Management of water resources of agricultural catchments has emerged as an environmental priority due to the effects of anthropogenic discontinuities or activities such as the field limits, embankments, drains, ditches, and agricultural practices on runoff, erosion and pollutant transport. MHYDAS, a physically based distributed hydrological model, was especially developed to model water, pollutant and erosion transport, taking into account these discontinuities and practices. A modular approach was undertaken using the platform OpenFLUID, which enables the user to build his own version of MHYDAS by combining various processes (interception, runoff, channel routing, infiltration, transfer in the soil, pollutant fate and transfer, erosion transfer) as a function of the objective of the study and the availability and the accuracy of the data. Application cases are shown and compared in various agro-hydro-climatic conditions in order to study the impact on water and pollutant transfer of tillage practices in the vineyard, stem-flow in tropical volcanic zone and drains in drained catchments. Finally, the model was applied to simulate the impact of various land-use scenarios.