澜沧江上游河谷卸荷松弛区地下水位分布成因  

Causes of Groundwater Level Distribution in the Unloading Relaxation Area of the Upper Lancang River Valley,China

作　　者：黄瑞瑞 王锦国[1] 程伟 韩智颖 尤琳 杨蕴[1] 朱淳 HUANG Rui-rui;WANG Jin-guo;CHENG Wei;HAN Zhi-ying;YOU Lin;YANG Yun;ZHU Chun(School of Earth Sciences and Engineering,Hohai University,Nanjing 211100,Jiangsu,China;Kunming Engineering Corporation Limited,PowerChina,Kunming 650051,Yunnan,China)

机构地区：[1]河海大学地球科学与工程学院,江苏南京211100 [2]中国电建集团昆明勘测设计研究院有限公司,云南昆明650051

出　　处：《地球科学与环境学报》2023年第6期1414-1426,共13页Journal of Earth Sciences and Environment

基　　金：云南省重大科技专项计划项目(202002AF080003);国家重点研发计划项目(2019YFC1510802)。

摘　　要：澜沧江上游两岸山体普遍存在强卸荷松弛和地下水位低缓现象,深入研究岸坡卸荷松弛区水文地质特性可为开展水电工程运行期渗流特征分析和渗控设计提供依据。澜沧江深切河谷区地下水位低缓成因复杂,选取上游某水电站坝址区为研究对象,从区域条件和局部条件综合分析地下水位低缓的原因,构建研究区考虑卸荷松弛分带的水文地质结构和地下水流模型,模拟与验证自然条件下地下水渗流规律。结果表明:研究区地下水位低缓既受控于区域地下水流与澜沧江的共同作用,又是河谷岸坡坡度、表层滑带、岩层结构、卸荷裂隙等局部水文地质条件阻碍降雨入渗补给地下水的内部表现;降雨径流受地形控制,主要经地表及强卸荷裂隙排泄至澜沧江,降雨入渗补给仅占地下水总补给量的5.50%。The phenomena of strong unloading relaxation and low groundwater level are common on both sides of the upper Lancang River.In-depth study on hydrogeological characteristics of slope unloading relaxation area can provide a basis for seepage characteristics analysis and seepage control design of hydropower projects during operation.The causes of low groundwater level in the deep-cut valley of Lancang River are complex.A hydropower dam site in the upper Lancang River was selected as the research object;the causes of low groundwater level from regional and local conditions were analyzed;and the hydrogeological structure and groundwater flow models were finally constructed for the dam site area,considering the unloading relaxation partition to simulate and verify the groundwater seepage law under natural conditions.The results show that the low groundwater level in the study area is not only controlled by the joint action of regional groundwater flow and Lancang River,but also an internal manifestation of local hydrogeological conditions,such as bank slope,surface slip zone,rock structure and unloading fissure,which hinder the rainfall infiltration;the rainfall runoff is controlled by the topography,and is mainly discharged to Lancang River through the surface and strong unloading fissures,and the rainfall infiltration recharge only accounts for 5.50%of the total groundwater recharge.

关 键 词：水文地质 地下水位 数值模拟 卸荷松弛 水均衡 非均质性 各向异性 澜沧江 

分 类 号：P641.6[天文地球—地质矿产勘探]