干旱区生态环境知识资源中心

This paper selects indexes such as climate inclination rate, anomaly, cumulative anomaly and 5 a moving average to study the climate change of Shiyang River from 1951 to 2005. It discusses the characteristics and laws of the variation of meteorological factors. The results show that in the past 50 years, the overall performance rainfall in the basin is a downward trend. 1962 was a turning point for the reduction of the rainfall in the upstream. But there was a significant increase in the midstream and the downstream since the 1990s. The region has a warmer temperature since 1987, 1997 and 1987 respectively for the upstream, the midstream and the downstream. The temperature surged in particular in 2000. The wind velocity in the upstream significantly increased in the 20th century. That in the midstream registered a fluctuation for every decade. 1984 marked the decrease of wind velocity in the downstream. As for the humidity, the mid-1950s to mid-1960s were the period with the most obvious reduction, while in the late 1990s, the humidity significantly reduced in the midstream. The humidity remained low between 1999 and 2005. With the construction of Shiyang River Protection Project in recent years, the drought has been eased in the midstream and the downstream and the situation is expected to improve gradually.