The optimization approach is one of the most promising methods for retrieval of vegetation parameter from canopy reflectance model based on optical remote sensing data. In this study , a canopy reflectance model ( SAIL, Scattering by Arbitrarily Inclined Leaves) is adopted as forward model and three different simulated annealing algorithms( Boltzman simulated annealing, fast simulated annealing and very fast simulated re-annealing ) are developed as global optimization scheme to simultaneously retrieve leaf area index and content of chlorophy ll, respectively . The Sum of Squared Residuals (SSR) between spectral reflectance by SAIL model and by observation is selected as cost function. The performance of these algorithms is demonstrated with simulated data sets. We can draw following conclusions: ① this algorithm is able to escape local energy minima and can converge to a global energy minimum; ② the very fast simulated re-annealing algorithm priorto Boltzman simulated annealing and fast simulated annealing ; ③under no noise conditions, we can obtain the estimation of leaf area index and chlorophyll content accurately .
As the most important part of Zoige wetland, Zoige county is a typical representation of alpine ecosystem in Tibetan Plateau. The LUCC characteristics of Zoige county in the past 15 years are investigated and analysed by using Landsat TM sensor data of 1989, 1997 and 2004 with themethod of geographic information system (GIS) and statistics. Themain results are as follow: ①Themain types of Land use/Land cover in research area are grassland, marsh, woodland and bareland. Since 1989, the area of grassland and marsh has been decreasing with bareland increasing rapidly. ②By establishing mathematical models in the range, quantitative and spatial dynamic change, trend and state index of LUCC, the spatial-temporal characteristics of LUCC can be deeply studied. In the period of 1989-1997, the trend and state index of the whole research area was 0. 37, which means the state was quasi-balanced. In the period of 1997-2004, the index was 0. 23 which is smaller than former period and indicate the state of LUCC was balanced. In the whole period (1989～2004) , the state of the research area LUCC was quasi-balanced with the transitional process in bi-direction. ③Through analyzing Land use/Land cover change spatially ,we found that grassland and marsh of this area degenerated sharply with the degraded area transferred spatially from the two periods.
In the prehistoric time, there was a large uniform terminal lake named Zhuyeze in the lower reaches of Shiyang River. Along with the climate change and human activities, Zhuyeze began become separated and dry gradually. Lots of small lakes vestiges were left behind in this area. Among them , Baijianhu Lake is the largest. This article take TM image as the data source, after image enhancement, a group of alternate-color stripes which exist on the north bank of Baijianhu Lake were high lighted. After interpretation, analyses and investigation, 8 of them were confirmed as the once lakeshore lines. Using 1∶50 000 DEM , the modern altitudes of these linesw ere obtained and the corresponding areas were calculated in GIS environment. The results show that the highest elevation of Baijianhu Lake was once 1 320 m with the area 1 600 km2. After that, Baijianhu Lake began shrink until dried completely in last century.
Because of the character of hyperspectral remote sensing data, it is necessary and urgent to develop hyperspectral data process algorithm. In this paper , some hyperspectral data process algorithms for feature selection and feature extraction was discussed, and its advantage & disadvantage was analyzed. In particular, we studied derivative spectral algorithm and put forward quad-encoding algorithm as the improved the binary encoding algorithm. Using the algorithms this paper proposed we extract spectral absorption parameter. The experiments have demonstrated that quad-encoding algorithm has the better performance than binary encoding on hyperspectral data, and for derivative spectrum it is effective to indicate
validate feature for objects when its rank is higher.
This study is aiming at exploring the annual changes in vegetation Indices under complex topographic conditions of the Xinglong-Mountain National Nature Reserve featuring mainly natural forest , and serves as data baseline for monitoring the forest eco-system, and comparing to the ecological restoration from tillag eretirement . With methods of the ROI( region of interesting) in ENVI4. 0, ARC/ INFO AML programming , and atmospheric calibration based on the reflectance of local pond and standardized-bared highway surface, a vector database for compartments was established automatically. It contains 3 datasets for vegetation indices ( VI) namely DVI, NDVI and the Greenness of Tasseled Cap, the climatic statistics in July-August of 2000, 2001 and 2002, and topographic factors respectively , so comparisons among the VI's of the woodland divisions and analysis on them to the standing conditions were approached. With a very slight increase ( 1. 11% ) of the NDVI as an exception in 2001 to that of the 2000, all the VI' s in the year of 2001 and 2002 dropped largely ; Annual changes of the three indices for the deciduous are the biggest while conifers or conifer-deciduous mixtures are the second with the NDVI changes amounted only 1/ 3 to1/ 7 to the former ones, and the springwood or the afforestable land are the smallest . The conclusion is that the sensitivity and adaptabilities of three main forest divisions to the ecological factors are thus ranked, and great changes in magnitude of VIs may resulted from extremes of ecological factors. Further in-situ investigations of compartments and ecological modeling for RS monitoring ecosystem of this Naturereserve are needed.
The applicability of Kriging method used to interpolate borehole geothermal data of Qinghai-Tibet railway. The experimental variogram can be fit with linear of Nuggut and Gaussian model regionalization. The result shows in terpolation value is smaller and have a big error up - 5m and interpolation value is bigger and have a small error down - 5 m. Volume visualization of borehole geothermal data is implemented with Voxel model. A series of isosurfaces of depth are generated using Kriging along horizontal,then the Voxelmodel is generated by stacking the isosurfaces. The visualization is implemented by indirect volume visualization in IDL.
This paper summarizes the application of ASTER data. Especially, to the forestry management,the paper describes the way how to extract image data form ASTER HDF file data by programming. The reasons and the keymethods are also demonstrated. The study also cites how to recognize themain species of trees from multi-spectral image data by fusion. In order top roduce high density parallax image from ASTER stereo-pairs at band 3N &3B, the method also has been provided in this study. Stereoscopic vision technology is used forming stereo-forestry, particularly in recognizing main species of trees along DEM.
The unrestricted expansion of oasis would lead to serious environmental problems. Water is one of the key factors which influence the stability of oasis ecosystem , and it’s important to research the relationship between the water quantity and appropriate oasis area. The goal of our study was to evaluate the appropriate oasis area basically keeping the natural ecological balance. The main data included Landsat 5 TM image in 1986, Landsat 7 ETM + image in 2000 and social statistical data. Results showed that: in 1986, the oasis area was less than the appropriate oasis size, reflecting that there is an capacity fqr the expansion of oasis, but the area of farmland has exceeded the appropriate farmland; in 2000, both the oasis area and the farmland area have exceeded the appropriate values which are the threshold keeping the natural eco logical balance. During the period from 1986 to 2000, the security degree of oasis area decreased from - 0.137 to -0.216 . Our results also indicated that the water quantity in Jiuquan oasis couldn’t maintain the ecological balance. It’s necessary to accurately allocate the use of the limited water resource in study area and return over-reclaimed farmland to forest or grassland in order to keep the sustainable development of jiuquan oasis.
Assisted by GIS, the annual average Temperature and Precipitation in Xinglong Mountain area are analysed with longitude、latitude and altitude based on DEM and Conventional Statistical Model ( CSM ) . The measured values from the 9 weather stations are substituted into the equations which are built in the process of regression analysis to create Temperature and Precipitation grids. The residual values are dealed with Kriging . Aiming at the different rules of Temperature and Precipitation, annual average Temperature is accommodated by Topography-Adjusted Statistical Model ( TASM) on the small scale,the tempreture vertical gradient is calculated and the difference between the temperature of northward and southward slope is compared; the annual average Precipitation is modeled by Parabola model. The results of modeled Temperature and Precipitation distribution accord with the truth on the whole.
In this paper, we used the thermal infrared band of Landsat25 TM to estimate Land Surface Temperature (LST ) with Q in’s mono-window algorithm. These results show surface temperature of water body and oasis are low; and desert and gobi are high. These results are consistent with the relation of hydro-thermal. So this mono-window algorithm can be used to estimate spatial distribution of landsurface temperature over Zhangye oasis.
Water and soil conservation ecological rehabilitation is an effective measure of environmental protection, which mainly depends on self rehabilitation ability of nature and under the precondition of strengthening preventability protection and the assistant measure by manpower. The water and soil loss in large area would be controlled initially in a shorter time period and the regional environment will be restored step by step , and the harmonious coexist between human and nature will be realized finally. The Liangdang County is located in the southern Qinling Mountain and in the Jialing River water system ,
which belongs to one of the eight experimental counties of implementing the Water and Soil Conservation Ecological Rehabilitation Project in the upper reaches of the Yangtze River. The study area with total area of 327. 26 km2 was selected in the northern county where was the key region of water and soil loss and the ecological rehabilitation project was carried out from 2001 to 2003. In order to cooperate with the evaluating of the project, the Remote Sensing (RS) and the Geographic Information System (GIS) techniques were used to perform the monitoring and analysis in the study area. The change status of environment types in study area and the assistant measure effect of returning forest and grass from cultivated land, convert ing slope cultivated land into engineering terrace and catchments irrigation in the ecological rehabilitation were evaluated by remote sensing monitoring at the beginning (2001) and after 2 years (2003) of carrying out the project, contrast analysis combined with referencing conventional observation data. The research results showed that the vegetation status have changed obviously since carrying out the project, the coverage rate of vegetation raised from 86. 50% to 98. 04% , increased by 11. 54% , which also showed that the environment develops toward reversion direction. The higher resolution satellite data (TM , SPOT 4, and SPOT 5) can be used for remote sensing monitoring in ecological rehabilitation project and effect evaluation of the project actualizing.
The northwest China belongs to arid and semi-arid regions. It’s vegetation is extremely sensitive to the change of climate and temperature. The change tendency of vegetation may reflect the climatic change and forecast climatic change tendency in the future. Remote sensing NDVI data with 22 years long time series during 1982 to 2003 were divided in to four periods (1982～ 1987, 1988～ 1993, 1994～ 1998,1999～ 2003). The average SINDVI during these four periods were calculated separately in northwest China, which was reclassified according to different SINDVI levels and transformed into patches. By using landscape ecology methodo logies, the spatial pattern and dynamic change characteristics of every period patches were analyzed. The results indicate that the vegetation has increasing and improving trend mostly in northwest China. But local regions exist degenerating trend.
Shandan County is taken as study area which is the typical region of the grassland vegetation in the middle and upper reaches of Heihe River basin and the key region of ecological and environmental construction. First, correlation between vegetation indices and grassland above-ground biomass is analysed based on in situ sampling data acquired in August, 2003 and remote sensed image data in the same periods.Then, estimating model of grassland above-ground biomass based on remote sensed data in Shandan County is established. Results show remote sensed data corrected by field sampling data can achieve a close correlation with grassland above-ground biomass. Grassland above-ground estimating biomass model can be expressed by the equation: Y = 2477X - 77. 598 (R 2= 0. 7589). Verified by in situ sampling data, the model has a better estimating result.
The establishment of spatial data structure includes the relation between the system function and the data, the classification of data and the codes, the importation of the data and edit etc. This text researched the distribution and variety regulation of precipitat ion, interception, throughfall, stemflow runoff , evapotranspiration of Picea crassifolia in Qilian Mountains. The results indicated that the total precipitat ion was 433. 5mm and the throughfall 287. 37 mm; stemflow 0. 294 mm, interception 145. 83 mm,taking up to 66. 29% , 0. 068% and 33. 64% of the total precipitation respectively . and the runoff was 239.98 mm which took up to 55. 36% Evapotranspiration. water storage in soil and that in litter were 156. 54 mm、23. 63 mm and 7. 92 mm respectively.Taking up to 36. 11%, 5. 45% and 1. 83% of the precipitation respectively .
The digital roadbed and simulation platform constructing of Qinghai-Tibet railway provided powerful support for the data management, analyses and use during the Qinghai-Tibet railway engineering and science research process, as well as the process of design simulation evaluation and spatial decision-making support. As at radeoff between constructing cost, constructing cycle and developing difficult, the object system was implemented in two different version, light weight version and high weight version. Two versions aimed at different system requirement. The light weight version was designed for supporting the field scientific work. The high weight version was designed for the distribution application and spatial decision making support.
Generally a decision support system (DSS) helps decision making by using mathematic models and numeric computing methods, which requires decision makers to be familiar with models and data to some extent. Heihe hydrological and water resource decision support system (HDSS) has incorporated and will continue to incorporate a set of models, including SWAT , TopModel, an empirical water resource predicting model, and a common time-series model. The structure and parameters of these models are commonly too complicated to learn in a short time. This situation will prevent decision makers from using them. An applicable solution is to integrate an expert knowledge support in to HDSS. In this paper, a common expert system developing tool, C Language Integrated Production System , i. e. , CLIPS, developed by NASA , will be used to implement the knowledge support for the HDSS. By CLIPS, HDSS will be benefited in at least three ways: ①selection of a most appropriate model for the specific hydrological or water resource concern, ②setting of proper model parameters, as well as ③analysis of the outpu t yielded by the selected model. A simple example will be presented to demonstrate the use of CLIPS in the HDSS for facilitat ing the selection of appropriate model (s).
The section o f ChuanZang road in Tibet has many geological hazards, and lots of researches and projects had been done in last fifty y ears. Constructing hazard information system is very important to manage and reconst ruct the road. This paper focuses on the design of Geological Hazard Information System of ChuanZang Road. A GIS Component , named as SuperMap component , was used to develop this system which can assist the users to know the climate background of the hazards, the distribution of the hazards and the status of handling the hazards along the road.
Noise pollution has complex spatial distribution, tradit ional evaluation methods achieve accurate,direct-viewing effects with difficulty . This article take the university campus as an example, has discussed the application of GIS method in the evaluation of regional ambient noise. The research indicated that , GIS method is an ideal technologic tool in evaluating regional ambient noise and has good application prospect .Whole integrating simulation models of ambient noise with the GIS platform is the important way to improving the evaluation methods of regional ambient noise.
Provincial documents compile the provincial situation as the foundation of the provincial situation system characterized for its material, universality and continuity. In the case of information aggregates of the multiple-source and variant provincial situatio n, application of information fusion theory could resolve problems in integrating information. The present paper exploited the information fusion theory and its applications in different degrees of digital, character and decision through the analysis of multiple-model variant provincial situation information such as spatial basic data and civil economical data.
Gansu situation information system is a compact program for government affair . The information promulgating platform was built used the technique of WebGIS, through which guests could browse and search the visualized and imagewise provincial situation. The present paper introduced the structure and functions of the platform of WebGIS in Gansu Situation Information System and probed into the model of WebGIS in the electronic-gov ernment affair.
With the development of GIS techniques, large numbers of geographic data were produced and accumulated in different systems, equipments and sites with various memorial formats, which resulted in the negative effects on the data' s interoperation, sharing management and integrated utilization. New techniques such as internet , distributed computation and spatial data-base brought a scarce opportunity for spatial data sharing management . Based on analyzing GIS data interoperated technique, the present paper studied the mechanism of data interoperation which aimed at the multi-source heterogeneo us spatial data and proposed solutions.
The water and soil conservation digital management in the Loess Plateau is a challenge and a hard task in the water and soil conservation of Yellowriver in the 21 century , the monitoring of water and soil conservation will be a foundation and will have a very important station in the areal digital management .We expatiated the concept、characteristics and holistic frame of water and soil conservation digital management in this paper; and we probed into the composing of water and soil conservation monitoring system based on the digital management in the Loess Plateau, we also studied some key technical taches such as the requirement and classify of water and soil conservation information, the lay of stations and net of water and soil conservation monitoring, the method of information collection, the foundation and update of database etc.
Component GIS enables integration of GIS and customapplications in a rapid and easy way.ArcEngine from ESRI is a powerful component GIS, built upon the ArcObjects, the underlying GIS class library common to the entire ArcGIS family software. This paper will demonstrate how to implement an application framework based on ArcEngine under VisualBasic environment. Such framework will incorporate map displaying, querying, and some basic spatial analysis functionality for both vector and raster data. Concepts of component GIS and knowledge on ArcEngine will be presented in this paper as well.
Although the Normalized Difference Vegetation Index (NDVI) time-series data derived from NOAA/AVHRR, SPOT/VEGETATION and MODIS, has been successfully used in research regarding global vegetation change, land cover classification and biophysical parameters inversion. However, due to effect of cloud and atmospheric conditions, residual noise in the NDVI time-series data will induce erroneous resultsin our further quantitive analysis. In this paper, some general reconstructing methods are introduced, including Maximum Value Compositing (MVC) , the Best Index Slope Extraction (B ISE) , Media Iteration Filter (MIF) , Temporal Window Operation (TWO ) , Fourier Transform (FT ) and Savitzky-Golay Filter (S2G Filter). With the development of change detection research, it is necessary to reconstruct the NDVI time-series datasets in order to provide high-quality data for the study of vegetation response to global climate change.
Orbit ephemeris and camera data are needed for strict geometric rectification of CBERS CCD image,which are unavailable in practical applications. As a result , the average polynomial, rational function model( RFM) and rubber sheeting methods are used for the approximate geometric rectification of this kind of imagery. This paper first introduce the several approximate rectification algorithms, then list the result of analysis and precision comparison of different approximate rectification algorithms using testing CBERS CCD images. Experimental results show that the precision stabilization of RFM method is the best , and RFM method support ortho-rectification. The polynomial model is the most efficiency method. The precision of Rubber Sheeting method varies with the number and spatial distribution of control points.
A new investigation of landuse changes will be carried out under the ministry of land and resources which will construct a new system of land investigating methods and managements. The new investigation can obtain comprehensive and wide-ranging results respect to the first land investigation during 1980' s through making full use of new techniques. This paper discussed the orthor ectifying method for SPOT 5 satellite image practicing in continuous SPOT 5 images in large scale concerning the second investigation of land use changes. The engineered management of SPOT5 was introduced, and the methods of accuracy evaluation according to the error of the site-selecting , digital elevation model and endogenous factors of the transducer were expatiated.
