北京平原区单次降水对地下水位影响的初步认识——以北京“7·21”特大暴雨为例  

Impact of Individual Rainfall Event on Groundwater Levels in Beijing Plain: Taking “7·21 Heavy Rain” as Study Case

作　　者：刘元章[1] 武强[2] 邢立亭[3] 林沛[1] 韩征[1] 雷坤超[1] 

机构地区：[1]北京市水文地质工程地质大队,北京100195 [2]中国矿业大学(北京)水害防治与水资源研究所,北京100083 [3]济南大学资源与环境学院,山东济南250022

出　　处：《水文》2013年第6期42-46,共5页Journal of China Hydrology

基　　金：北京市平原区地下水污染调查项目(PXM2009-158305-074498)

摘　　要：通过对北京市平原区600余眼监测井水位动态资料的分析,2012年北京"7·21"特大暴雨后水位有明显响应的监测井仅有34处,约占总数的6%左右,比例较低,同时范围较为集中,且基本全为较浅的潜水井。反映出本次大暴雨对本区地下水位的直接影响总体程度不深。通过对这些监测点的分布规律加以分析,它们主要集中分布在各大河的上游河道沿线区域,地层渗透性较好。并认为发生大面积的漫水,即来水量较大是使得地下水位响应明显的另一重要条件。并对单次降水对水位影响较小的原因进行了分析,认为主要是由于粘土类地层的阻隔、地表人为硬化及地层的沉积压实,尤其是差异性压实,都会影响流场的畅通性,阻碍地下水的垂向入渗及水平方向的补给,从而会导致降水对地下水位的影响程度被大大减弱。The analysis of the groundwater levels of more than 600 monitoring wells in Beijing Plain shows that 34 monitoring wells have an obvious response to the heavy rain occurred on 21 July, 2012, accounting for about 6% of the total. According to analysis of the 34 monitoring wells, most of them are located along the upstream channels of the big rivers where the permeability of strata is much better. It holds that an occurrence of diffuse water of a large area, that is another important factor for an obvious response of the groundwater levels. It also gives an analysis of the reasons of the small influence of the single rainfall, and holds that the blocking effects of the clay type strata, surface hardening and the compaction of the strata during the sedimentary process, especially the differential compaction, are the main reasons. Because these all could weaken the permeability both in vertical and horizontal, the impact of the rainfall on groundwater level would be greatly reduced.

关 键 词：北京平原 北京“7·21”特大暴雨 地下水位 影响程度 粘土类地层 

分 类 号：P641.12[天文地球—地质矿产勘探]