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Enhancement of a parsimonious water balance model to simulate surface hydrology in a glacierized watershed

Journal of Geophysical Research F: Earth Surface

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https://doi.org/10.1029/2017JF004482

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Abstract

The U.S. Geological Survey monthly water balance model (MWBM) was enhanced with the capability to simulate glaciers in order to make it more suitable for simulating cold region hydrology. The new model, MWBMglacier, is demonstrated in the heavily glacierized and ecologically important Copper River watershed in Southcentral Alaska. Simulated water budget components compared well to satellite‐based observations and ground measurements of streamflow, evapotranspiration, snow extent, and total water storage, with differences ranging from 0.2% to 7% of the precipitation flux. Nash Sutcliffe efficiency for simulated and observed streamflow was greater than 0.8 for six of eight stream gages. Snow extent matched satellite‐based observations with Nash Sutcliffe efficiency values of greater than 0.89 in the four Copper River ecoregions represented. During the simulation period 1949 to 2009, glacier ice melt contributed 25% of total runoff, ranging from 12% to 45% in different tributaries, and glacierized area was reduced by 6%. Statistically significant (p < 0.05) decreasing and increasing trends in annual glacier mass balance occurred during the multidecade cool and warm phases of the Pacific Decadal Oscillation, respectively, reinforcing the link between climate perturbations and glacier mass balance change. The simulations of glaciers and total runoff for a large, remote region of Alaska provide useful data to evaluate hydrologic, cryospheric, ecologic, and climatic trends. MWBM glacier is a valuable tool to understand when, and to what extent, streamflow may increase or decrease as glaciers respond to a changing climate.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Enhancement of a parsimonious water balance model to simulate surface hydrology in a glacierized watershed
Series title:
Journal of Geophysical Research F: Earth Surface
DOI:
10.1029/2017JF004482
Volume:
123
Issue:
5
Year Published:
2018
Language:
English
Publisher:
AGU
Contributing office(s):
National Research Program - Central Branch
Description:
17 p.
First page:
1116
Last page:
1132