Estimate of voluntary and involuntary potential groundwater recharges in urban areas

Abstract

The objective of the study is to quantify the potential groundwater recharge in urban sub-basins in the city of Fortaleza – Ceará. We considered for this natural potential recharge of rain origin and artificial potential recharge that comes from leaks in the supply network and Sanitary Static Sewage System - SSSS, represented respectively by Hydric Potential Natural Recharge – HPNR and Hydric Potencial Artificial Involuntary Recharge - HPAIR. We produces groundwater flow model to identify recharge and discharge areas. The water balance method was applied for the quantification of the HPNR. The estimated HPAIR we accomplished a Geographic Information System – GIS analyze with 2010 Census data to aid the IBGE to observe the sanitation situation of the area. The HPNR’ volume ware superior to HPAIR, that, are constituted by 1,07 million m³/year of domestic effluents via SSSS, and leaks in the water supply network. These has volume estimated at 1.51 million m³/year considering a daily per capita consumption of 225 L/hab. The total potential recharge was estimated at 12.3 million m³/year, and the HPAIP is responsible for 20.9% of the total potential charge.