Department of Water Resources and River Research, Korea Institute of Civil Engineering and Building Technology, Goyang, 10223, Republic of Korea.
Civil and Environmental Engineering Department, University of Science and Technology, Daejeon, 34113, Republic of Korea.
Sci Rep. 2022 Jul 22;12(1):12520. doi: 10.1038/s41598-022-16134-1.
Identifying regional-scale surface water-groundwater interactions (SGI) is vital for predicting anthropogenic effects on surface water bodies and underlying aquifers. However, large-scale water and nutrient flux studies rely on surface water or groundwater-focused models. This study aims to model the effect of urbanization, which is usually accompanied by high groundwater abstraction and surface water pollution, particularly in the developing world, on a regional-scale SGI and nitrate loading. In the study area, the urban expansion increased by over 3% in the last decade. The integrated SWAT-MODFLOW model, Soil and Water Assessment Tool (SWAT) and Modular Finite-Difference Groundwater Flow (MODFLOW) coupling code, was used to assess SGI. By coupling SWAT-MODFLOW with Reactive Transport in 3-Dimensions, the nutrient loading to the river from point and non-point sources was also modeled. Basin average annual results show that groundwater discharge declined with increasing groundwater abstraction and increased with Land use/Land cover (LULC) changes. Groundwater recharge decreased significantly in the Belge season (February to May), and the river seepage and groundwater discharge decreased correspondingly. High spatiotemporal changes in SGI and nitrate loading were found under the combined LULC and groundwater abstraction scenarios. The water yield decreased by 15%. In a large part of the region, the nitrate loading increased by 17-250%. Seasonally controlled groundwater abstraction and water quality monitoring are essential in this region.
识别区域尺度的地表水-地下水相互作用（SGI）对于预测人为活动对地表水和地下水的影响至关重要。然而，大规模的水和养分通量研究依赖于地表水或地下水为重点的模型。本研究旨在模拟城市化的影响，城市化通常伴随着地下水的大量开采和地表水的污染，特别是在发展中国家，对区域尺度的 SGI 和硝酸盐负荷的影响。在研究区域，过去十年城市扩张增加了 3%以上。采用集成的 SWAT-MODFLOW 模型、土壤和水评估工具（SWAT）和模块化有限差分地下水流动（MODFLOW）耦合代码来评估 SGI。通过将 SWAT-MODFLOW 与三维反应传输耦合，可以模拟从点源和非点源向河流输送的养分。流域平均年度结果表明，随着地下水开采量的增加，地下水排泄量减少，而随着土地利用/土地覆盖（LULC）的变化，地下水补给量增加。Belge 季节（二月至五月）地下水补给量显著减少，相应地，河水渗漏和地下水排泄量也减少。在 LULC 和地下水开采综合情景下，发现 SGI 和硝酸盐负荷存在高时空变化。产水量减少了 15%。在该地区的很大一部分地区，硝酸盐负荷增加了 17-250%。该地区需要进行季节性地下水开采和水质监测。
