Precipitation Recycling in Tarim River Basin: Fid-Bau Portal

Precipitation Recycling in Tarim River Basin

Hai, H. E. / Guihua, L. U.

Precipitation recycling plays a key role in the hydrological cycle process. The precipitation recycling ratio is a diagnostic measure for interactions between land surface hydrology and regional climate. To demonstrate the influence of the hydrological cycle on the climate of an arid area in northwest China, the authors studied the precipitation recycling ratio and the characteristics of the hydrological cycle in the Tarim River basin, which includes characteristics of water vapor transportation flux divergence and convergence, evaporation and its spatial distribution, and the spatial distribution of precipitation recycling ratio. The results suggest that there is about 14% of annual precipitation coming from the evaporation of the Tarim River basin, and 86% of advected precipitation coming from the surrounding external areas to the region. It is lower than other world famous river basins such as the Amazon, the Mississippi River, the Yellow River, and the Yangtze River basins. The recycling is active over the region during the months from April to July, and extremely inactive during the months from October to next January. The recycling ratio is relatively high in the northwest and north area where human beings live and open up large tracts of wasteland for cultivation and then change the land surface, which acts as a significant source of moisture to the atmosphere during certain seasons. Analysis of the recycling ratios spatial distribution suggests that the basin’s unique topography and land surface use change (through evapotranspiration) have influenced the precipitation and its recycling over the basin.