Journal Article
Hydrology and Earth System Sciences, vol. 23, iss. 1, pp. 35-49, 2019
Authors
Jiali Qiu, Qichun Yang, Xuesong Zhang, Maoyi Huang, Jennifer C. Adam, Keyvan Malek
Abstract
Abstract. Water management substantially alters natural regimes of
streamflow through modifying retention time and water exchanges among
different components of the terrestrial water cycle. Accurate simulation of
water cycling in intensively managed watersheds, such as the Yakima River basin (YRB) in the Pacific Northwest of the US, faces challenges in
reliably characterizing influences of management practices (e.g., reservoir
operation and cropland irrigation) on the watershed hydrology. Using the Soil
and Water Assessment Tool (SWAT) model, we evaluated streamflow simulations
in the YRB based on different reservoir operation and irrigation schemes.
Simulated streamflow with the reservoir operation scheme optimized by the
RiverWare model better reproduced measured streamflow than the simulation
using the default SWAT reservoir operation scheme. Scenarios with irrigation
practices demonstrated higher water losses through evapotranspiration (ET)
and matched benchmark data better than the scenario that only considered
reservoir operations. Results of this study highlight the importance of
reliably representing reservoir operations and irrigation management for
credible modeling of watershed hydrology. The methods and findings presented
here hold promise to
enhance water resources assessment that can be applied to other intensively managed watersheds.
