Evaluation of the impact of variable recharge in an urban aquifer associated with land use and occupation.

In northeastern Brazil, the recharge of unconfined urban aquifers is substantially affected by high rates of soil sealing, as well as infiltration of sanitary effluents and water infiltration by water loss in the distribution network. This research aimed to evaluate the effects of variable recharge resulting from land use and occupation, considering the artificial recharge contributions within an unconfined urban aquifer. The methodology was based on developing numerical models with scenario analysis, individualizing areas with higher and lower population densities. The results demonstrate significant variations in the 15-m water table in several areas and inversions of the underground flow. The saturation reserves varied by about 10% between the current and critical scenarios. The results reported here may contribute to the management of shallow aquifers in similar scenarios, especially in terms of urbanization rates and efficiency in the water distribution and the sanitary effluent collection network. • The impacts of varying recharge rates compromise water availability in an unconfined urban aquifer. • Contributions from artificial recharge significantly change the water table levels of urban aquifers in northeastern Brazil. • Numerical models for estimating recharge in unconfined aquifers in urban areas. • Simulation results show changes in underground flow through changes in recharges. [ABSTRACT FROM AUTHOR]