Regional Optimizing Management on Degraded Grassland based on Ecological Risk Assessment Xiaohe Gu, Chunyang He, Mingchuan Yang†, Yaozhong Pan, Xiaobing Li , Peijun Shi Key Laboratory of Environmental Change and Natural Disaster of Ministry of Education of China College of Resources Science & Technology, Beijing Normal University Beijing, China, 100875. †Corresponding author, e-mail: yangmc@ires.cn Abstract—In order to replenish the current few researches on degraded grassland management, this paper develops an ecological management index (EMI) of degraded grassland, which integrates the information of degradation degree, risk degree and easily-restoration degree by spatial analysis of remote sensing (RS) and geography information system (GIS), in the context of ecological risk assessment. Specially, it estimates EMI of degraded grassland at Xilin River Basin, Inner Mongolia, China and proposes relative measures to restore the degraded grasslands at different EMI level. The case study demonstrates that the EMI can synthesize the degradation level, hazard and the restoration benefit of degraded grassland, which is significant for the optimum allocation of resources during the restoration of degraded grassland. In addition, the EMI is universal to the assessment of degraded grassland in most regions in that it can integrate most concerned information. Keywords-degraded grassland; EMI; risk degree; easily- restoration degree; degraded degree I. INTRODUCTION The grassland degradation is one of main manifestation of desertification. The term “grassland degradation” often refers to a process in which grassland production decreases and ecosystem condition deteriorates because of poor management, overgrazing and changing physical environments (Li et al., 1988). The ecological crisis derived from grassland degradation, not only restricts the stockbreeding to develop healthily, but also sharpens the contradiction between ecological environment and social economy. In order to resolve the problem of global grassland degradation, many scholars and experts have carried out plenty of valuable researches on grassland management. Gudrun A.I. Berlin et al (2000) pointed out that stable grassland management contributes to sustain the stability of landscape and protect the species of grassland. A number of local-scale studies of the grassland degradation in Inner Mongolia have been done (e.g. Bao and Chen, 1994; Wang et al., 1996). Li et al (2000) analyzed the influence of grazing and microclimate, and pointed out that overgrazing was the main factor of grassland degradation in Inner Mongolia, China. In recent years, based on remote sensing technology, Tong et al have done a series of studies on the grassland degradation in Xilin River Basin, Inner Mongolia, China, developed a steppe degradation index (SDI) that integrates the information on the spatial extent and severity of steppe degradation. These current studies emphasize particularly on analyzing the cause and management policy, but lack the quantitative study on optimizing management of degraded grassland and the study of grassland management index. Grassland degradation is caused by many factors, so optimizing management on grassland degradation must base on quantitative and comprehensive risk analysis. Allen (1995) pointed out that, according to the recent environmental indicator research, the conformity of environment indicator is an important trend. Therefore, it is necessary to evaluate quantificationally the comprehensive risk of degraded grassland in different conditions, develop comprehensive evaluation indexes, establish scientific managing measures, and achieve optimum management by limited resource. In 1990s, America scientists, Joshua Lipton et al, developed a standard frame of ecological risk evaluation, which had been accepted widely. In order to supply theory and technology for regional risk management, regional ecological risk evaluation describes and evaluates the possibility and distribution of the disadvantage of ecosystem, which caused by environmental pollution, human impacts and natural disasters. In order to replenish the current few researches on degraded grassland management, this paper develops an ecological management index (EMI) of degraded grassland, which integrates the information of degradation degree, risk degree and easily- restoring degree by spatial analysis of remote sensing (RS) and geography information system (GIS), in the context of ecological risk assessment. Specially, it estimates EMI of degraded grassland at Xilin River Basin, Inner Mongolia, China and proposes relative measures to restore the degraded grasslands at different EMI level. II. THE ECOLOGICAL OPTIMIZING MANAGEMENT MODEL OF REGIONAL DEGRADED GRASSLAND BASED ON ECOLOGICAL RISK EVALUATION The ecological risk evaluation involves hazard assessment, exposure assessment, receptor assessment and risk characterization. In order to distribute resource effectively in the management of degraded grassland, this paper introduces the idea of ecological risk evaluation, develops ecological management index (EMI) by integrating the information of degradation degree, risk degree and easily-restoration degree of This work was supported by the National Natural Science Foundation of China (Grant No. 40371001) 0-7803-9051-2/05/$20.00 (C) 2005 IEEE