海底泉对在海底有限延伸的越流含水层系统中地下水潮汐效应的增强作用

Modelling Tidal Signals Enhanced by a Submarine Spring in a Coastal Sonfined Aquifer Extending under the Sea Finitely

海底泉在滨海地下水排泄过程中起着重要的作用。本文给出了含有一个海底泉的在海底延伸的越流承压含水层系统中地下水水头在海潮作用下波动的近似解析解。该含水层顶底板隔水且向海底延伸有限距离。假设含水层的海底露头被一层隔水层覆盖,海底泉由一个渗透性很好的完全穿透海底含水层顶板的圆柱体渗漏天窗(海底泉孔)来表示。近似解析解中包含了6个参数:承压含水层的海潮传播参数,海底泉孔中心到海岸线的距离,表示泉的圆柱体的等效半径,海底泉孔中心到含水层海底露头处的距离,承压含水层的海潮载荷效率和弱透水层的越流。分析表明,如果海底泉孔中心到海岸线的距离远大于泉孔的等效半径,且海底泉孔中心到含水层海底露头处的距离远大于泉孔的等效半径时,解析解的近似误差可以忽略。然后本文讨论了解析解的两个基本性质,分析了海底泉对海底地下水水头波动的影响。

Submarine springs play an important role in the submarine groundwater discharge of a coastal aquifer system, This paper presents an approximate analytical solution of tidal head fluctuations in a leaky confined aquifer extending under the sea with one submarine spring. The confined coastal aquifer extends under the sea for some distance, and to be overlain by an impermeable layer. The spring is represented by a permeable round column on the seabed, which penetrates completely the impermeable layer overlying the confined aquifer. The solution have 6 parameters： the confined aquifer＇s tidal propagation parameter , the distance from the centre of the spring hole to the coastline , the radius of the permeable column representing the spring , the distance from the centre of the spring hole to the submarine outlet , the tidal loading efficiencies of the confined aquifer and the leakage of semi - permeable layer, The two errors of the approximate solution are negligible if both the distance from the spring to the coastline and the distance from the spring to the submarine outcrop are much greater than the radius of the permeable column representing the spring. Then we discuss two basic properties of the approximate solution, and analyze the effect of head fluctuation of submarine groundwater by the submarine spring.