Observation of mega-dune evaporation after various rain events in the hinterland of Badain Jaran Desert, China  

作　　者：Ning Ma Naiang Wang Liqiang Zhao Zhenyu Zhang Chunyu Dong Shiping Shen 

机构地区：[1]College of Environmental and Earth Sciences, Center for Hydrological Cycle and Climate Change in Arid Region,Lanzhou University

出　　处：《Chinese Science Bulletin》2014年第2期162-170,共9页

基　　金：supported by the National Natural Science Foundation of China(41371114);the Public Industry Scientific Research Foundation of Ministry of Environmental Protection of China(201209034);the National Basic Science Talents Foundation of China(J1210065);Higher Specialized Research Foundation for Doctoral Program(20100211120006)

摘　　要：The formation mechanisms of the mega-dunes and lakes in the hinterland of Badain Jaran Desert,China,is the focus of extensive academic research in the field of geoscience,and an often debated topic is whether atmospheric precipitation on the mega-dune can infiltrate to recharge groundwater.In the present study,the probability distribution functions and the return period analysis of extreme daily precipitation based on long-term precipitation records for the southern margin of Badain Jaran Desert and 2-year observation of hinterland precipitation were used to classify precipitation in the desert region.The data of automatic weather station and eddy covariance system in the desert hinterland were used to analyze evaporation on the mega-dune surface after various rain events.The results showed that the rain events in the desert could be divided into three categories.The first is conventional precipitation(CP),which is below 5 mm,accounting for roughly 90%of all rain events in the desert.The second and third categories are ordinary annual maximum(OAM)and extreme precipitation(EP),in which precipitation is roughly 20 mm and more than 40 mm,respectively.The atmospheric precipitation of CP and OAM evaporated from the megadune surface in 1–3 days and 3–4 weeks,respectively.Following an EP event,the mega-dune evaporation was negatively influenced by the upper dry sand layer,and a lengthy period was required for its complete removal.The accumulative evaporation and accumulative precipitation of all three types of rain events indicated that local atmospheric precipitation had no significant contribution to recharging the groundwater system in the hinterland of Badain Jaran Desert.This research will benefit comprehensive elucidation of the formation mechanism of lakes in the hinterland of Badain Jaran Desert.The formation mechanisms of the mega-dunes and lakes in the hinterland of Badain Jaran Desert, China, is the focus of extensive academic research in the field of geoscience, and an often debated topic is whether atmospheric precipitation on the mega-dune can infiltrate to recharge groundwater. In the present study, the probability distribution functions and the return period analysis of extreme daily precipitation based on long-term precipita- tion records for the southern margin of Badain Jaran Desert and 2-year observation of hinterland precipitation were used to classify precipitation in the desert region. The data of automatic weather station and eddy covariance system in the desert hinterland were used to analyze evaporation on the mega-dune surface after various rain events. The results showed that the rain events in the desert could be divided into three categories. The first is conventional precipitation （CP）, which is below 5 mm, accounting for roughly 90 % of all rain events in the desert. The second and third cat- egories are ordinary annual maximum （OAM） and extreme precipitation （EP）, in which precipitation is roughly 20 mm and more than 40 ram, respectively. The atmospheric precipitation of CP and OAM evaporated from the mega- dune surface in 1-3 days and 3-4 weeks, respectively. Following an EP event, the mega-dune evaporation was negatively influenced by the upper dry sand layer, and a lengthy period was required for its complete removal. The accumulative evaporation and accumulative precipitation of all three types of rain events indicated that local atmospheric precipitation had no significant contribution to recharging the groundwater system in the hinterland of Badain Jaran Desert. This research will benefit compre- hensive elucidation of the formation mechanism of lakes in the hinterland of Badain Jaran Desert.

关 键 词：巴丹吉林沙漠 沙漠腹地 表面蒸发 沙丘 事件 降雨 巨型 中国 

分 类 号：P426.2[天文地球—大气科学及气象学]