Ecological Risk Assessment Of Yunnan Honghe Based On Landscape Heterogeneity

Honghe County of Yunnan province as the study area, according to the basic principles of landscape ecology, using GIS and fragstats software, the landscape structure and landscape heterogeneity were analyzed, and on the basis of the selection of diversity index, separating degree index, fragmentation index, fractal dimension from some degree of interference based on the characterization of landscape heterogeneity and landscape vulnerable degree, determine the risk receptor, end point of ecology, ecological risk value within the research unit is calculated and its evaluation. The evaluation results can provide theory support for the ecological risk management and decision-making, the results show that:1, Honghe County of Yunnan province has got a heterogeneous composite ecosystem of patch-corridor-matrix model-forest matrix, highway, river for the corridor, cultivated land, garden land and grassland landscape group is divided into patches of matrix- patch, corridor model the heterogeneity of landscape ecological system.2, Due to the common effect of risk source like natural disasters, human activities and the differences of risk receptor,the ecological risk values in each research unit are different. In this study, 13 towns are selected as evaluation unit. And the study calculated different ecological risk values based on landscape heterogeneity which between 0.2127~0.4279. In terms of natural disasters and human activities, the ecological risk value of Jia Yin Xiang is the largest;And the the ecological risk values of Hongen Xiang, Jia Che Xiang, Yi Sa Xiang, Baohua xiang, and Sancun Xiang are basically in the same level which are between 0.29~0.30;The ecological risk value of Azha He Xiang,Langti Xiang,Dayang jie Xiang are between 0.31~0.32; And Chegu Xiang has got the minimum ecological risk value.3, Yi Sa Zhen,the location of Honghe County government of Yunnan Province,has the highest population density, where the influence of human activities has the largest effect on the ecological environment,and its ecological risk value is in the middle level of the entire study area due to the common effect of water pollution, reasonable division of functional areas and human activities. The ecological risk of Jia Yin Xiang and Yue Yu Xiang in critical dam area is highest, caused by following possible reason such as the water pollution, flood disaster, drought, frost, man-made destruction.And so on. The highest,higher,medium risky area account for 99 percent of proportion of entire research area,thus,ecological risk management tasks.4, Based on the ecological risk assessment results, we can put forward the corresponding countermeasures of ecological risk management according to the different evaluation unit and risk grade, providing guidance for the improvement of regional ecological environment and maintenance.