An Eco-hydro-geomorphic Perspective to Modeling the Role of Climate in Catchment Evolution

Climate is the energizer of the landscape system. Geomorphic response of a catchment integrates a wide range of climate-driven coupled biotic-abiotic processes along topographic flow paths. As such, modeling the impacts of climate in landscape evolution requires a holistic approach, involving basin ecological and hydrological states, primitive in existing numerical models. To facilitate future model developments, a conceptual diagram of a holistic approach for modeling the role of climate in landscape evolution is presented. We identify hydrology and vegetation dynamics as critical components of future landscape evolution models and discuss how different runoff generation and simple vegetation growth-death processes impact modeled catchment morphology and sediment yields. We illustrate fundamental differences observed in eco-hydro-geomorphic processes across climates using examples from the literature, and emphasize the importance of these differences on catchment evolution. The article concludes with the opinion that simplistic modeling approaches that capture the salient aspects of dominant climate-soil-vegetation-erosion interactions observed in different climates should be adopted in landscape evolution models. This dominant-process approach would also stimulate extensive process-based field research, necessary for the merger of field and modeling perspectives in geomorphology.