滨海深部含水层地下水排泄量评估

Estimation on submarine groundwater discharge through deep confined aquifer system extending under the sea

为了进一步计算评估滨海深部含水层地下水排泄量,以一个海底深部承压含水层系统为例,包括承压含水层及上覆弱透水含水层（海底）,在内陆补给上考虑了与时间无关的年平均补给（常数）和由季节性降雨引起的周期性补给两种情况,从而建立了一个描述承压含水层中海底地下水排泄的数学模型,并得到其解析解。继而利用解析解分析了位于美国南大西洋Onslow海湾的SGD。结果显示,SGD排泄宽度变化范围为0.5-3.0 km,在承压含水层中海岸线处高于平均海平面1.0 m的水头值,其所产生的SGD速率为1.1-10.0 m^2/d。

There is great uncertainty in estimating the percentage of net inland groundwater recharge in submarine groundwater discharge（SGD）.Moreover,most of the previous studies only consider the recharge of coastal superficial homogeneous aquifers.We established a model to investigate the SGD through deep submarine aquifer system composed of a confined aquifer and a semi-permeable layer（seabed）.The inland recharge includes a constant quantity（annual average） and a periodical quantity caused by seasonal rainfall.Analytical solution is derived and used to analyze the distribution of the SGD along the Onslow Bay transect,South Atlantic Bight in America.It is found that the width of the zone of SGD from the aquifer ranges from about 0.5 km to about 3.0 km.1.0 m water head in confined aquifer at coastal line（to the mean sea level） will cause a SGD rate of 1.1 m2/d - 10.0 m^2/d.