Effects of climate change and hydrological signals on streamflow characteristics
Abstract
Human activity has led to accelerated rates of change in climate and land-use. Such changes are expressed in the form of different boundary conditions that cause alterations of watershed hydrological processes, propagating into streamflow. Quantification of the relationship between forcing mechanisms at the watershed level and local changes in stream habitat is a difficult task because of the vastly differing spatial and temporal scales of relevant processes. So far, most models have investigated the effects of climate/hydrologic regime change on streamflow without considering these scaling issues. In order to address the problem, a overlapped, multi-scale, coupled model of watershed hydrology and overland flow has been developed. This also enables obtaining more accurate and specific information on the flow regime, defined by stream depth, velocity, and vorticity. These variables can be subsequently used as key indicators in determining physical habitat conditions for fishes. Among these metrics, average stream reach depth and velocities are frequently used for characterizing habitat suitability because they are easy to obtain and useful for broadly classifying physical habitats. However, recent studies testify that other metrics, such as vorticity, turbulent intensity, area-integrated vorticity (circulation) or turbulent kinetic energy can be used for characterization of fish habitability of a stream. In this study, a comparison of the hydrological regime and its effect on the flow hydrodynamics is carried out for present and future climate conditions. Future regional climate information is downscaled from eight global circulation models using the IPCC 4AR A1B emission scenario. Fifty eight scenarios are generated using a stochastic weather generator combined with the Monte-Carlo simulation. A number of hydrodynamic channel metrics are investigated using the multi-scale coupled model for a case-study watershed located near Manchester, Michigan.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFM.H53B1017K
- Keywords:
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- 1637 GLOBAL CHANGE / Regional climate change;
- 1807 HYDROLOGY / Climate impacts;
- 1813 HYDROLOGY / Eco-hydrology;
- 1850 HYDROLOGY / Overland flow