IMPACTS OF CLIMATE CHANGE ON MISSOURI RWER BASIN WATER YIELD¹

Abstract

Water from the Missouri River Basin is used for multiple purposes. The climatic change of doubling the atmospheric carbon dioxide may produce dramatic water yield changes across the basin. Estimated changes in basin water yield from doubled CO2 climate were simulated using a Regional Climate Model (RegCM) and a physically based rainfall‐runoff model. RegCM output from a five‐year, equilibrium climate simulation at twice present CO2 levels was compared to a similar present‐day climate run to extract monthly changes in meteorologic variables needed by the hydrologic model. These changes, simulated on a 50‐km grid, were matched at a commensurate scale to the 310 subbasin in the rainfall‐runoff model climate change impact analysis. The Soil and Water Assessment Tool (SWAT) rainfall‐runoff model was used in this study. The climate changes were applied to the 1965 to 1989 historic period. Overall water yield at the mouth of the Basin decreased by 10 to 20 percent during spring and summer months, but increased during fall and winter. Yields generally decreased in the southern portions of the basin but increased in the northern reaches. Northern subbasin yields increased up to 80 percent: equivalent to 1.3 cm of runoff on an annual basis.

Experimental drying intensifies burning and carbon losses in a northern peatland

“…Whereas projected annual water yields in North American basins vary by region and by global or regional climate model scenarios, higher evapotranspiration from warming generally is expected to compensate for increases in precipitation in some regions and will magnify the effects of precipitation declines in other regions 18,19 . Boreal ecosystems in particular are estimated to have a high potential vulnerability to climate change in the long term 20 .…”

Future directions for hydropedology: quantifying impacts of global change on land use

“…Hydrologic models provide a framework for examining the complex effects of both climate and land use changes on watershed hydrology (Leavesley, 1994;Amatya et al, 1997;Arnold et al, 1999;Legesse et al, 2000;Arnold and Fohrer, 2005). For example, Stone et al (2001) used the SWAT model (Arnold et al, 1999) coupled with a regional climate model to examine how doubling atmospheric CO 2 affects water yield for the Missouri River Basin. They found that climate change may increase water yield in the fall and winter months but decrease it by 10 to 20% during spring and summer months.…”

Climate uncertainty and implications for U.S. state-level risk assessment through 2050.

“…There are additional studies that consider the cost or physical impacts for particulate state and regions within the U.S. and, in particular, using hydrology as the conveyer of impacts (Vicuna 2009, Christensen 2004, Frei 2002, Chang 2003, Jha 2004, Hayhoe 2004, Dettinger 2004, Frederick 1999, Chen 2001, Gleick 2001, Stone 2001 The IPCC (IPCC 2007b) and Tol( 2007) provide a overview of the many efforts on forecasting the impact of climate change on natural and social systems.…”