Variation and main causes of runoff and sediment in main rivers in arid inland areas of China in recent 70 years

Abstract

The variation of water and sediment in rivers is related to the health and function of rivers, and also reflects the environmental changes in the river basins. To understand the water and sediment variation and the influence of human activities in rivers of the arid inland areas in China, the Tarim River, Heihe River, and Shule River are selected, which are representative rivers in arid inland areas of China. The cumulative curve method and the M-K test are used to systematically analyze the change characteristics of annual runoff and annual sediment transport at representative hydrological stations in these rivers from 1950 to 2020, and explores the main factors affecting the water and sediment changes in arid inland river basins. The result indicate that the annual runoff at the representative hydrological station of the Tarim River exhibits no trend variation, whereas the annual sediment discharge presents a significant decreasing trend. The annual runoff at the representative hydrological station of the Heihe River shows a significant increasing trend, while the annual sediment discharge shows a significant decreasing trend. The annual runoff at the representative hydrological station of the Shule River displays a significant increasing trend, and the annual sediment discharge shows an increasing trend. The main factors affecting the change of runoff and sediment in arid inland rivers include climate environment, reservoir construction, watershed diversion and river overflow, soil and water conservation, unreasonable exploitation and utilization of watershed, and imperfect watershed policies and management.

Keywords

Arid inland rivers / runoff and sediment load variations / trend analysis / main influencing factors / human activities