Validation of the STRIVE model for coupling ecological processes and surface water flow

The 1D model package STRIVE is verified for simulating the interaction between ecological processes and surface water flow. The model is general and can be adapted and further developed according to the research question. The hydraulic module, based on the Saint-Venant equations, is the core part. The presence of macrophytes influences the water quality and the discharge due to the flow resistance of the river, expressed by Manning's coefficient, and allows an ecological description of the river processes. Based on the advection–dispersion equation, water quality parameters are incorporated and modelled. Calculation of the water quantity parameters, coupled with water quality and inherent validation and sensitivity analysis, is the main goal of this research. An important study area is the River Aa near Poederlee (Belgium), a lowland river with a wealth of vegetation growth, where discharge and vegetation measurements are carried out on a regular basis. The developed STRIVE model shows good and accurate calculation results. The work highlights the possibility of STRIVE to model flow processes, water quality aspects and ecological interaction combined and separately. Coupling of discharges, water levels, amount of biomass and tracer values provides a powerful prediction modelling tool for the ecological behaviour of lowland rivers.