Precipitation, Runoff, and Evaporation Trends in Northwest China over the Past 40 Years

Abstract：

Understanding of the trends of water resources in the arid region of northwest China (NWC) is essential for effective flood control, scientific management of water resources, protection of the ecological environment, reasonable irrigation, and navigation in China. Herein hydrological trends in NWC were analyzed based on total precipitation, evaporation, and runoff using climate trend rate method. Then Mann-Kendall sequential test was employed to carry out the detection of trend significance, and the future trend was calculated employing R/S analysis method (Rescaling range analysis). The results indicated that a significant change was observed in 2004 for precipitation, evaporation, and runoff so that an increasing trend was more pronounced after 2004 in comparison with the results obtained between 1979 to 2004. Additionally, most water resources concentrated in a small part of the southwestern border of NWC. Since runoff represented good correlation with precipitation and evaporation, regression analysis can be used to establish a runoff prediction model to forecast future runoff.

Key words:

Precipitation; Evaporation; Runoff; Northwest China; Spatial Distribution; Temporal Tendency