GroMoPo Metadata for SW Bangladesh stream-aquifer-coastal model

A numerical model for simulation of the regional flow and salt-water intrustion in an integrated stream-aquifer system in coastal regions is developed, considering the dynamic interaction between the streams and the aquifer, The stream-aquifer model comprised of a two-dimensional depth-average finite-element model of the aquifer system and a quasi-steady node and reach model of the river network. The applicability of the model was demonstrated, through simulation of the spatial and temporal distributions of flow and salinity in the estuaries and in the underlying aquifer of the Southwest Region of Bangladesh. The important management aspects of water transfer and additional pumping and their effects on the system were evaluated. The interactions between the streams and the aquifer significantly influenced the flow and salt-water intrusion in the aquifer and the river network. An increased abstraction of ground water in the area caused a significant increase in the estuarine salinity. The salinity intrusion in the estuaries of the area, except in the southwest corner, could be reduced significantly by diverting the available water from the Ganges through the boundary river Gorai.

本研究针对沿海地区一体化河流-含水层系统（integrated stream-aquifer system），构建了用于模拟区域水流与盐水入侵（salt-water intrusion）的数值模型，同时考量了河流与含水层间的动态相互作用。该河流-含水层模型由含水层系统的二维深度平均有限元模型以及河网的准稳态节点-河段模型组成。通过模拟孟加拉国西南部地区河口及下伏含水层中水流与盐度的时空分布，验证了该模型的适用性。本研究还评估了调水、新增抽水等关键水资源管理措施及其对该系统的影响。河流与含水层间的相互作用，对含水层及河网内的水流与盐水入侵过程具有显著影响。该区域地下水开采量的增加，会导致河口盐度显著升高。通过将恒河（Ganges）的可用水量经界河戈赖河（Gorai）调水，可显著降低该区域除西南角外的河口盐水入侵程度。