Date of this Version
Great Plains Research Vol. 20 No. 2, 2010
Regional climate models suggest that summers in the Great Plains may become increasingly dry during this century, raising concern about the availability of water resources for irrigation and municipal water supplies. While the models predict drier conditions across the region, the impact of climate change on water availability at the local scale will depend largely upon the soils and their ability to store water during dry periods. This study presents a soil water climatology for Kansas using a climatic water balance approach. Monthly observations of temperature and precipitation for the period 1950–2006 are used to calculate climatologies of actual evapotranspiration, soil water utilization and recharge, and runoff at the soil unit level. Results indicate that actual evapotranspiration rates are small across the state during the winter and spring, reaching a maximum during summer. Soil water utilization is greatest during summer in eastern Kansas; soil water recharge is greatest in the spring in central Kansas and during the fall in eastern Kansas. Soil moisture surplus (runoff) is most pronounced in eastern Kansas during spring and early summer, and soil water shortages (deficit) are common year-round in western Kansas and in soils with low field capacities during the summer months.