Impact of Climate and Land Use Changes on Aquatic Habitats

The short- and long-term effects of climate change have recently become a subject of active research in a variety of earth-science disciplines. The multi-faceted nature of changes in the physical system may also lead to changes in patterns of human activity, such as accelerated rates of water re-allocation and consumption. Such changes could be responsible for many undesirable consequences related to the quality of aquatic habitats in wetlands and estuaries. In particular, runoff and erosion processes in these areas are well known to be highly sensitive to variations in land use practices and precipitation patterns within the watershed. Because the corresponding processes originate at the watershed level, any numerical assessment of a potential impact on these areas must use an integrated approach capable of simulating atmospheric, hydrologic, and channel process components. Models simulating individual processes have already been implemented with moderate-to-satisfactory success. However, models integrating all three system components have not yet been developed. The apparent reason is the complexity of the process coupling, which involves vastly different temporal and spatial scales. Another reason coupled models have not been developed is the processes cut across several disciplines. This study develops a novel tool that approaches the problem by integrating large-scale watershed hydrologic processes with a hydrodynamic model and an evaluation model of biological function. A blueprint methodology for evaluating long-term changes in streamflow, channel morphology, and fish habitat quality is presented for a case study watershed located near Manchester, MI.