乌兰布和沙漠降水入渗补给对气候变化的响应

Rainfall Infiltration Recharge and Its Responses to Climate Change in the Ulan Buh Desert

为探究地下水补给对气候变化的响应,以乌兰布和沙漠为例,基于氯质量平衡法,通过野外打钻和室内离子分析,重建区域地下水补给历史和短时间尺度的气候变化过程。结果表明:降水对沙漠地区的地下水补给非常小,对比周边地区记录发现,地下水补给呈现出由西向东逐渐增大的趋势,且一定程度上反映出贺兰山对季风气流的阻挡作用,在相关季风较弱年份,贺兰山西侧降水补给弱于东侧。过去600年来本地区的气候波动大,1455—1500AD、1600—1650AD是气候较为干旱的时期,18世纪末至19世纪初是环境演化一个重要的时间界限,自此以后的漫长时间,干旱化进程进一步加剧,尤其是1920—1930AD,区域极端干旱。本研究也验证了处于季风边缘沙漠地区降水入渗补给对气候变化所呈现出的响应差异。

To explore the response of groundwater recharge to climate change,this study takes Ulan Buh Desert as example and reconstructs the history of regional groundwater recharge and the process of climate change in short time scale based on chloride mass balance method through field drilling and ionic analysis.Results show that the groundwater recharge from precipitation was a very small extent.Compared with other records of the surrounding area,it was founded out that groundwater recharge gradually increased from west to east,which reflectd Helan Mountain＇s blockage against monsoonal airflow to a certain degree.In years of relatively weak monsoon,rainfall recharge in the west side of Helan Mountain was weaker than that on the east side.Climate fluctuated dramatically over the last 600 years,the periods of 1455-1500 AD,1600-1650 AD were relatively arid and the period from the late 18 th century to the early19 th century was an important time range of environmental evolution.Over a long time since then,the process of aridification further intensified,especially during the period of 1920-1930 AD,the region was extremely arid.This study also examined the differences between rainfall infiltration recharge and its responses to climate change in monsoon marginal belt of desert areas.