Assessment of the eco-environmental quality in the Nanweng River Nature Reserve, Northeast China by remote sensing.

Scientific and rapid assessment of the ecological environment quality based on remote sensing can provide basis for regional protection, management and planning. In this study, using Landsat TM/OLI/TIRS in 1990, 2000 and 2015 as data sources, four indices including the wetness component of the tasseled cap transformation (WET), normalized difference vegetation index (NDVI), normalized difference built-up and soil index (NDSI), and land surface temperature (LST) were derived, with the weights being determined by principal components analysis (PCA). Remote sensing ecological index (RSEI) was used to evaluate the eco-environmental quality of Nanweng River Nature Reserve from 1990 to 2015. Results showed that RSEI was an effective indicator for evaluating spatio-temporal dynamics of eco-environmental quality. From 1990 to 2015, the mean value of RSEI of Nanweng River Nature Reserve increased from 0.55 to 0.83, the proportion of area with excellent and good levels of RSEI trended to increase, probably due to the increase of forests at those levels. Meanwhile, 91.4% of the total land area in the reserve had an improved eco-environmental quality. Such improvement was attributed to the establishment of the reserve and implement of a series of engineering and non-engineering protection measures. In the north of core area and buffer area, decrease of eco-environmental quality was due to forest fires which destroyed a large area of forest vegetation. In the road side and southeast of the experimental area, intensified human activities led to the decrease of regional eco-environmental quality.