Hydrological interactions between oases and water vapor transportation in the Tarim Basin, northwestern China

Abstract

The spatial evolution of the oasis cold-wet effects in Tarim Basin, northwestern China, are explored quantitatively by using the China Meteorological Forcing Dataset, with spatial and temporal resolution of 0.1 degree and 3 hours, respectively, and the hydrological interactions between the oases and water vapor transfer are discussed to uncover the influence of oases on regional precipitation. The results reveal that the annual precipitation exhibits an increasing trend from desert toward oasis at all four oases. However, the cold effect is not the dominating factor increasing precipitation, since the maximum increasing rate of precipitation is accompanied by the minimum decreasing rate of temperature. Indeed, water vapor transportation is more important than the cold effect. The maximum promotion of precipitation is observed in western basin, where the water vapor transfer follows the gradients of decreasing temperature and increasing humidity. Conversely, the minimum promotion in southwestern basin results from water vapor transportation following the temperature increasing. Therefore, the transfer of water vapor and its interactions with local surface conditions determine the precipitation in oasis areas. Understanding these processes is crucial to exploring the formation and spatial layout of oases, which is helpful for preventing desertification and protecting the fragile oasis ecosystem.