The Ecological Risk Evaluation Based On Ulgai River Basin Of Xilingol League

The ulgai river basin of Xilin Gol League,which is located in the northeast of Xilin Gol League in the Inner Mongolia Autonomous Region, is an important ecological barrier for export in Northeast China, and is the largest inland river as the main component of Ujimqin grassland in the territory of the Inner Mongolia Autonomous Region, has an important effect on the survival of Ujimqin grassland decision, In this paper, the author has made the ecological environment of the Ulgai River as the research object,then started with the aspects of natural factors lead to ecological disaster, risk identification, established risk evaluation index system and found the ecological disaster risk index and regional levels of Ulagai in five period (1990,2000,2005,2010,2013),who considers the typical ecological risk, five TM images (1990,2000,2005,2010,2013) as the main data source, combines with remote sensing, GIS technology and other modern technology and Excel, SPSS and other software tools and methods of mathematical statistics and also explored and provided scientific basis for the corresponding countermeasures of ecological disaster.In total, the level of risk of the ecological environment status on the whole Ulgai River Basin in five period during 1990-2013 is always low, which showed a decreasing trend of ecological environment condition, but no obvious change during the period from 1990 to 2005, indicating that the ecological environment status in WULAGAI river basin is relatively stable. The ecological environment in the period from 2005 to 2013 (AEI) shows an increasing trend, which shows a good ecological environment in the area. And the ecological environment index (EI) was higher than 75, which is said that Ulgai river basin is owing a high vegetation cover, all-round of biodiversity, ecosystem stability, and especially is suitable for human survival area. From the perspective of the whole ecological environment, the cover area is good and stable, but still has some differences in the numerical evaluation index in different years.Through the used types "vulnerability" of the WULAGAI River Basin in different land:it can be seen that the WULAGAI river basin ecological environment has improved with the risk of not too obvious boundaries and the risk decreased in the time series of the study area. High risk areas mainly distributed in the southwest and northeast, which distribution is more dispersed, and the land use types of high risk area is mainly farmland and mused land. A high risk area is mainly distributed in the high risk region of the surrounding area, as well as the Northwest. A Land use type of high risk area is mainly low coverage degree grassland. Throughout the Medium risk areas of the WULAGAI River Basin, the area is larger, but mainly distributed n Northwest area. Land use types in medium risk areas are mainly high coverage grassland. It mainly distributed in low risk areas around the low-risk areas, and the lower risk area of land use type is a part of the main shrub land. Low risk area is mainly distributed in southern and southeastern regions, especially in West Ujimqin banner in the southeast, in addition, there are also scattered distribution of the central and North regions. The main land use types of water and land.