Numerical Simulation of Optimization of Performance of a Radial Collector Well for Riverside Groundwater Intake

Abstract

Riverside groundwater intake has been considered as an effective method to supply sustainably stable quantity and safe quality of the water. The most suitable well type for riverside groundwater intake is a radial collector well because of advantages such as high intake rate and low drawdown. Before construction of a radial collector well in real fields, a quantitative evaluation of its performance and efficiency is necessary to reduce cost and to control amount or quality of intake water. A series of numerical simulations using a detailed numerical modeling technique is performed to optimize performance of radial collector well. First, a model for an aquifer-river linked radial collector well was constructed to consider effects of interaction of a river and an aquifer. Impacts of the radial arm configurations on performance and efficiency of radial collector well were evaluated. And then, impacts of radial collector well specifications and riverbed characteristics on performance of radial collector well ware evaluated. In the results of evaluation of impacts of radial arm configurations, performance and efficiency of radial collector wells are affected by the direction of radial arms, the number of radial arms and the angle between radial arms. On the model for an aquifer-river linked radial collector well, the configuration of optimum performance of radial collector well is when 3 radial arms to river and the angle between adjacent to radial arms is 45°. In the results of evaluation of impacts of radial collector well specifications, the length of radial arms is a more sensitive parameter than the opening ratio of radial arms on performance of radial collector well. In the results of evaluation of impacts of riverbed characteristics, performance of radial collector well is affected by thickness of riverbed and conductivity of riverbed. The performance of radial collector well is the highest when the riverbed does not exist. As the conductance of riverbed increases, the performance of radial collector well is optimized more when the riverbed exists. These detailed numerical simulation results provide a useful guideline for applications to other research fields related for riverside groundwater intake using a radial collector well.