A remote sensing index for assessment of regional ecological changes

A remote sensing based ecological index(RSEI) was developed specially for monitoring and assessing regional ecological changes.The index combined four indicators from existing remote-sensing indices/components to represent greenness,dryness,wetness and heat,which were the important ecological indicators frequently used in assessing regional ecology.Instead of a weighted addition of the four indicators,the principal component analysis(PCA) was utilized to compress the four indicators into one in order to assess overall regional ecological status.The RSEI was then constructed using the first component(PC1).The application of RSEI in Hetian area of County Changting in Fujian Province,China,showed that the RSEI could quantitatively reveal regional ecological changes during the period from 1988 to 2010.The RSEI values could be well compared with the commonly-used ecological index(EI).Nevertheless,besides working as a quantitative indicator,the RSEI had more functions than the EI,such as detecting,simulating and predicting spatiotemporal changes of regional ecological quality.