Eco-environmental Quality Assessment of Ruoergai County in Sichuan Province Based on Multi-sources Remote Sensing Data
Compared with traditional methods for eco-environmental assessment, the method based on remote sensing imagery is more convenient and does not require huge amounts of statistical data. Satellite remote sens-ing has the advantages of efficient, economical, macro and dynamic monitoring of land surface and therefore is an excellent way in providing data for eco-environmental assessment. Scholars have deeply studied how to ex-tract ecological environment factors from remotely sensed data. In this paper, normalized difference vegetation index (NDVI), land surface temperature, slope, aspect, land use and wetness index were selected as evaluation factors, and the eco-environmental quality of Ruoergai County of Sichuan Province in the years of 2007, 2009 and 2012 is assessed based on multi-sources remote sensing images (TM, HJ1B CCD1/CCD2, ASTER GDEM, and MODIS) and GIS technology. Firstly, the evaluation factors were extracted from remote sensing images. Sec-ondly, based on principal component analysis (PCA) method, the weight of each factor was determined and used to calculate the eco-environmental quality index of Ruoergai County with the comprehensive index evaluation model. Thirdly, according to the eco-environmental quality index, the study area is divided into four regions that are marked with four different degrees which corresponds to excellent quality, good quality, general quality and poor quality. Finally, the spatial analysis was integrated into the eco-environmental quality assessment. The re-sult shows:(1) the global eco-environmental quality of Ruoergai County is at the level of good quality, for all of the average quality indexes of 2007, 2009 and 2012 are around 60 which represents good quality. (2) For a given year, the average and minimum values of eco-environmental quality index in September are both larger than that in May. (3) The ecological environment in the east region and middle region is better, while the northwest region is worse than others.
environment assessmenteco-environmental qualityPCARuoergai County
NETL
NSTL
万方数据
维普
