Title: | Hydrologic alterations predicted by seasonally-consistent subset ensembles of general circulation models |
Authors: | Sheshukov, A.Y. and K.R. Douglas-Mankin |
Year: | 2017 |
Journal: | Climate |
Volume (Issue): | 5(3) |
Pages: | |
Article ID: | 44 |
DOI: | 10.3390/cli5030044 |
URL (non-DOI journals): | |
Model: | SWAT |
Broad Application Category: | hydrologic only |
Primary Application Category: | climate change assessment |
Secondary Application Category: | weather generator effects/processes |
Watershed Description: | 764 km^2 Soldier Creek, which drains portions of Nemaha, Jackson, and Shawnee counties in northeast Kansas, U.S. |
Calibration Summary: | |
Validation Summary: | |
General Comments: | |
Abstract: | Future climate forcing data at the temporal and spatial scales needed to drive hydrologic
models are not readily available. Simple methods to derive these data from historical data or
General Circulation Model (GCM) results may not adequately capture future hydrological variability.
This study assessed streamflow response to daily future climate forcing data produced by a new
method using subsets of multi-model GCM ensembles for the mid-21st century period in northeast
Kansas. Daily timeseries of precipitation and temperature were developed for six future climate
scenarios: stationary, uniform 10% changes in precipitation; shifts based on a 15-GCM ensemble-mean;
and shifts based on three seasonally-consistent subsets of GCMs representing Spring–Summer
combinations that were wetter or drier than the historical period. The analysis of daily streamflow
and hydrologic index statistics were conducted. Stationary 10% precipitation shifts generally bounded
the monthly mean streamflow projections of the other scenarios, and the 15-GCM ensemble-mean
captured non-stationary effects of annual and seasonal hydrological response, but did not identify
important intra-annual shifts in drought and flood characteristics. The seasonally-consistent subset
ensembles produced a range of distinct monthly streamflow trends, particularly for extreme low-flow
and high-flow events. Meaningful water management and planning for the future will require
hydrological impact simulations that reflect the range of possible future climates. Use of GCM
ensemble-mean climate forcing data without consideration of the range of seasonal patterns among
models was demonstrated to remove important seasonal hydrologic patterns that were retained in
the subset ensemble-mean approach. |
Language: | English |
Keywords: | climate change; general circulation models; weather generator; hydrology; SWAT; IHA |