Climate change effects on the hydrologic regime within the Churchill-Nelson River Basin

This paper evaluates the possible effects of climate change on four hydrologic variables pertaining to the magnitude and timing of hydrologic events within the Churchill-Nelson River Basin in west-central Canada. By using the Mann-Kendall trend test, and a regionalization procedure, the severity of climatic effects within the river basin may be quantified and used to increase awareness of future consequences for water resource systems planning and management strategies. It was found that the magnitude of hydrologic events decreased over time while snowmelt runoff events occurred earlier. The only exceptions to this behavior were the spring mean monthly streamflow values which exhibited increasing trends due to the potential for snow melting during this period, The timing of a hydrologic event was found to be influenced to the greatest extent by changes in temperature. Geographically, the decreasing trends were concentrated in the southern regions of the river basin while the increasing trends appeared primarily in the northern regions. (C) 1997 Elsevier Science B.V.