Rainfall-runoff modeling for predictive infiltration and recharge areas for water management in semi-arid basin: a case study from Saadine watershed, Tunisia

Due to the water supply increase and drought-associated problems, optimal water resources management is of a prior need in arid and semi-arid area. The groundwater recharge as an optimal utilization and storage of floodwater constitutes an ideal strategy in water resources management. The purpose of this study is to identify and characterize the spatial distribution of the infiltration and suitable sites for groundwater artificial recharge in a semi-arid basin in Tunisia. The Kineros2 rainfall-runoff model and Geographic Information Systems were used. The datasets required for the model parameters were extracted from maps of soil properties and land cover or extracted from the Digital Elevation Model of the area. The results of simulations reveal that the infiltration values depend on the initial soil moisture. The infiltration rate was closely related to the precipitation quantity and rainstorm duration. The strong rain often leads to overland-flow, overwhelming the infiltration; in contrast, medium and weak but continuous rainfalls favor infiltration process.