基于耦合模型的沙颍河流域地下水与地表水硝酸盐通量过程模拟  

Modeling of nitrate flux between groundwater and surface water based on a coupled model in Shaying River Basin

作　　者：陈志慧 阮晓红 单楠 Chen Zhihui Ruan Xiaohong Shan Nan(Department of Water Sciences,School of Earth Sciences and Engineering Nanjing University, Nanjing, 210023, China)

机构地区：[1]南京大学地球科学与工程学院水科学系,南京210023

出　　处：《南京大学学报（自然科学版）》2017年第5期860-870,共11页Journal of Nanjing University（Natural Science）

基　　金：国家水体污染控制与治理科技重大专项(2012ZX07204-003)

摘　　要：为定量解析沙颍河流域地下水与地表水硝酸盐通量过程,构建了SWAT,MODFLOW和MT3DMS耦合模型,利用2007-2012年水量水质观测数据对模型进行了校验.校验结果表明,地表水流量决定系数R^2大于0.68,地下水水位和地表水水质R^2均大于0.9,地下水水质相对误差Re在15%以内,符合模型精度要求.在此基础上,选择沙颍河流域探究了流域地表水与地下水补排关系和硝酸盐通量过程.结果表明,沙颍河流域地表水与地下水的补排关系主要表现为地下水补给地表水,年均净补给水量约3.18×10~8 m^3.年际表现为丰水年大,达15.2×10~8 m^3,枯水年小,仅为0.26×10~8 m^3;年内表现为汛期地表水补给地下水,枯期地下水补给地表水;空间上表现为流域中上游(沙河、颍河中上游和汾泉河)地区大,年均值可达2.53×10~8 m^3.流域地下水对地表水年均硝酸盐净补给量0.38万吨,表现为,年内秋冬季净贡献量大,占总净贡献量的81.6%;空间上表现为流域上游地区净贡献量大,占总净贡献量的87.4%.流域中下游地区净贡献量小,占总净贡献量的12.6%.In order to quantitatively analyze the nitrate flux process between groundwater and surface water in Shaying River Basin,the coupled model of SWAT,MODFLOW and MT3 DMS was constructed.The model was calibrated and verified by the observation data of water quantity and water quality during 2007-2012.The results show that coefficients of the surface water flow,surface water quality and groundwater levels are greater than 0.68,0.9 and 0.9 respectively,and the coefficient of determination for groundwater quality is within 15%,which meet the requirements of model accuracy.On this basis,relationship of recharge and discharge,as well as nitrate flux process betweensurface water and groundwater was explored in Shaying River Basin.The results indicate that groundwater mainly recharges surface water in the research area.The average annual net water recharge is about 318 million m^3.The annual water flux in wet years is large,which can reach 1.52 billion m^3,and in dry years is small with an annual average value of 0.026 billion m^3.Generally,surface water recharges groundwater in the flood season,and the other way around in the dry season.For the upper and middle regions（Sha River,middle of Ying River and Fenquan River watershed）,the average annual value is large,which can be up to 253 million m^3.The average annual net nitrate recharge is 3800 tons.Nitrate flux from groundwater to surface water can account for 81.6% of total nitrate flux in autumn and winter.In the space,the net nitrate flux from groundwater to surface water of the upper reaches of the basin is large,accounting for 87.4% of the total net nitrate flux.The net nitrate flux in the middle and lower reaches is small,accounting for 12.6% of the total net nitrate flux of the basin.

关 键 词：地表地下水模型 沙颍河流域 地下水 地表水 硝酸盐 

分 类 号：P641.2[天文地球—地质矿产勘探]