The Relationships between Climatic and Hydrological Changes in the Upper Mississippi River Basin: A SWAT and Multi-GCM Study

Abstract

Changes in major climatic and hydrological quantities in the upper Mississippi River basin and their interrelationships are studied with the Soil and Water Assessment Tool being driven by the contemporary climate and future scenario simulations of 10 global models in the Intergovernmental Panel on Climate Change (IPCC) Data Archive. Although the seasonal cycles of climate and hydrological quantities simulated by the 10 models have differences, the ensemble is very close to the observation. Ensemble predictions show that with warming in all months, precipitation decreases in summer but increases in all other seasons. Correspondingly, streamflow decreases in all seasons except winter, evapotranspiration decreases in JulySeptember and increases in all other months, and snowmelt increases in winter but decreases in spring and fall. To understand the linkages between the cross-century changes of climate and hydrological quantities and the relative importance of the changes of temperature and precipitation to the changes of hydrological quantities, relationships between interannual variations of these quantities are investigated. It is shown that the change rates of the hydrological quantities with respect to temperature and precipitation obtained from regressions of interannual variations can vary greatly from month to month; however, on a monthly basis, they do not change much from the current to the future periods. Evaluations with these change rates indicate that for interannual variations of hydrological quantities, both variations of temperature and precipitation are important, and their relative importance depends on the month of the year. However, the changes of hydrological quantities from the means of the current years to the means of the future are dominated by warming in all months, and the influence from change of precipitation is much smaller. The changes of the hydrological quantities can be well predicted with the change rates from the warming alone.

Impacts of climate change on water resources in the Mediterranean Basin: a case study in Catalonia, Spain

“…The SWAT hydrological model has been broadly applied, obtaining similar model fittings and statistics for North-American, African and Asian case studies (Lu et al 2010, Wang et al 2012, Faramarzi et al 2013, Xu et al 2013, enhancing SWAT as a useful tool to analyse the expected impacts of climate change on water resources. Future improvement of this assessment is needed to reduce uncertainties, including a larger spectrum of climate projections, the consideration of land use and water use scenarios and the effects of increased atmospheric CO 2 concentration on stream flow.…”

“…One of the most widely used models for this purpose is the Soil and Water Assessment Tool (SWAT) hydrological model (e.g. Lu et al 2010, Wang et al 2012, Faramarzi et al 2013, Xu et al 2013. However, this model has rarely been used in studies focused on Mediterranean catchments (Nunes et al 2008).…”

Determining the start, duration, and strength of flood and drought with daily precipitation: Rationale

“…The area studied is the upper Mississippi River basin that covers part of Minnesota, Wisconsin, Iowa, Illinois, and Missouri [Lu et al, 2009]. [Glantz, 1988;Changnon, 1996], and the averaged seasonal cycle of the 25 years are illustrated in Figure 2 with the parameter a being 0.9 and 0.8, respectively.…”

SWAT-Based Streamflow Estimation and Its Responses to Climate Change in the Kadongjia River Watershed, Southern Tibet

“…The Soil and Water Assessment Tool (SWAT), a river watershed-scale model developed by the United States Department of Agriculture (USDA; Arnold et al 1998;Neitsch et al 2001), is an effective tool to model streamflow in a variety of watersheds over long periods of time (e.g., Srinivasan et al 1998;Arnold et al 1999;Bouraoui et al 2005;Zhang et al 2008;J€ urgen et al 2008;Lu et al 2009;Pisinaras et al 2010;Bosch et al 2011). SWAT includes a provision for estimating runoff from frozen soil, which is defined if the temperature in the first soil layer is less than 08C.…”