The comparative analysis of two injection modes and recharge capacity estimation for a radial well in the loess area of China

Abstract

This study is focused on the theoretical substantiation and practical application of the radial well recharge. Two semi-empirical equations were derived for the estimation of the recharge capacity and clogging coefficient of the recharge well, respectively. Two injection modes were applied to analyze the relations between the recharge capacity, water level, and flow rate. Two methods were used to calculate and verify the recharge capacity and clogging coefficient, with a brief analysis of their variation laws. The recharge capacity of the radial well was found to increase with the injection flow, with the following gradual saturation during two injection stages. The recharge capacity increased with the recharge flow, while the clogging coefficient of the second stage was higher than that of the first stage, and exhibited a different variation pattern. The results obtained strongly indicate that the pumping and recharge are hydrological processes, which differ from each other by their physical essence. The available calculation methods based on the pumping theory were found to overestimate the recharge well flow by more than six times. The refined semi-empirical equation provides a more realistic estimation of the recharge capacity of radial wells.