Assessment of an artificial recharge system through numerical simulations

<p>Artificial recharge is the set of techniques used to increase or facilitate the flow of water to aquifers. It has been a management strategy for centuries to optimize the use of water in regions where the seasonal or inter-annual distribution of surface water produces periods or exceedance and shortage. Water infiltration into aquifers is enhanced such that aquifers serve as short to medium term storage reservoirs. Water is recovered when needed.  Recently, increasing demand of groundwater and the occurrence of more severe and longer droughts in different regions around the world have produced a renewed interest in the application of this management strategy in many countries, particularly in arid and semi-arid regions.</p><p>Infiltration wells are a common method to apply artificial recharge, which allows infiltrating water directly into saturated aquifers or to the unsaturated zone. We performed local-scale numerical simulations of unsaturated flow to model the operation of a single well infiltration system. Based on the results of the simulations, we evaluate its performance considering different conceptualizations of the materials present in the vadose zone. We conclude that the performance of similar systems can be significantly different depending on the distribution of subsurface materials and their properties. Hence, the conceptualization and modeling of such systems require some care about how the inherent heterogeneity of aquifers is included in models.  Last, we provide some recommendations for the design and assessment of similar artificial recharge systems. </p>