Submitted to: USGS - Scientific Investigations Report
Publication Type: Government Publication
Publication Acceptance Date: July 15, 2011
Publication Date: September 20, 2011
Citation: Garbrecht, J.D., Moriasi, D.N. 2011. Climate of the Fort Cobb reservoir watershed, southwestern Oklahoma, 1940-2007. In: Becher, C.J. (ed.). Assessment of Conservation Practices in the Fort Cobb Reservoir Watershed, Southwestern Oklahoma. USGS - Scientific Investigations Report. Available: http://pubs.usgs.gov/sir/2010/5257/. Interpretive Summary: Abstract Only.
Technical Abstract: Climate considerations are essential for assessing the hydrologic system behavior of a watershed and interpreting the effectiveness of soil and water conservation efforts. Here relevant climatic characteristics of the Fort Cobb Reservoir watershed are identified. A review of the 1940-2005 annual precipitation record revealed several persistent multi-year pluvial and drought time periods. The largest pluvial time period was in the 1980s and 1990s. Mean monthly precipitation was bimodal with the first peak in May and a smaller second peak in September. Since 1980, the month of March has seen a substantial increase in precipitation, whereas precipitation amount during summer months remained essentially unchanged. Spatial variability of monthly and daily precipitation was large. More intense precipitation events were recorded during summer months than during winter months. The USDA-ARS network of climate stations in the Fort Cobb Reservoir watershed provides adequate coverage to capture the spatial variability of precipitation for watershed-scale hydrologic and environmental investigations. Annual air temperature did not reveal a relevant trend or pronounced multi-year variations, nor was there any evidence of a notable correlation between annual temperature and precipitation variations. Spatial variability of monthly air temperature was within the instrument error range and of little practical significance for most hydrologic applications.