As per the new approach to mange the total water cycle by onsite storage and infiltration systems we needed to develop a physically based process model for catchment simulation that can incorporate the effects of infiltration system. I was working at the Nippon Koei AI research division at that time and developed a new model we called 'Similar Hydrologic Element Response' or SHER model.
Using a detailed GIS we divide catchment to a large number of grids. Then group areas by slope, soil type, depth to ground water and model each group using a combined model where the storage and transport in subsurface is estimated from soil moisture-suction-conductivity relations.
