Ecological compensation strategies of river basin based on ecological risk assessment

Quantitative assessment of ecological risk assessment(ERA) is the basis for maintaining ecosystem health,establishing ecological compensation mechanism and ensuring sustainable development in river basins.Temporal and spatial variations in water resource directly control the environmental quality in river basins.Based on the natural condition and human disturbance,several indicators including surface water mineral level,under-ground water depth,strong wind days and sandstorm days,normalized difference vegetation index(NDVI) as well as water conservancy infrastructure were chosen for the ERA.An assessment model of ERA based on AHP integrated assessment method was developed.Results of quantitative assessment differed among different sections of the mainstream.The values of ecological risk score were 2.25,2.7,3-4.2 respectively in the upper,middle and lower reaches of Tarim River,indicating the degree of ecological risk in the upper reach of the Tarim River was lower than in the middle-and lower reach of Tarim River.Understanding the relationship between ecologi-cal risk and central issue in ecological compensation,extending the views and options of ecological compensa-tion,and developing ecological compensation mechanism are important for achieving the goal of environmental management in the basin.