Modelling surplus canal water releases for artificial recharge of groundwater through surface drainage systems

Intensive agriculture in various countries has resulted in over-exploitatio n of groundwater resources leading to a decline in the water table. Artific ial groundwater recharge offers a good method of preventing the water table from declining further. The Indo-Gangetic plain is currently facing the pr oblem of a declining water table. The network of surface drains constructed to control previous waterlogging could now be used for recharging groundwa ter with surplus canal water during the low irrigation requirement period, as most of the drains cut across the irrigation canals. Therefore, a model was developed to determine the optimum discharge to be released at the head of each drain under natural flow conditions and with interruption in the f low by providing check structures across the drains at suitable intervals. In the proposed method, water is released in such a way that outflow become s zero at the outfall of the drain. The results obtained reveal that the st rategy developed could be adopted for recharging the declining water table through surface drainage systems.