Winter Inputs Buffer Streamflow Sensitivity to Snowpack Losses in the Salt River Watershed in the Lo
Marcos D. Robles, John C. Hammond, Stephanie K. Kampf, Joel A. Biederman and Eleonora M. C. Demaria
Arizona, Colorado River Basin
Recent streamflow declines in the Upper Colorado River Basin raise concerns about the sensitivity of water supply for 40 million people to rising temperatures. Yet, other studies in western US river basins present a paradox: streamflow has not consistently declined with warming and snow loss. A potential explanation for this lack of consistency is warming-induced production of winter runoff when potential evaporative losses are low. This mechanism is more likely in basins at lower elevations or latitudes with relatively warm winter temperatures and intermittent snowpacks. We test whether this accounts for streamflow patterns in the Salt River and its tributaries, which is a sub-basin in the Lower Colorado River Basin (LCRB). Despite significant warming from 1968–2011 and snow loss in many of the Salt basins, annual and seasonal streamflow did not decline. Between 25% and 50% of annual streamflow is generated in winter when runoff ratios are generally higher and potential evapotranspiration losses are one-third of potential losses in spring. Short term streamflow responses to winter inputs were larger and more efficient than spring and summer responses and their frequencies and magnitudes increased in 1968–2011 compared to 1929–1967. In total, 75% of the largest winter events were associated with atmospheric rivers, which can produce large cool-season streamflow peaks. We conclude that temperature-induced snow loss in this LCRB sub-basin was moderated by enhanced winter hydrological inputs and streamflow production.
Aerial view of the Parks West restoration site overseen by TNC. Taken March 16, 2020.
Conservancy staffers, Dale Turner and Amanda Rebore, helping to map the Sabn Pedro River in Arizona. They use a GPS unit to denote the end of the water flow on the LowerSan Pedro River. They hiked through the Conservancy’s San Pedro Preserve.
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Mapping the Status of River Streams
Wet/dry mapping provides a low-cost, river-wide snapshot of hydrologic conditions for rivers with interrupted perennial surface flows.
Every June groups of volunteers walk the entire 170 mile length of the San Pedro River and record where it is wet and where it is dry during the hottest, driest time of the year. Twenty years’ worth of data on summertime surface flows in the San Pedro River within the San Pedro Riparian National C[…]
Arizona, Geo Region
Forest Restoration Benefits, Topic
Jamie L Peeler, Lisa McCauley, Kerry L Metlen, Travis Woolley, Kimberley T Davis, Marcos D Robles, Ryan D Haugo, Karin L Riley, Philip E Higuera, Joseph E Fargione
Identifying opportunity hot spots for reducing the risk of wildfire-caused carbon loss in western US conifer forests
As both the climate and wildfire crises intensify and investments are made to dramatically increase the pace of forest restoration across dry forests in the western U.S. through the Wildfire Crisis Strategy, an understanding of where Nature-Based Solutions are the most optimal in lessening climate i[…]
Arizona, Colorado River Basin, Western U.S.
Climate Change, Forest Restoration Benefits
Collaboration, USDA ARS
Ravindra Dwivedi, Joel A. Biederman, Patrick D. Broxton, Kangsan Lee, Willem J.D. van Leeuwen, Jessie K. Pearl
Forest density and snowpack stability regulate root zone water stress and percolation differently at two sites with contrasting ephemeral vs. stable seasonal snowpacks
Much of the western United States depends on high elevation snowpack in forested watersheds for water supply, wildlife habitat, and recreation in both adjacent and downstream communities. The forest-snow-water relationship is well studied in areas with stable – that is, cold – seasonal s[…]