User's manual for the distributed recharge model ZOODRM

An analysis of recharge, i.e. the quantity of water that infiltrates from the land surface to the aquifer, is an essential step in determining the resources of a groundwater system and simulation of flow in aquifers. Recharge is a complex process, but its quantification is important in order to understand the total water availability from an aquifer. A groundwater model constructed to simulate groundwater flows in a regional aquifer is usually coupled with a distributed recharge model. The need for a distributed recharge model in such a case stems from the fact that the factors affecting the recharge calculations vary temporally and spatially at a regional scale. In addition, distributed recharge models enable the groundwater models to calculate heads and flows at the required point (i.e. nodes for Finite Element and Finite Difference based models) and for the appropriate time steps, (Hughes et al., 2003). Estimates of recharge, therefore, have to be distributed in time and space. A distributed recharge model has been developed for this purpose using object-oriented techniques. This model is called ZOODRM (zoom object-oriented distributed recharge model)