Keywords: water logging, groundwater rise, Naga Hammadi, MicroFEM, groundwater drainage, regulator, Nile River, numerical simulation, river barrage, water levels, goundwater modelling, finite element method, FEM, hydraulic performance, cost analysis, subsurface tile drainage, dewatering, pumping wells, Egypt
Numerical simulation of drainage scenarios for lowering groundwater rise due to construction of a new barrage on the Nile River
The government of Egypt constructed a New Naga Hammadi Barrage (NNHB) 3.6 km downstream of the Old Naga Hammadi Barrage (ONHB). Upon construction, the water level raised by about 0.5 and 4 m upstream and within the river reach between ONHB and NNHB respectively. In this paper, a two–layer groundwater model was built using MicroFEM to study the groundwater rising problem. The model was used to examine the hydraulic performance of a number of groundwater drainage scenarios. A cost analysis was carried out and a specific annual cost function was introduced. Moreover, a multi–criteria analysis was conducted to select the most relevant drainage scenario. The analysis shows that the most relevant alternative is to combine two drainage systems; subsurface tile drainage, within the highly affected areas, and dewatering via pumping wells system, elsewhere. It is interesting to note that if the electric power fee is increased from 0.043 to 0.27 USD/kwatt–hr then the most relevant drainage scheme will be the tile drainage.