Modeling groundwater recharge through rainfall in the Far-North region of Cameroon

The Far-North region of Cameroon is threatened by extreme water shortage. Over the years groundwater has increasingly been used as the main source of domestic water supply. In spite of the increased, groundwater exploitation has been done without adequate planning. One of the key parameters of a sustainable groundwater management is the regional groundwater recharge rate, which defines the upper limit for which groundwater abstraction should not exceed. This paper summarizes the results of transferring the water balance model GROWA to the Far-North region of Cameroon. The main aim was to assess the spatial distributed groundwater recharge rate through rainfall. Due to the lack of adequate regional data bases, international data sources, e.g. the World soil map in scale of 1: 3,000,000 were used to derive the input parameters needed to run GROWA model. The simulated GROWA results show a satisfying agreement with existing groundwater recharge rate assessments for most areas of the study region. Against this background, it was concluded that GROWA model results represent reliable reference values for groundwater recharge through rainfall even though the input parameters were derived from small-scale generalized international maps. This approach provides a relevant initial step for a more detailed groundwater recharge estimate. A more accurate estimation for groundwater recharge should be carried out once the input data for the study area are available in higher spatial resolution including runoff records for a plausibility check of the modeled water quantities for groundwater recharge.