Study of Climate Change to Hydrologic Processes in a Snow-dominant Area

Abstract:

The focus of this study is to identify a representative climate change models in Coupled Model Intercomparison Project phase 5 (CMIP5) for regional hydrologic study in Lehman Creek watershed, a typical snow-dominated area located in Great Basin National Park, eastern Nevada for a period of 55 years i.e. 1950 to 2005. Features of three variables: precipitation, maximum temperature and minimum temperature were analyzed and compared with the available 21 CMIP5 model ensembles. Results identified a subset of 6 climate models among the CMIP5 ensembles that showed statistical consistency in features of trend and variability with the chosen variables. For a validation, a physically- based distributed hydrologic model was developed using Precipitation-Runoff Modeling System (PRMS) in Lehman Creek watershed. Runoff simulations were obtained by driving PRMS model with the products of these identified climate models, and were well validated with observed data. However, the magnitudes of CMIP5 precipitation were too low and could not adequately represent to the observed annual precipitation. Adjustment of precipitation will be needed and extra caution should be paid if these 6 model products are used in regional hydrologic processes simulation in future as well as water resources planning.