Because of the global climatic variations and the anthropogenic destructive influence on local environment, the ecosystem is altering, even affect sustainable development. It is very important to diagnose whether the ecosystem is healthy. In Northwest of China, the ecosystem and ecological environment are brittle as the desertification，soil erosion seriously, and sandstorm break out in high frequency. In this paper, Shandan County in Gansu Province was selected as a typical study region in arid and semi |arid areas. The pressure, vigor and resilience were selected as three indicators for modeling ecosystem health diagnoses. The pressure was derived from actual livestock; the vigor is represented by annual max NDVI in each grid and the resilience is range between NDVI max and min. The results show that the ecosystem health in Shandan County degraded remarkably, mean health index of all grids was 0057 2 in 1990, while 0.032 2 in 1999, declining 43.7％; During each year in Shandan County, relative high values of ecosystem helth exist at military horse farm, where the high overlay grassland is dominating; A few highest values exist at southernmost medium and high overlay grassland, surrounded by shrubs; The value of grass in other place is low, occur at most part of northern Shandan Connty.
With characteristics of “synthesis, multi |band and rapid message updating”, ETM image has been regarded as a most important technology in the study of resources and environments. Aiming at the need of constructing ecology Greenland information system in Shenzhen city, this paper focuses on the best methods of obtaining Greenland information of Shenzhen city. Because optimal bands selection is the most important parts in remote sensing image enhancement, we introduce three methods in image enhancement, such as basic bands combination，minus operation, NDVI combination with other bands. Studies show that NDVI combination with other bands is an ideal method for extracting Greenland information in Shenzhen city, meet the need of monitoring ecology Greenland of city, using this method to analyze distribution of urban Greenland cover can help government to plan and manage green land.
Multitemporal remote sensing images change detection has been employed in land u se and land cover change widely. The radiometric normalization of multitemporal satellite optical images of the same terrain is often necessary for land cover c hange detection. An automatic and robust relative radiometric calibration method for multitemporal remote sensing images is introduced in this paper. The select ion of pseudo |invariant features is done statistically. With quality control, l e ast absolute deviation (LAD) is used to find linear relationships between multit emporal images of the same area. In order to eliminate the influence of change a rea, change area is got rid of with the help of regress line. At last, the radio metric calibration parameter is improved iteratively based on the slope of the r egress line. The new procedure is applied to two Landsat Thematic Mapper (TM) im ages from different years (1997 and 2003) and of the same area. Results show tha t the error in radiometric consistency between the multitemporal images is reduc ed effectively.
At present, the requirement of geo-spatial data sharing is becoming more and more compelling. Though there are huge geo |spatial data available, it is extremely difficult for users to get data they want efficiently and exactly. The metadata of earth science data which is called geo |spatial metadata allows a producer to fully describe a dataset. So users can understand the assumptions and limitations and evaluate the dataset's applicability for their intended use. In this paper, geo |spatial metadata and the metadata standards for geo |spatial data are introduced firstly. Then based on the metadata standards, the paper illustrates the architecture of Metadata Catalog Service and the model of GIS Portal which is based on the Metadata Catalog Service, providing the solutions for better data sharing and enabling the users to get the geo-spatial data they demand exactly in the most efficient way.
By the end of 2003, the total mileage of being used expressway of Shandong provi nce is the longest in the whole china. Constructing information system of engine ering geology of the province not only is in favor of information of regional ma nagement of expressway, but also owns function to maintain; construct and plan t he expressway. In the course of constructing the information system, the GIS sof tware ArcInfo was acted as a tool to collect and dispose data. GIS software ArcV iew with its script language | Avenue; GIS software MapObjects based on COM tec hnology and Visual Basic 6.0 were used as platform. Combing with DDE technology, the system realize communicating between two soft wares. As a result, the syste m realize image query on engineering geological information of sampling spot of the expressway. By constructing Active X object of the EXCEL, the system realize dot |beating inquiring information of one random spot on the expressway network , and The information which includes engineering geology; geological disaster an d the section of the route. With these functions, the system has been proved to be an usable engineering geological information system.
Groundwater monitoring is the only way to directly get dynamical data of groundw ater quality and quantity. With the development of society, more and more ground water is being pumped. To gain enough information for groundwater management, mo nitoring network has been established widely. Groundwater monitoring management information system based on GIS is a kind of computer system to deal with lots o f monitoring information with different sources and structure. The paper analyze s monitoring information and function of GMSMIS, designs a kind of mixed archite cture of Browse/Sever and Client/Sever, and with an example shows a development draft with four layers of information collecting layer, data serving layer, appl ication serving layer and application layer.
This article explains the general character of the environmental emergency treat ment and general approaches for environmental emergency management by geographic information system (GIS). With the instance of severe arsenic pollution of Xian g River in Hengyang district, Hunan province, this paper mainly discusses the ap plications of GIS in settling emergent heave metal pollution, and gives the guid elines of using GIS to solve the emergency effectively with the least loss, and search the most optimum approach to solve this problem. From the visible result we can find the advantage brought by GIS to solve heavy metal pollution and the paroxysmal environmental accident.
