干旱区生态环境知识资源中心

Changes in the hydrologic characters of the Tarim River Basin of Xinjiang Province during the past 50 years were studied to identify the key factors responsible for these changes. Observed hydrologic and socio-economic data provided the basis for this study. The impact of human activities on the decrease in the streamflow and changes in total dissolved solids (TDS) in the watercourse and groundwater of the mainstream were analyzed using the Mann-Kendall test, regression and principal component analysis. The results showed that during the past 50 years the streamflow in the headwater streams has increased slightly while the streamflow in the mainstream has decreased significantly. Human activities along the mainstream are the primary reason for the decreased streamflow, with the impact of human activities on the decrease in the streamflow of the mainstream being 65.61, 74.73 and 77.62% in the 1970s, 1980s and 1990s, respectively. The key factor that affected the TDS of the watercourse was the decreasing streamflow, which was caused by anthropological activities. However, the TDS of the groundwater was found to be affected significantly by groundwater depth. The degeneration of ecosystems in the lower reaches of the Tarim River was directly related with anthropogenic activities.