Dynamic monitoring of eco-environment quality changes based on PCA:A case study of urban area of Baoji City

Using remote sensing method to study eco-environment quality changes is immediate and rapid. Based on remote sensing image and principle component analysis, the authors combined vegetation index, wet index, dryness index and temperature index to evaluate the eco-environment quality of Baoji City and the land-use types from 2002 to 2013. The results indicate that the ecological construction work has made remarkable achievements in the past 10 years. The area of improved eco-environment quality reached 39.50%, while the area of degraded quality possessed only 10.96%;in addition,synthetical ecological index(ESI) increased from 3.25 to 3.56. The eco-environment quality of Chencang District and Weibin District was improved while that of Jintai District was degraded. The ESI of land - use types from high to low is forest land, unexploited land, grassland, waters, cultivated land and construction land. RSEI degree of cultivated land has no significant change,that of forest land, grassland and unexploited land have been improved while water and construction land have been degraded.