Habitat models for assessing river ecosystems and their application to the development of river restoration strategies

In this paper, we describe a model system comprised of hydrodynamic, sediment transport, heat transfer and habitat models. We used this model system to assess the ecosystem situation and investigate the impacts of two ecological restoration strategies in the Mian River, China. Freshwater Reeves shad (Tenualosa reevesii) was selected as the target fish species. Model results indicate a low habitat suitability level for T. reevesii under current hydrological conditions. Due to the habitat protection and restoration requirements in China, further numerical model simulations were conducted to investigate the effects of two ecological restoration strategies: addition of a side-channel and riverbank reconstruction (groin field installation). The long-term effects of the restoration projects were also simulated. The analysis indicated that both restoration strategies would significantly enhance the target fish habitat suitability level, with the OSI (overall suitability index) increasing from 39.9% to 53.7% for the added side-channel strategy and from 39.9% to 61.5% for the river bank reconstruction strategy.