Observed low flow trends in major US river basins

Thursday, 18 December 2014
Maryam Pournasiri Poshtiri and Indrani Pal, University of Colorado Denver, Denver, CO, United States
Changes in global climate would likely be associated with impacts on regional hydrological cycle, such as changes in variability of precipitation and stream flow. Hence, to formulate and implement climate risk management strategies, it is essential to detect where and when hydrological extremes have been changing and to what extent. This scientific research presents where and how low flow characteristics, particularly the occurrence, intensity and severity of hydrological extremes, have been changing in fourteen major river basins within the continental U.S. Of particular interest is to detect if monotonic trends in low flow characteristics shifted with decades, reflecting the known climatic shifts, particularly before and after 1980. Persistent low flow conditions in a river can directly influence water supply for domestic, agricultural, industrial, ecological, and other needs; and a monotonic trend in such persistent low flow condition can lead to chronic water scarcity—a main driver of societal and cross-boundary conflicts around the world. Thus, outcomes from this research are instrumental for the water managers to develop suitable adaptive management measures at the locations and times of need.