RSMA method, five main tidal creeks in the area were extracted and studied based on four TM images from 1988 to 2008 (They are 1988, 1995, 2003 and 2008, respectively). The results showed that through analyzing the medial axis in different times, RSMA method could reveal the dynamic evolution quickly and accurately. During the last 20 years, Xiyang deep trough has had the greatest changes as the west coast retreated back and the east extended east while the rest four tidal creeks have moved in the north-south direction periodically and gone straight gradually.

Nowadays a depth delineated in a chart is a static depth based on the chart datum, whereas what the ship navigation should consider is an instantaneous depth, namely, the sum of the static depth and dynamic tide height. Aim to the shortage in depth representation, a method to construct an instantaneous depth model based on a grid tidal model and chart data is proposed. Firstly, a regional grid tide model around China is developed based on the Princeton ocean model (POM) using "blending" assimilation approach, and the continuous spatial-temporal tide heights are predicted. Secondly, the tide grids serving for all depths in the chart are determined, the depths are located efficiently in these grids and corresponding tide heights are obtained. Finally, Instantaneous depths are computed and displayed dynamically. Experimental results indicate that the proposed method is efficient for dynamic representation of instantaneous depths, and is also accurate for the representation in wide and plane sea areas.

Considerable damage has been done to the cultural heritage sites around the world ranging from natural erosion to artificial destruction. With the development of information sciences, frontier technologies are actively introduced to help protect cultural heritage sites. The new concept of a Digital Cultural Heritage has been presented for culture protection and is gradually becoming an efficient method to solve or to remit various difficult problems. This paper puts forward a digitalization method for cultural heritage sites which rationally integrates and utilizes multiform surveying measurements. These techniques have been successfully implemented into two projects, namely the Digital Mogao Grottos and the Chi Lin Nunnery reconstruction. Our results prove that the concept of and the techniques utilized in Digital Cultural Heritage can not only contribute to research, preservation, management, interpretation, and representation of cultural heritages but can also help resolve the conflicts between tourism and protection.

The Northern-Five Lakes are a series of the lakes alongside the Grand Canal in Shandong Province, namely from north to south the Anshan Lake, Mata Lake, Nanwang Lake, Shushan Lake and Machang Lake. In history they played an essential role to the running of the Grand Canal of China for centuries. However, drastic decrease both in amounts and in extents happened during the past century. With the help of the remote sensing and GIS technology, using the multiple spatial data to monitor the changes of the lakes so as to get to know objectively the status and the changing trends in order to make an appropriate plan for better utilization, protection and management of the lake resources becomes possible and practical. This article utilized the map in 1907, the aerial photographs in 1954, MSS imagery in 1975, TM imagery in 1987 and 2001 respectively and SPOT5 multispectral imagery in 2005 to extract the spatial distribution of the lakes in that six periods by means of visual interpretation and supervised classification. According to the result, the decreasing magnitude, decreasing speed and the decreasing timetable of the lakes were analyzed, which would provide important reference to quantitative analysis of the change of the lakes.

To better understand the environmental and social problems accompanying the rapid urban growth, the SLEUTH urban growth prototype model was moved from UNIX based into Windows based to simulate the urban growth patterns in the Fuzhou metropolitan area during 1989 to 2003, and then to predict the future growth by 2020. The historic datasets required for the model were derived from the remote sensing images (Landsat TM data in 1989 and 1996, ETM+ data in 2000; and SOPT data in 2003) by using remote sensing and Geographic Information System technologies. Two specific scenarios of different urban growth policies were designed to simulate the spatial patterns of urban growth. The first scenario represents a growth with restriction only on water bodies. The second scenario depicts a controlled growth with additional protections on grass-covered lands and agriculture area. The results show that in contrast to the first scenario, the second scenario well controls the built-up area under the area planned in current urban development policies, and is predicted to lead to more sustainable urban development with less loss of resource lands.

This paper studies the urban spatial expansion of Xi'an City, the capital of Shaanxi Province of China, focusing on the temporal and spatial characteristics of the urban expansion during 1930-2002. Choosing Xian's built-up area as the study object and taking the geographic information system as the technical support, the paper establishes a series of Geoinformation Tupu to reflect the city expansion based on the Geo-information Tupu methods and multi-time remote sensing images, historical graphic document and data. It is proved that the spatial expansion had been expanding all the 70 years of 1930-2002 with different scales, paces, and directions. The build-up areas in Xi'an City had been growing outwards from inside circle basing on the ancient city with two expansion peaks and one nadir. By temporal analysis, it is founded that, firstly, the city expanded from east to west, then from north to south and finally from the center to outsides.

Ecological services are defined as the conditions and processes through which natural ecosystems and the species that comprise them, sustain and fulfill human life, or the goods and services provided by ecosystem which contribute to human welfare, both directly and indirectly. Ecological service value has been a hot topic in ecological economic research. Beijing, the capital of China, covers an area of more than 16,410 square kilometers and has a population of 14.93 million people. It's also a fast-growing city with rapid urbanization, which may significantly impact ecological services and functions. Such effects are difficult to quantify and are seldom taken into account in the policy making process. So this article tried a technical process for calculating the ecological service value based on remote sensing. Then the article estimated variations in ecological services value in response to land use changes in Beijing from 1990 to 2006, and provided useful information and advice to policy-making for sustainable development of ecological environment.

This study focuses on two problems in 3D visualization application for heritage site research. Firstly, methods for large scale terrain modeling and rendering were presented. Complex virtual environments were constructed with sequences of remote sensing images and DEM data. The algorithm of precise 3D scenes modeling was optimized. At the same time, the spatial index of quadtree and the images cache management strategies were introduced for improving the performance of interactive 3D visualization system. A novel method creating a mapping between 3D models and the image textures were put forward, so that the models and the textures can be managed respectively. As a result, the capacity of massive 3D terrain surface models management was enhanced as well as the real-time rendering was accelerated. Secondly, methods for 3D culture relics modeling were presented. The culture relics and ancient buildings of the Canal were simulated, which will contribute to its reconstruction and protection. Some ancient water facilities such as ship-lock and docks models and animated navigation scenes were created based on the construction principle and architecture of the Canal transport hub.

The Chaohu Lake Basin is an important area for ancient human activities in East China. The Lingjiatan site, which is located at the southeast of Chaohu City, Anhui Province, and 35 km north to the Yangtze River and 5 km south to the Taihu Mountain, is the most representative Neolithic Age site with advanced jade-carving techniques in this area. The 14C date of Lingjiatan Site is about 5600~5300aBP, the same time as the Hongshan culture and earlier than the Liangzhu culture, which falls into the Mid-Holocene epoch. Based on mid-high resolution remote sensing images and former archaeological materials, combined with field investigations and sampling analysis of the archaeological site profile of Lingjiatan Site as well as core drillings in the Chaohu Lake, the paper reconstructs the climate environment of the Lingjiatan site and the environmental background of ancient human activities during Mid-Holocene. The research results show that: (1) The ancients in Lingjiatan lived in the Holocene Optimum, its culture development was during the interim phase when the climate transformed from warm and wet to cool and dry. (2) The ground surface deposited in the last phase of late Pleistocene epoch (OSL dating is 11.6 ±1.0 ka BP) was the living ground for Lingjiatan ancient humans. The sedimentary discontinuous surface may be caused by strong fluvial erosion under the warm and humid climatic conditions of the Mid-Holocene. (3) Originally, paleo-geomorphic surface was a level shallow mesa foreside southern part of Taihu Mountain, but was cut by fluvial waters and the geomorphologic configuration formed "finger-like" features alternately with strip hillocks and rivers. These features can be seen on the Landsat ETM+ remote sensing image, especially the depression area. This depression is now cropland, and was interpreted as the palaeochannels. (4) Based on the remote sensing image interpretation, the site was in a "peninsula shape" environment which had rivers flowing around the east, west and south sides of the Changgang terrain and that was good for rice planting, hunting, fishing and water transportation. (5) The most particular characteristic of the Lingjiatan site is the advanced jade production, those maybe have some relationship with the convenient shipping, trade exchanges and optimal environmental conditions, which was also conducive to rice cultivation.

Because of natural contribution and man-made disturb, segments of Ming Great Wall in NingXia province and Shaanxi province were mostly destroyed, even more some of them were disappeared from the surface of earth and buried by sand. It is not an easy thing to detect the Great Wall by field survey since it is quite long, and fieldwork needs a lot of human and financial resources. It is not an easy thing to detect the Great Wall by field survey since it is quite long and fieldwork needs a lot of human and financial resources to detect the Great Wall by field survey since it is quite long, and fieldwork needs a lot of human and financial resources. In this paper, remote sensing technology was used such as SAR and optical remote sensing, pixel image fusion between SAR image and optical image was achieved, and then skeleton method was tested to automatically generate the Ming Great Wall based on the fusion image and the test got satisfied results. Finally, the spatial location information of the Ming Great Wall was produced successfully.