Simulation and analysis of soil-water conditions in the Great Plains and adjacent areas, central United States, 1951-80

Abstract

Ground-water recharge and consumptive irrigation requirements (CIR) in the Great Plains and adjacent areas largely depend on an environment extrinsic to the ground-water system. This extrinsic environment, which includes climate, soils, and vegetation, determines the water demands of evapotranspiration, the availability of soil water to meet these demands, and the quantity of soil water remaining after these demands are met for potential ground-water recharge.The geographic extent of the Great Plains contributes to large regional differences among all elements composing the extrinsic environment, particularly the climatic factors. Mean annual potential evapotranspiration ranges from about 26 inches in northeastern North Dakota to about 68 inches in eastern New Mexico. Mean annual precipitation ranges from about 10 inches in northcentral Montana to about 48 inches in central Arkansas. Cool-season precipitation, the seasonal precipitation most critical to recharge, is even more regionally variable and ranges from about 2 inches in northeastern Montana to about 23 inches in Arkansas. Variability of soils and vegetation tends to modify local soil-water balances.A soil-water simulation program, SWASP, which synthesizes selected climatic, soil, and vegetation factors, was used to simulate regional Deceased.

Hydrogeology, numerical simulation of groundwater flow, and effects of future water use and drought for reach 1 of the Washita River alluvial aquifer, Roger Mills and Custer Counties, western Oklahoma, 1980–2015

“…Other studies have found that irrigation increases groundwater recharge (Roark and Healy, 1998;McMahon and others, 2011), and recharge rates are greater in irrigated cropland areas compared to natural rangeland or non-irrigated cropland (Scanlon and others, 2005). Annual recharge in irrigated cropland in Nebraska was 0.13-0.30 in/yr greater than annual recharge in non-irrigated cropland and was 1.3-1.6 in/yr greater than in rangeland (Dugan and Zelt, 2000;McMahon and others, 2007;Stanton and others, 2010). To account for possible recharge from crop irrigation and to more closely match published recharge estimates for the Washita River alluvial aquifer, recharge for this aquifer for this study was estimated as 3.15 in/yr, or about 14 percent of precipitation, which is a 25-percent increase from the initial estimates from the SWB code.…”

Main-stem seepage and base-flow recession time constants in the Niobrara National Scenic River Basin, Nebraska, 2016–18

“…in the semiarid steppe of east-central Wyoming to 24 in. in the subhumid glacial-till terrain along the northeastern margin of Nebraska (Fenneman, 1928;Dugan and Zelt, 2000). The Niobrara River alternately flows through wide alluvial valleys, canyons, and valleys bounded by steep escarpments (University of Nebraska-Lincoln, Conservation and Survey Division, 1986;Alexander and others, 2009).…”