Different climate factors contributing for runoff increases in the high glacierized tributaries of Tarim River Basin, China

Abstract

Study region: The headwaters of Tarim River. Study focus: The Tarim River basin is the largest arid inland river basin in China and recently only Aksu, Yarkant and Hotan Rivers have natural hydraulic connections with it. With climate changing, the runoff from the headwaters of Tarim River basin has undergone obvious changes that significantly affected downstream areas. It is necessary to quantitatively attribute the impact of climate changes on runoff. However, the previous researches mostly focused on the Aksu River basin, and the attribution of runoff changes in the Yarkant and Hotan River basins was nearly blank. This paper is dedicated to reveal the dominated climate factors for the runoff changes in all the three tributaries with large glacier coverage, by combining the glacier-enhanced SWAT model with the original and detrended precipitation and temperature inputs. New hydrological insights for the region: It was recognized that the rising temperature respectively contributed 94 % and 66 % to streamflow increases in the Hotan and Aksu River basins with slower glacier shrinking during 1965−2007. Meanwhile, the increased precipitation contributed 87 % to streamflow increase in the Yarkant River basin with a larger glacier area retreating ratio. It is not as widely believed that the runoff changes in high glacierized basins are more correlated with temperature changes. The respective variation amplitude of temperature and precipitation should be concerned in every catchment.

Keywords

• Climate change
• Serial correlation
• Streamflow changes
• Variance correction approach
• Tarim River basin