Extraction and re-implementation of SWAT-Model calculations under the MAELIA platform in order to simulate the socio-environmental impacts of norms

YI HONG , Jose Miguel Sanchez Perez, Sabine Sauvage, Olivier Therond

MAELIA (Multi-Agent for EnvironmentaL norms Impact Assesment) is an agent-based simulation platform designed to assess the impact of alternative water management policies at the watershed level. It simulates interactions between human activities (agricultural, domestic and industrial withdrawals, regulations of water uses) and ecological processes (crop growth, plant evapotranspiration and water flow). To simulate the water cycles at the sub-watershed level, the representations of hydrological processes in SWAT are analysed and re-implemented in MAELIA.
In this paper, we discussed some of the design choices, simplifications (e.g. overland flow, soil temperature, perched water table and bypass flow are not simulated) and modifications (e.g. different methods of generating HRUs, elevation bands, snow water are calculated in the sub-basin loops etc.) we made in order to integrate SWAT hydrological formalisms: surface-runoff, soil water, snow water, groundwater, evapotranspiration and water-routing. Otherwise, MAELIA use some specific processes for simulating crops growth (Jeud’O model), weather generator (SAFRAN model) and water management (Multi-agents). The MAELIA platform was tested on a 6000 km2 watershed at the upstream part of Adour-Garonne-Basin in south-west of France for a 10-years period (2000-2009). The results show that the MAELIA platform reasonably reproduces stream flow hydrograph for a long-term simulation, the effects of water management restrictions are well represented, especially during the low-water periods. Sensibility analysis shows that some parameters in MAELIA are less influential comparing with SWAT model (base-flow and soil properties parameters). The MAELIA platform is a promising agent-based, real-time model for simulating the impacts of water management policies including human behaviour and economical aspects.