Evaluation of the Ecological Security in Shiyang River Basin Based on Grid GIS and PSR Model

摘要

With the support of GIS technology, in this paper, each index in the evaluation system was set to the spatial expression of 100m× 100m grid scale. Subsequently, the spatial principal component analysis and hierarchy process-combination weighting method were used to express the spatial distribution of regional ecology security in study area. Some results show that:(1)The spatial distribution differences of regional ecology security are very obvious. (2)The maximum of SESI is 87.14 in Liangzhou District and its surroundings. Comparatively, the minimum value is 43.96 in north Minqin and edge of Tengery desert. This weakens interaction on ecological flowing in the basin as well as the capacity of ecological restoration between landscape patches. So the polarization of the watershed ecological security will become more seriously. (3)The ecological security and sustainable development of Shiyang River Basin are still in class of III(Threaten security)and class IV(insecurity).