关键词: 区域生态风险, 概念模型, 评价, 鄂尔多斯

Abstract: A conceptual model of ecological risk assessment is built, which includes the following procedures: to determine the objectives of risk management, to analyze risk probability, to choose appropriate assessment methods, to characterize assessment results, and to make risk management. Ordos, the study area, is located in the farming-grazing transitional zone of northern China. On the basis of Landsat TM images, historical records, survey data and socio-economic statistical data, the authors make the regional ecological risk assessment of Ordos in 2000 and 2008 using the RS, GIS and SPSS. The stressors such as drought, flooding, pollution, strong wind, sandstorm, desertification and soil erosion, are selected as the risk sources. Also, the index system of regional ecological risk assessment is set up. The results are presented as follows. The spatial differentiation of ecological risk level is evident in Ordos. The regions with high risk distribute in the Kubuqi Desert, Waowusu Desert, and Zhungeer and so on, which is directly related to their adverse environmental background and economic activities like large-scale mining. In 2000, the regions with moderate or high risk level mainly lie in the Zhungeer, Dalate, the Kubuqi Desert in Hangjin, and the middle, north, and southwest of Wushen. In 2008, the risk of most areas is lower. However, there are some exceptions, for example, the areas such as the middle and southwest of Dalate Banner, the northwest of Dalate Banner which lies in the Kubuqi Desert and along Yellow River, take higher risk. Dynamically, the risk degree presents a downward trend from 2000 to 2008, which is due to the implementation of various measures concerning eco-environmental construction and restoration. To be specific, the risk of grass and desert ecosystems decreases significantly, so does the farmland and forest. However, the risk of water and urban and rural ecosystems increases.

Key words: regional ecological risk, conceptual model, assessment, Ordos