H41A-1271
Assessing the Impacts of Reservoir Regulations and Climate Variability on the Peace River Runoff and Peace-Athabasca-Delta Using a Distributed Hydrological Model
Thursday, 17 December 2015
Poster Hall (Moscone South)
Hammad Javid1,2, Bruce Davison3, Daniel G. Princz1, Prabin Rokaya1, Gonzalo Sapriza1, Howard S. Wheater4, Luis Alejandro Morales-Marin2 and Karl-Erich Lindenschmidt4, (1)University of Saskatchewan, Saskatoon, SK, Canada, (2)Global Institute for Water Security, University of Saskatchewan, School of Environment and Sustainability, Saskatoon, Canada, (3)Environment Canada, Saskatoon, SK, Canada, (4)University of Saskatchewan, Global Institute for Water Security, Saskatoon, SK, Canada
Abstract:
Cold region river catchments functioning is permanently altered locally by the anthropogenic changes and at large scale by the climate changes. Anthropogenic changes are represented particularly by reservoirs that affect the hydrology, and thus the ecology and geomorphology of the river catchments. The Peace River Basin and Peace-Athabasca-Delta (PAD), in western Canada have been experiencing similar kind of anthropogenic changes and shifts in the hydrological regime due to the regulation of Peace River in 1960’s. Since then, ice jam floods have reduced in the region, which are a very important source for replenishment of the PAD perched basins. The previous studies have regarded regulation and climate change to have equal contribution on the drying of PAD. In this study, a physically based and distributed model, MESH (Modélisation Environmentale Communautaire), that couples the Canadian Land Surface Scheme model (CLASS) and hydrological routing model (WATFLOOD), has been used to generate the runoff of Peace River under the natural flow scenario from 1970 to 2010. The reduced ice jam flooding of the PAD is mainly due to the higher freeze up stage in the lower reaches of the Peace River and declining peak flows in the spring. The former is caused by the release of water in the winter for hydropower generation and the latter is due to the filling of reservoir in the spring. Although climate variability has caused decline in summer streamflows for most of the Peace River and the PAD tributaries, as identified by the observed runoff data analysis, it is shown that the spring flows and its occurrence time would still be good enough to cause mechanical breakup of ice and overbank flooding of the PAD, if the Peace River flow was not regulated. Our results are based on the long term observed runoff analysis and the unregulated streamflows simulated by a state of the art physically based model developed by the Environment Canada.
