Simulation as a decision support for evaluating effects of anthropogenic activities on water resources

Our work addresses this problem in the domain of water management at a catchment scale and consists in evaluating water balances. We have developed a software framework allowing simulation scenarios to be easily run and results about outlet flow and groundwater variation to be easily interpreted. Two kinds of scenarios are considered: (i) climatic scenarios consisting of real data or virtual ones automatically generated in order to simulate wetter or dryer years in comparison with a mean year and (ii) anthropogenic scenarios consisting in modifying the land cover at different scales: parcel, slopes or catchment. The simulation is supported by a methodology allowing catchment models to be built up from a database belonging to a GIS or constituted from an independent application. The methodology is based on a hierarchical and modular approach based on components formalised by sequential machines. Components represent basic phenomena involved in water balance such as evapotranspiration, run off and infiltration. Components are interconnected in order to simulate interactions existing between phenomena at a parcel scale. At an upper modelling level, parcels (resp. slopes) are interconnected in order to represent slopes (resp. the catchment). Infiltration water modelled at a parcel scale is collected in the groundwater body the outflow of which have a part in the river flow.