Ecological risk evaluation based on GIS and spatial geo-statistics method

Ecological Risk (ER) refers to the possibility of reduction for its partial health, productivity, economic value and aesthetic value when normal functions of whole landscape have been intimidated by external environment. Ecological risk assessment is a key measure of ecological environment management. Assessing the ecological risk at regional scale has practical significance in strengthening ecosystem management and regional ecological safety. In this paper, the main land use information comes from satellite remote sensing TM image in 2000 and 2005, GIS technology is the data integration analysis platform, and Wuhan city was selected for a case study. This article analyzed the landscape ecological characteristics of Wuhan, based on the landscape structure, the authors brought forward indexes and formulas to measure landscape damage degree and risk value of ecosystem. The system sampling method was used to make it a spatial variance, and the semi-variagram analysis and block Kriging were conducted to explore the spatial characteristics and distribution of landscape ecological risk in the study area. The results indicated that the ecological risk in the study area tends to extend and three belt areas with high ecological risk were formed in this region. The spatial distribution of ecological risk becomes more uneven. The level of ecological risk study area is divided into three levels: the majority of the vegetation and the waters belong to low ecological risk, urban built-up area and near the edge belong to moderate ecological risk and relatively high risk region. Spatial distribution areas of the various levels have taken place in a certain degree of change in 5 years.