Does Dynamical Downscaling Matter for Climate Change Adaptation on the Colorado River? (Invited)
Abstract
Much is made of the need for high resolution information about future climate change for use in climate impacts and adaptation studies. This has particularly been true for efforts in the area of water research. Various studies have demonstrated that there can be important differences in calculations of the hydrologic impacts of climate change based on the use of high resolution information compared to information from coarse resolution global models. There has been less work comparing what difference it makes based on how the information is downscaled and even less on what difference this would make in the context of actual adaptation planning for water resources. The Bureau of Reclamation's Colorado River Basin Water Supply and Demand Study ("Basin Study") is investigating the impacts of climate altered hydrologies on future water supply and demand imbalances in the basin, and will develop and analyze adaptation strategies. The Basin Study is using climate information that has been downscaled using the Bias-Corrected Spatial Disaggregation (BCSD) method. Working with Reclamation researchers, and in parallel to the Basin Study, we investigate the hypothesis that dynamically downscaled projections would make a difference to this impacts and adaptation study. Specifically we compare results from two different approaches to downscaling climate projections for this region for the mid 21st century based on the A2 emissions scenarios: BCSD, and dynamically downscaled projections from the NARCCAP program. The climate projections run through the Variable Infiltration Capacity (VIC) hydrology model and the Colorado River Simulation System (CRSS) operations and planning model. Development of decision-relevant metrics of system performance is part of the Basin Study, and will likely play a role in the evaluation of adaptation strategies. Here we present here a comparison of these decision-relevant metrics under the two downscaling methods and an analysis of the influence on these metrics of using dynamically downscaled climate projections.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMGC52B..05B
- Keywords:
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- 1637 GLOBAL CHANGE / Regional climate change;
- 1655 GLOBAL CHANGE / Water cycles;
- 1807 HYDROLOGY / Climate impacts