The Western Mountain Aquifer (Yarkon-Taninim) of Israel is one of the country's major water resources and partially flows through a karst system. During late winter 2013, maintenance actions were performed on a central sewage pipe that caused sewage to leak into the creek located in the study area. Carbamazepine (CBZ) was used as an indicator for the presence of sewage in the groundwater. The research goal was to develop a mathematical model for quantifying flow and contaminant transport processes in the karst/fractured-porous unsaturated zone and groundwater system. The model was used to simulate CBZ transport during and after an observed sewage leakage event. A quasi-3D dual permeability numerical model represents the 'vadose zone – aquifer' system, by a series of 1D vertical flow and transport equations solved in a variably-saturated zone and by 3D-saturated flow and transport equation in groundwater. The results of simulation showed that after the leakage stopped, significant amounts of CBZ were retained in the porous matrix of the unsaturated zone below the creek. Water redistribution and slow recharge during the dry summer season contributed to a continuous supply of CBZ to the groundwater in the vicinity of the creek and hundreds of meters downstream.

中文翻译：

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以卡马西平为指标模拟碳酸盐含水层中的污水泄漏和运输

以色列的西部山区蓄水层（Yarkon-Taninim）是该国的主要水资源之一，部分流经岩溶系统。在2013年冬末，对中央排污管道进行了维护，这使排污物泄漏到研究区域的小河中。卡马西平（CBZ）用作指示地下水中存在污水的指标。研究目标是建立一个数学模型，以量化岩溶/裂缝-多孔非饱和带和地下水系统中的水流和污染物输送过程。该模型用于模拟观察到的污水泄漏事件期间和之后的CBZ传输。准3D双渗透率数值模型代表“渗流带-含水层”系统，通过一系列在饱和区中求解的一维垂直流和输运方程，以及在地下水中通过3D饱和流和输运方程求解。模拟结果表明，在泄漏停止后，大量的CBZ保留在小溪以下非饱和区的多孔基质中。在干旱的夏季，水的重新分配和缓慢的补给促使向小河附近和下游数百米的地下水连续供应CBZ。