Long-term trends in climate and hydrology in Jinghe River Basin

Abstract

The Jinghe River Basin lies in the centre of the Loess Plateau in China which is located in the subtropical climate zone. The watershed suffers serious soil erosion, as well as droughts. It is one of the regions with the most severe soil erosion and the most vulnerable ecological environment not only in China but also in the whole world. Linear regression analysis, Mann-Kendall trends and breakpoint analysis were used to detect the changing dynamics of climatic variables and runoff in the basin. The result shows that the temperature and precipitation in the Jinghe River basin have a uniform spatial distribution from 1960 to 2005, and the mean average temperature has shown a significant upward tendency over the years. The average annual rainfall is relatively stable, showing a decreasing trend since the 1970s. Annual runoff over 1973-2003 was a decline with a breakpoint occurred in the 1990s. Understanding the long-term trend in climate and hydrology are crucial for water resource management in semi-arid regions such as the Loess Plateau.