WetSpass: A flexible, GIS based, distributed recharge methodology for regional groundwater modelling

Regional groundwater models used for analysing groundwater systems (infiltration-discharge relations) are often quasi-steady state and therefore need long-term average recharge input. On the other hand, the spatial variation in the recharge due to distributed land-use, soil type, slope, groundwater level, meteorological conditions, etc. can be significant and should be accounted for. Hence, WetSpass was built as a physically based methodology for estimation of the long-term average spatial patterns of surface runoff, actual evapotranspiration and groundwater recharge. The model is especially suitable for studying long-term effects of land-use changes on the water regime in a basin. The computer model was integrated in the GIS Arc View. Its set-up is extremely flexible; it allows easy new definition of natural or man-made land-use types. This paper describes the concept of the model and gives an example of a calibrated WetSpass recharge map.SCOPUS: ar.j