%0 Journal Article %A Yandong MA %A Jingbo ZHAO %A Xiaoqing LUO %A Tianjie SHAO %A Dapeng YUE %A Qi ZHOU %T Runoff and groundwater recharge conditions in the megadune area of Badain Jaran Desert %D 2016 %R 10.11821/dlxb201603007 %J Acta Geographica Sinica %P 433-448 %V 71 %N 3 %X

Field investigation was carried out in the Badain Jaran Desert, where develop numerous megadunes with the largest height difference in the world. Infiltration-excess runoff, slow seepage runoff, erosion features of runoff caused by atmospheric precipitation, as well as mixed physical sediment of runoff-aeolian sand and chemical deposition (secondary salts) caused by ground runoff converted into surface runoff, were discovered in the slope surfaces of megadunes. These natural features are rare in arid desert area. According to the data of electron microscopy observation, energy spectrum analysis, chemical analysis and particle-size analysis and others, some issues are discussed, namely, mineral and chemical composition of secondary salts, particle-size composition of aeolian sand and mixed physical sediment of runoff-aeolian sand, runoff type, water balance of megadune area and mechanism of precipitation recharging groundwater and lake water. The emergence of infiltration-excess runoff means that the strong effective precipitation can be used as a source of groundwater, although there is less rainfall in this region. Various runoff and runoff depositions on a deep level sufficiently prove that precipitation via infiltration reaches the bottom of megadune and constitutes effective recharge to groundwater. The fine layer with relative impermeability is the reason why underground runoff is exposed to Earth's surface. The positive water balance is surprising in the megadune area. Precipitation, after evaporation and transpiration, and other consumption, could provide about 134648.4 tons of water per square kilometer per year to recharge groundwater and lake water, which has become one of the important recharge sources of lake water. Positive water balance and precipitation can recharge groundwater in the megadune area and mainly depend on four conditions, namely, the presence of effective precipitation, scarce vegetation and less transpiration, a high infiltration rate and a small evaporation depth of sand layer. These factors are also the priority for numerous lakes developed in the megadune area of the Badain Jaran Desert.

%U https://www.geog.com.cn/EN/10.11821/dlxb201603007