ABSTRACT
This study was carried out to estimate direct recharge in the Sokoto-Rima river basin, Nigeria, using a soil moisture deficit model. Thereafter, the sensitivity of the model to input and model parameters was investigated. The mean annual recharge for the study period was found to be 255.0mm. The incidence of recharge was validated by comparison of the recharge estimates with well hydrographs obtained in the region. Further studies would be required before the amount of recharge can be fully validated. The results of the sensitivity analysis show that variations in rainfall and potential evapotranspiration values significantly affect the direct recharge values. From the experience gained in this study, one would call for a more efficient system for data collection, storage and retrieval.