skip to main content

DOE PAGESDOE PAGES

Title: Climate-driven disturbances in the San Juan River sub-basin of the Colorado River

Accelerated climate change and associated forest disturbances in the southwestern USA are anticipated to have substantial impacts on regional water resources. Few studies have quantified the impact of both climate change and land cover disturbances on water balances on the basin scale, and none on the regional scale. In this work, we evaluate the impacts of forest disturbances and climate change on a headwater basin to the Colorado River, the San Juan River watershed, using a robustly calibrated (Nash–Sutcliffe efficiency 0.76) hydrologic model run with updated formulations that improve estimates of evapotranspiration for semi-arid regions. Our results show that future disturbances will have a substantial impact on streamflow with implications for water resource management. Our findings are in contradiction with conventional thinking that forest disturbances reduce evapotranspiration and increase streamflow. In this study, annual average regional streamflow under the coupled climate–disturbance scenarios is at least 6–11 % lower than those scenarios accounting for climate change alone; for forested zones of the San Juan River basin, streamflow is 15–21 % lower. The monthly signals of altered streamflow point to an emergent streamflow pattern related to changes in forests of the disturbed systems. Exacerbated reductions of mean and low flows under disturbancemore » scenarios indicate a high risk of low water availability for forested headwater systems of the Colorado River basin. Furthermore, these findings also indicate that explicit representation of land cover disturbances is required in modeling efforts that consider the impact of climate change on water resources.« less
Authors:
ORCiD logo [1] ;  [2] ;  [1] ;  [3] ;  [1] ; ORCiD logo [2] ;  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Arizona State Univ., Tempe, AZ (United States)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Publication Date:
Report Number(s):
PNNL-SA-129830; LA-UR-17-27609
Journal ID: ISSN 1607-7938
Grant/Contract Number:
AC05-76RL01830; AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Hydrology and Earth System Sciences (Online)
Additional Journal Information:
Journal Name: Hydrology and Earth System Sciences (Online); Journal Volume: 22; Journal Issue: 1; Journal ID: ISSN 1607-7938
Publisher:
European Geosciences Union (EGU)
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Laboratory Directed Research and Development (LDRD) Program
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; Earth Sciences
OSTI Identifier:
1421318
Alternate Identifier(s):
OSTI ID: 1430004