Evaluation Of Ecological Situation At The County Level Based On The "3S" Technologies

In order to compare the ecological situation between different geographical districts and counties of our country at the same level,this paper used "3S" technologies,AHP(analytic hierarchy process) and Principal Component Analysis to study,using ERDAS,ARCGIS,PCI applications as the basic tools for data analysising.By selecting the appropriate ecological indicators that can reflect the ecological situation of the study area,this study built evaluation index system and evaluation model of ecological situation at the county level,which adapted to different geographical units,and according to the model,we divided ecological situation into five grades:excellent,good,medium,poor,worst,which can reflect different ecological situation and having different Ecological significance.By appling two anslysis methods to four pilot districts,Tieling Country in Liaoning Province, Wuqing district in Tianjin,Yanchi County in Ningxia Hui Autonomous Region and Yiling in Hubei Province,which indicated that the whole ecological situation of Yiling is better than Tieling's whose is better than Wuqing's and the worst is Yanchi's,which reflected the basic ecological situation of the pilot districts.By qualitativing the indicators,the study resolved a horizontal comparison issues of ecological situation among different geographic units and filled a vacancy of the assessment of ecological conditions,which is of great significance in promoting the database construction of the ecological situation at the county level in China,but also provided basic data for the dynamic monitoring of ecological situations in different districts and counties.