Article
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

The High Plains Aquifer (HPA) underlies parts of eight states and 208 counties in the central area of the United States (U.S.). This region produces more than 9% of U.S. crops sales and relies on the aquifer for irrigation. However, these withdrawals have diminished the stock of water in the aquifer. In this paper, we investigate the aggregate county‐level effect on the HPA of groundwater withdrawal for irrigation, of climate variables, and of energy price changes. We merge economic theory and hydrological characteristics to jointly estimate equations describing irrigation behavior and a generalized water balance equation for the HPA. Our simple water balance model predicts, at average values for irrigation and precipitation, an HPA‐wide average decrease in the groundwater table of 0.47 feet per year, compared to 0.48 feet per year observed on average across the HPA during this 1985–2005 period. The observed distribution and predicted change across counties is in the (−3.22, 1.59) and (−2.24, 0.60) feet per year range, respectively. The estimated impact of irrigation is to decrease the water table by an average of 1.24 feet per year, whereas rainfall recharges the level by an average of 0.76 feet per year. Relative to the past several decades, if groundwater use is unconstrained, groundwater depletion would increase 50% in a scenario where precipitation falls by 25% and the number of degree days above 36°C doubles. Editor’s note: This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series. Research Impact Statement: Results show the average net effect of irrigation in the High Plains Aquifer is a reduction in groundwater level of 0.47 feet per year. Climate change could significantly increase the rate of change.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Groundwater declines due to pumping remain unlikely, but future prospects for irrigation in the Northern High Plains may be threatened due to increased irrigation demand, changing regulatory and interstate water management agreements (Schlager and Heikkila, 2009), changing climate (Lauffenburger et al., 2018;Silva et al., 2019;Evett et al., 2020) and repeats of severe drought (Basara et al., 2013;Whittemore et al., 2016;Freire-González et al., 2017; NeDNR and TPNRD, 2019). ...
Article
Areas across the High Plains (Ogallala) Aquifer region are experiencing unsustainable groundwater level declines and impacts to streamflow due to increasing human influence, posing challenges for sustaining future agricultural economies and groundwater resources. State and local agencies manage water using groundwater models, which are not at the same temporal and spatial scale as water management on farms. Well-informed agricultural water usage cannot be achieved without reliable and cost-effective water use at farm scale. Water meters are expensive and rarely installed unless required by the state or other regulatory agency; however, most center pivots have their own power supply, which reports real-time electricity consumption. Thus, finding novel ways of measuring real-time water usage from center pivot irrigation provides essential information to farmers and watershed managers balancing economic, sustainability, and governance decisions. This study leverages data gathered across the food-energy-water nexus by translating electrical measurements gathered in 15-minute time intervals on 10 center pivot agricultural production wells in western Nebraska into estimates of water delivery. Water delivery estimated using an electrical run-time algorithm and ultrasonic flow tests is found to be within 6.60% when compared to water delivery measured taken independently with calibrated flow meters. Translating electrical measurements from wells is an accurate way to estimate water withdrawals relative to the costs, but faces uncertainty arising from ultrasonic flow tests, field topography, and variable water delivery. Hydrologic modeling runs using the COHYST regulatory model for the Platte Basin demonstrated that errors in pumping on the scale of field-level estimated uncertainties can have a meaningful effect on estimated streamflow in the Platte River during peak pumping months, but that the model is constructed in a way that prevents assessment of the effects of the spatial distribution of pumping error. This novel data approach takes advantage of reliable and cost-effective data gathering across the rural electric smart grid to provide cost-effective food-energy-water solutions—supporting well-informed and economic use of water resources and models. Advisor: Erin Haacker
Article
Groundwater over-extraction is a problem facing many countries around the world. Water pricing and developing property rights to enable groundwater trade are potential demand-based approaches to address the over-extraction of groundwater resources. However, successful implementation of groundwater trading requires knowledge about groundwater demand and its interaction/substitutability with surface-water; and, given the paucity of empirical data on groundwater markets, price elasticity of groundwater demand is rarely estimated in the literature. We analysed 10 years of monthly surface and groundwater temporary market data (July 2008–April 2018) within the Murrumbidgee catchment of the Murray-Darling Basin, Australia, to explore a) the lead-lag relationship between surface and groundwater temporary markets; and b) the price elasticity of groundwater market demand. Results illustrate that surface-water markets show price leadership to groundwater temporary markets, and that groundwater demand is price elastic, with a –1.05 price elasticity estimate in our time-period.
Technical Report
Full-text available
This document is one of series of regional climate descriptions designed to provide input that can be used in the development of the National Climate Assessment (NCA). As part of a sustained assessment approach, it is intended that these documents will be updated as new and well-vetted model results are available and as new climate scenario needs become clear. It is also hoped that these documents (and associated data and resources) are of direct benefit to decision makers and communities seeking to use this information in developing adaptation plans. There are nine reports in this series, one each for eight regions defined by the NCA, and one for the contiguous U.S. The eight NCA regions are the Northeast, Southeast, Midwest, Great Plains, Northwest, Southwest, Alaska, and Hawai‘i/Pacific Islands. These documents include a description of the observed historical climate conditions for each region and a set of climate scenarios as plausible futures – these components are described in more detail below. While the datasets and simulations in these regional climate documents are not, by themselves, new, (they have been previously published in various sources), these documents represent a more complete and targeted synthesis of historical and plausible future climate conditions around the specific regions of the NCA. There are two components of these descriptions. One component is a description of the historical climate conditions in the region. The other component is a description of the climate conditions associated with two future pathways of greenhouse gas emissions.
Article
Full-text available
Percolation of precipitation through unsaturated zones is important for recharge of ground water. Rain and snowmelt at land surface are partitioned into different pathways including runoff, infiltration, evapotranspiration, unsaturated-zone storage, and recharge. A new package for MODFLOW-2005 called the Unsaturated-Zone Flow (UZF1) Package was developed to simulate water flow and storage in the unsaturated zone and to partition flow into evapotranspiration and recharge. The package also accounts for land surface runoff to streams and lakes. A kinematic wave approximation to Richards’ equation is solved by the method of characteristics to simulate vertical unsaturated flow. The approach assumes that unsaturated flow occurs in response to gravity potential gradients only and ignores negative potential gradients; the approach further assumes uniform hydraulic properties in the unsaturated zone for each vertical column of model cells. The Brooks-Corey function is used to define the relation between unsaturated hydraulic conductivity and water content. Variables used by the UZF1 Package include initial and saturated water contents, saturated vertical hydraulic conductivity, and an exponent in the Brooks-Corey function. Residual water content is calculated internally by the UZF1 Package on the basis of the difference between saturated water content and specific yield. The UZF1 Package is a substitution for the Recharge and Evapotranspiration Packages of MODFLOW-2005. The UZF1 Package differs from the Recharge Package in that an infiltration rate is applied at land surface instead of a specified recharge rate directly to ground water. The applied infiltration rate is further limited by the saturated vertical hydraulic conductivity. The UZF1 Package differs from the Evapotranspiration Package in that evapotranspiration losses are first removed from the unsaturated zone above the evapotranspiration extinction depth, and if the demand is not met, water can be removed directly from ground water whenever the depth to ground water is less than the extinction depth. The UZF1 Package also differs from the Evapotranspiration Package in that water is discharged directly to land surface whenever the altitude of the water table exceeds land surface. Water that is discharged to land surface, as well as applied infiltration in excess of the saturated vertical hydraulic conductivity, may be routed directly as inflow to specified streams or lakes if these packages are active; otherwise, this water is removed from the model. The UZF1 Package was tested against the U.S. Geological Survey’s Variably-Saturated Two-Dimensional Flow and Transport Model for a vertical unsaturated flow problem that includes evapotranspiration losses. This report also includes an example in which MODFLOW-2005 with the UZF1 Package was used to simulate a realistic surface-water/ground-water flow problem that includes time and space variable infiltration, evapotranspiration, runoff, and ground-water discharge to land surface and to streams. Another simpler problem is presented so that the user may use the input files as templates for new problems and to verify proper code installation.
Article
Full-text available
Aquifers supporting irrigated agriculture are under stress worldwide as a result of large pumping-induced water deficits. To aid in the formulation of more sustainable management plans for such systems, we have developed a water balance approach for assessing the impact of proposed management actions and the prospects for aquifer sustainability. Application to the High Plains aquifer (HPA) in the state of Kansas in the United States reveals that practically achievable reductions in annual pumping (<22%) would have stabilized areally averaged water levels over much of the Kansas HPA from 1996 to 2013. This demonstrates that modest pumping reductions can have a significant impact and highlights the importance of reliable pumping data for determining the net inflow (capture) component of the water balance. The HPA is similar to many aquifers supporting critically needed agricultural production, so the presented approach should prove of value far beyond the area of this initial application.
Article
Full-text available
Irrigation water demand is estimated using field-level panel data from Kansas over 16 years. The cost of pumping varies over time due to changes in energy prices and across space due to differences in the depth to water. Exploiting this variation allows us to estimate the demand elasticity while controlling for field-farmer and year fixed effects. Fixed effects also allow us to control for land use without an instrument or assumptions about the distribution of errors. Our estimates of water demand are used to calculate the cost of reducing irrigation water use through water pricing, irrigation cessation, and intensity-reduction programs.
Article
Full-text available
A large imbalance between recharge and water withdrawal has caused vital regions of the High Plains Aquifer (HPA) to experience significant declines in storage. A new predevelopment map coupled with a synthesis of annual water levels demonstrates that aquifer storage has declined by approximately 410 km(3) since the 1930s, a 15% larger decline than previous estimates. If current rates of decline continue, much of the Southern High Plains and parts of the Central High Plains will have insufficient water for irrigation within the next 20 to 30 years, whereas most of the Northern High Plains will experience little change in storage. In the western parts of the Central and northern part of the Southern High Plains, saturated thickness has locally declined by more than 50%, and is currently declining at rates of 10% to 20% of initial thickness per decade. The most agriculturally productive portions of the High Plains will not support irrigated production within a matter of decades without significant changes in management. © 2015, National Ground Water Association.
Technical Report
Full-text available
Water use in the United States in 2010 was estimated to be about 355 billion gallons per day (Bgal/d), which was 13 percent less than in 2005. The 2010 estimates put total withdrawals at the lowest level since before 1970. Freshwater withdrawals were 306 Bgal/d, or 86 percent of total withdrawals, and saline-water withdrawals were 48.3 Bgal/d, or 14 percent of total withdrawals. Fresh surface-water withdrawals (230 Bgal/d) were almost 15 percent less than in 2005, and fresh groundwater withdrawals (76.0 Bgal/d) were about 4 percent less than in 2005. Saline surface-water withdrawals were 45.0 Bgal/d, or 24 percent less than in 2005. Updates to the 2005 saline groundwater withdrawals, mostly for thermoelectric power, reduced total saline groundwater withdrawals to 1.51 Bgal/d, down from the originally reported 3.02 Bgal/d. Total saline groundwater withdrawals in 2010 were 3.29 Bgal/d, mostly for mining use. Thermoelectric power and irrigation remained the two largest uses of water in 2010, and total withdrawals for both were notably less than in 2005. Withdrawals in 2010 for thermoelectric power were 20 percent less and withdrawals for irrigation were 9 percent less than in 2005. Similarly, other uses showed reductions compared to 2005, specifically public supply (–5 percent), self-supplied domestic (–3 percent), self-supplied industrial (–12 percent), and livestock (–7 percent). Only mining (39 percent) and aquaculture (7 percent) reported larger withdrawals in 2010 compared to 2005. Thermoelectric power, irrigation, and public-supply withdrawals accounted for 90 percent of total withdrawals in 2010. Withdrawals for thermoelectric power were 161 Bgal/d in 2010 and represented the lowest levels since before 1970. Surface-water withdrawals accounted for more than 99 percent of total thermoelectric-power withdrawals, and 73 percent of those surface-water withdrawals were from freshwater sources. Saline surface-water withdrawals for thermoelectric power accounted for 97 percent of total saline surface-water withdrawals for all uses. Thermoelectric-power withdrawals accounted for 45 percent of total withdrawals for all uses, and freshwater withdrawals for thermoelectric power accounted for 38 percent of the total freshwater withdrawals for all uses. Irrigation withdrawals were 115 Bgal/d in 2010 and represented the lowest levels since before 1965. Irrigation withdrawals, all freshwater, accounted for 38 percent of total freshwater withdrawals for all uses, or 61 percent of total freshwater withdrawals for all uses excluding thermoelectric power. Surface-water withdrawals (65.9 Bgal/d) accounted for 57 percent of the total irrigation withdrawals, or about 12 percent less than in 2005. Groundwater withdrawals were 49.5 Bgal/d in 2010, about 6 percent less than in 2005. About 62,400 thousand acres were irrigated in 2010, an increase from 2005 of about 950 thousand acres (1.5 percent). The number of acres irrigated using sprinkler and microirrigation systems continued to increase and accounted for 58 percent of the total irrigated lands in 2010. Public-supply withdrawals in 2010 were 42.0 Bgal/d, or 5 percent less than in 2005, and represented the first declines in public-supply withdrawals since the 5-year reporting began in 1950. Total population in the United States increased from 300.7 million people in 2005 to 313.0 million people in 2010, an increase of 4 percent. Public-supply withdrawals accounted for 14 percent of the total freshwater withdrawals for all uses and 22 percent of freshwater withdrawals for all uses excluding thermoelectric power. The number of people that received potable water from public-supply facilities in 2010 was 268 million, or about 86 percent of the total U.S. population. This percentage was unchanged from 2005. Self-supplied domestic withdrawals were 3.60 Bgal/d, or 3 percent less than in 2005. More than 98 percent of the self-supplied domestic withdrawals were from groundwater sources. Self-supplied industrial withdrawals were 15.9 Bgal/d in 2010, a 12 percent decline from 2005, and continued the downward trend since the peak of 47 Bgal/d in 1970. Total self-supplied industrial withdrawals were 4 percent of total withdrawals for all uses and 8 percent of total withdrawals for all uses excluding thermoelectric power. Most of the total self-supplied industrial withdrawals were from surface-water sources (82 percent), and nearly all (93 percent) of those surface-water withdrawals were from freshwater sources. Nearly all of the groundwater withdrawals for self-supplied industrial use (98 percent) were from freshwater sources. Total aquaculture withdrawals were 9.42 Bgal/d in 2010, or 7 percent more than in 2005, and surface water was the primary source (81 percent). Most of the surface-water withdrawals occurred at facilities that operated flowthrough raceways, which returned the water to the source directly after use. Aquaculture withdrawals accounted for 3 percent of the total withdrawals for all uses and 5 percent of the total withdrawals for all uses excluding thermoelectric. Total mining withdrawals in 2010 were 5.32 Bgal/d, or about 1 percent of total withdrawals from all uses and 3 percent of total withdrawals from all uses excluding thermoelectric. Mining withdrawals accounted for the largest percentage increase (39 percent) in water use between 2005 and 2010 among all the categories. Groundwater withdrawals accounted for 73 percent of the total mining withdrawals, and the majority of the groundwater was saline (71 percent). The majority (80 percent) of surface-water withdrawals for mining was freshwater. Livestock withdrawals in 2010 were 2.00 Bgal/d, or 7 percent less than in 2005. All livestock withdrawals were from freshwater sources, mostly from groundwater (60 percent). Livestock withdrawals accounted for about 1 percent of total freshwater withdrawals for all uses excluding thermoelectric power. In 2010, more than 50 percent of the total withdrawals in the United States were accounted for by 12 States. California accounted for about 11 percent of the total withdrawals and 10 percent of freshwater withdrawals in the United States, predominantly for irrigation. Texas accounted for about 7 percent of total withdrawals, predominantly for thermoelectric power, irrigation, and public supply. Florida accounted for 18 percent of the total saline-water withdrawals in the United States, mostly from surface-water sources for thermoelectric power. Oklahoma and Texas accounted for about 70 percent of the total saline groundwater withdrawals in the United States, mostly for mining.
Article
Full-text available
Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.
Article
Full-text available
On the Texas High Plains, water from the Ogallala aquifer is used to supplement irrigation requirements, since annual rainfall is below 20.5 in/ year. This study addresses land and water demand by testing the effects of water costs, crop prices, and technology on water use and crop production acreages.
Article
Full-text available
1] Using panel data from a period of water rate reform, this paper estimates the price elasticity of irrigation water demand. Price elasticity is decomposed into the direct effect of water management and the indirect effect of water price on choice of output and irrigation technology. The model is estimated using an instrumental variables strategy to account for the endogeneity of technology and output choices in the water demand equation. Estimation results indicate that the price elasticity of agricultural water demand is À0.79, which is greater than that found in previous studies.
Article
Full-text available
Sustainable use of groundwater must ensure not only that the future resource is not threatened by overuse, but also that natural environments that depend on the resource, such as stream baseflows, riparian vegetation, aquatic ecosystems, and wetlands are protected. To properly manage groundwater resources, accurate information about the inputs (recharge) and outputs (pumpage and natural discharge) within each groundwater basin is needed so that the long-term behavior of the aquifer and its sustainable yield can be estimated or reassessed. As a first step towards this effort, this work highlights some key groundwater recharge studies in the Kansas High Plains at different scales, such as regional soil-water budget and groundwater modeling studies, county-scale groundwater recharge studies, as well as field-experimental local studies, including some original new findings, with an emphasis on assumptions and limitations as well as on environmental factors affecting recharge processes. The general impact of irrigation and cultivation on recharge is to appreciably increase the amount of recharge, and in many cases to exceed precipitation as the predominant source of recharge. The imbalance between the water input (recharge) to the High Plains aquifer and the output (pumpage and stream baseflows primarily) is shown to be severe, and responses to stabilize the system by reducing water use, increasing irrigation efficiency, adopting water-saving land-use practices, and other measures are outlined. Finally, the basic steps necessary to move towards sustainable use of groundwater in the High Plains are delineated, such as improving the knowledge base, reporting and providing access to information, furthering public education, as well as promoting better understanding of the publics attitudinal motivations; adopting the ecosystem and adaptive management approaches to managing groundwater; further improving water efficiency; exploiting the full potential of dryland and biosaline agriculture; and adopting a goal of long-term sustainable use.El uso sostenible de aguas subterrneas debe garantizar tanto que el recurso futuro no est amenazado por sobreutilizacin como que los ambientes naturales dependientes del recurso sean protegidos (ie el flujo base de los arroyos, la vegetacin ripariana, los ecosistemas acuticos y los pantanos). El manejo adecuado de los recursos de aguas subterrneas requiere informacin precisa con respecto a los influjos (recarga) y descargas (bombeo y descarga natural) en cada cuenca de aguas subterrneas de tal manera que se pueda estimar o reevaluar el comportamiento de largo plazo del acufero y su tasa de sotenibilidad. En un primer paso hacia esta meta, este trabajo destaca algunos estudios claves de recarga de aguas subterrneas en las llanuras altas de Kansas. Dichos estudios se concentran en diferentes escalas: estudios regionales del presupuesto para aguas del suelo y modelos de aguas subterrneas, estudios de recarga de aguas subterrneas a nivel provincial y estudios locales experimentales de terrenos que incluyen algunos interesantes descubrimientos nuevos. Estas investigaciones comparten el nfasis en los presupuestos de partida y las limitaciones as como en los factores ambientales que afectan los procesos de recarga. El impacto general de las irrigaciones y cultivos sobre la recarga es un obvio incremento en el monto de recarga y en muchos casos excede a la precipitacin como la fuente principal de recarga. Se puede observar que el desequilibrio entre el influjo de agua (recarga) del acufero de las llanuras altas y la descarga (bombeo y flujos base de los arroyos principalmente) es severo. Asimismo, se describen las respuestas para estabilizar el sistema a travs de la reduccin del uso de agua por medio del incremento de la eficiencia de las irrigaciones y de la adopcin de las prcticas de ahorro de agua y del uso de tierras as como otras medidas adicionales. Finalmente se describen los pasos bsicos necesarios para evolucionar hacia el uso sostenible de las aguas subterrneas en las llanuras altas de Kansas. Estos pasos estn constituidos por una mejora del conocimiento base, comunicar y proporcionar fcil acceso a la informacin, mejorar el conocimiento pblico general as como promover un mejor entendimiento de las motivaciones para las actitudes de la comunidad, adoptar los enfoques administrativos de ecosistemas y administracin adaptable en el manejo de las aguas subterrneas, continuar las mejoras del uso eficiente del agua, explotar el potencial de la agricultura de terrenos ridos y biosalina y adoptar como meta el uso sostenible a largo plazo.Lutilisation durable de leau souterraine doit permettre non seulement que la prennit de leau ne soit pas menace, mais aussi que les environnements naturels qui dpendent de cette ressource, tels que la vgtation riveraine, les cosystemes aquatiques et les milieux humides, soient protgs. Afin dassurer une gestion approprie des ressources en eau souterraine, une information prcise concernant les entres (recharge) et les sorties (dcharge naturelle et pompage) deau dans chacun des bassins est ncessaire afin que le comportement long terme de laquifre et le taux de pompage durable puissent tre estims. En guise dinitiative, ce travail illustre certaines tudes cl concernant la recharge de leau souterraine plusieurs chelles dans les hautes plaines du Kansas. Ces tudes comprennent le bilan sol-eau et la modlisation numrique lchelle rgionale, ltude de la recharge des nappes souterraines lchelle du comt, des tudes exprimentales petite chelle et certaines dcouvertes originales. Lors de la prsentation de ces tudes, lemphase est porte sur les hypothses et limitations ainsi que sur les facteurs environmentaux qui affectent les processus de recharge. En gnral, les effets de lirrigation et de lagriculture sur la recharge sont daugmenter considrablement le taux de recharge, et dans plusieurs cas, dexcder les prcipitations comme principale source de recharge. Le dsquilibre entre les intrants deau (recharge) et entrants (pompage et coulement de base dans les rivires) dans laquifre des hautes plaines est trs important. Les rsultats des efforts de stabilisation du systme aquifre en diminuant lutilisation deau, en amliorant lefficacit des techniques dirrigation, en adoptant des pratiques dutilisation du territoire qui rduisent lutilisation deau et en adoptant certaines autres mesures sont prsents. Enfin, les tapes de base ncessaires afin datteindre une utilisation durable de leau souterraine dans les hautes plaines sontexposes. Elles comprennent lamlioration des connaissance de base, lapromotion dune meilleure comprhension de la motivation et de lattitudedu public, ladoption dune approche de gestion de leau souterraineadaptable et base sur les cosystmes, lamlioration de lefficacitdutilisation de leau, lexploitation du plein potentiel de lagriculturebiosaline et en milieu aride, et ladoption dun objectif pourlutilisation durable long terme.
Article
Full-text available
We use the geo-referenced June Agricultural Survey of the U.S. Department of Agriculture to match values of individual farms in California with a measure of water availability as mediated through irrigation districts, and degree days, a nonlinear transformation of temperature, controlling for other influences on value such as soil quality, to examine the potential effects of climate change on irrigated agriculture in California. Water availability strongly capitalizes into farmland values. The predicted decrease in water availability in the latest climate change scenarios downscaled to California can therefore be expected to have a significant negative impact on the value of farmland.
Article
Full-text available
The United States produces 41% of the world's corn and 38% of the world's soybeans. These crops comprise two of the four largest sources of caloric energy produced and are thus critical for world food supply. We pair a panel of county-level yields for these two crops, plus cotton (a warmer-weather crop), with a new fine-scale weather dataset that incorporates the whole distribution of temperatures within each day and across all days in the growing season. We find that yields increase with temperature up to 29 degrees C for corn, 30 degrees C for soybeans, and 32 degrees C for cotton but that temperatures above these thresholds are very harmful. The slope of the decline above the optimum is significantly steeper than the incline below it. The same nonlinear and asymmetric relationship is found when we isolate either time-series or cross-sectional variations in temperatures and yields. This suggests limited historical adaptation of seed varieties or management practices to warmer temperatures because the cross-section includes farmers' adaptations to warmer climates and the time-series does not. Holding current growing regions fixed, area-weighted average yields are predicted to decrease by 30-46% before the end of the century under the slowest (B1) warming scenario and decrease by 63-82% under the most rapid warming scenario (A1FI) under the Hadley III model.
Article
Full-text available
Naturally occurring long-term mean annual base recharge to ground water in Nebraska was estimated with the help of a water-balance approach and an objective automated technique for base-flow separation involving minimal parameter-optimization requirements. Base recharge is equal to total recharge minus the amount of evapotranspiration coming directly from ground water. The estimation of evapotranspiration in the water-balance equation avoids the need to specify a contributing drainage area for ground water, which in certain cases may be considerably different from the drainage area for surface runoff. Evapotranspiration was calculated by the WREVAP model at the Solar and Meteorological Surface Observation Network (SAMSON) sites. Long-term mean annual base recharge was derived by determining the product of estimated long-term mean annual runoff (the difference between precipitation and evapotranspiration) and the base-flow index (BFI). The BFI was calculated from discharge data obtained from the U.S. Geological Survey's gauging stations in Nebraska. Mapping was achieved by using geographic information systems (GIS) and geostatistics. This approach is best suited for regional-scale applications. It does not require complex hydrogeologic modeling nor detailed knowledge of soil characteristics, vegetation cover, or land-use practices. Long-term mean annual base recharge rates in excess of 110 mm/year resulted in the extreme eastern part of Nebraska. The western portion of the state expressed rates of only 15 to 20 mm annually, while the Sandhills region of north-central Nebraska was estimated to receive twice as much base recharge (40 to 50 mm/year) as areas south of it.
Article
Full-text available
Naturally occurring long-term mean annual recharge to ground water in Nebraska was estimated by a novel water-balance approach. This approach uses geographic information systems (GIS) layers of land cover, elevation of land and ground water surfaces, base recharge, and the recharge potential in combination with monthly climatic data. Long-term mean recharge > 140 mm per year was estimated in eastern Nebraska, having the highest annual precipitation rates within the state, along the Elkhorn, Platte, Missouri, and Big Nemaha River valleys where ground water is very close to the surface. Similarly high recharge values were obtained for the Sand Hills sections of the North and Middle Loup, as well as Cedar River and Beaver Creek valleys due to high infiltration rates of the sandy soil in the area. The westernmost and southwesternmost parts of the state were estimated to typically receive < 30 mm of recharge a year.
Article
This study provides an estimate of the gross value of irrigation water from the U.S. High Plains Aquifer. We estimate a yield function for aggregated crop biomass production, based on countylevel observations for 1960–2007. This study found that irrigation increases total biomass yield in this region by an average of 51%. We estimate the average gross annual value of irrigation as of 2007 to be $196 per acre, for a total of about $3 billion across the aquifer. We also estimate that on average across the aquifer, exposure to 24 hours of temperatures above 33�C (one degree day) reduces biomass yield by 3%, with a value in 2007 of about $10 per acre.
Article
This article presents a new method for estimating changes in depth to groundwater at a yearly, county level and incorporates these estimates as the dependent variable of econometric models for the High Plains aquifer. The High Plains (Ogallala) aquifer underlies eight states in the central United States and is the primary source of irrigation water for this large food producing region. The stock of groundwater is a finite, non-renewable resource with minimal recharge in most areas. Many fields of study, including hydrology and agricultural economics, are interested in depth to groundwater changes because they serve as a proxy for estimating groundwater stock changes. Economic data exist at the yearly, county level, but there are currently no yearly estimates for depth to groundwater changes making it difficult to reliably utilize economic optimization and production models that depend on groundwater data. Including the new estimates generated in this study as the dependent variable with climate, recharge, and irrigation as independent variables in panel econometric models (Pooled OLS, Random Effects, and Fixed Effects) with counties as the individuals produced statistically significant results. Further, models were found which consistently performed best when comparing coefficients and predicted values with outside estimates from hydrology studies. Advisor: Lilyan E. Fulginiti
Article
An 8-week feeding trial was conducted to evaluate the effects of fish meal (FM) replacement by rice protein concentrate (RPC) with supplementation of microcapsule lysine (ML) or crystalline lysine (CL) on growth performance, muscle development and flesh quality of blunt snout bream. Four isonitrogenous and isoenergetic diets were formulated, including FM diet (containing 50 g/kg FM), RPC diet (FM replaced by RPC), MRPC diet (FM replaced by RPC with ML supplementation) and CRPC diet (FM replaced by RPC with CL supplementation). Fish fed FM diet had significantly higher weight gain, feed efficiency, protein efficiency ratio and nitrogen and energy utilization than that of RPC group, but showed no statistical difference with other treatments. In addition, fish fed RPC diet showed higher muscle fibre frequency in the 20- to 50-μm class but lower >50-μm class and higher cooking loss than that of the other groups. Furthermore, no significant difference was found in whole-body proximate compositions, frequency distribution of <20-μm-diameter fibres, texture, muscle content, collagen, pH 24 hr post-mortem and sensory quality. The results showed that RPC supplemented with ML or CL could replace fishmeal without any adverse effects on growth performance and flesh quality for blunt snout bream.
Article
Measurement errors in both human and natural components of agricultural and environmental systems can be as much a source of estimation bias as omitted variables, selfselection, simultaneity, and reverse causality. Nonetheless, partly because of difficulties in obtaining data, there is less literature on measurement error problems than on other endogeneity problems. This article examines estimation bias in the price elasticity of groundwater consumption for irrigated agriculture on the intensive margin. The price at issue is for the energy used in pumping and pressurizing water for delivery. Lacking the precise unit irrigation cost, previous studies imputed irrigation costs. We first consider groundwater irrigation costs and identify factors that can cause measurement errors in the process of imputation under incomplete information about the determinants of irrigation costs. We follow this by systematically analyzing the potential bias caused by measurement errors, using econometric theory along with Monte Carlo simulations where appropriate. We then quantify actual measurement errors, making use of a unique dataset in which energy and groundwater consumption data are matched for individual observations. Finally, we compare regression results using exact irrigation costs as opposed to imputed ones. We find evidence of substantial measurement errors resulting in attenuation and amplification bias in the price elasticity of irrigation water consumption on the intensive margin. Our results indicate that measurement errors in irrigation costs can lead to misleading policy implications related to water and energy pricing as a tool to conserve water. We also show that estimating the energy price elasticity of groundwater use is not as straightforward as previously thought.
Article
The increment in food prices observed in recent years drew the attention of researchers and policymakers to the long term capacity of the world to feed itself in the near future. While it is estimated that an additional 30 percent increase in the world population and higher incomes will double food demand by 2050, several studies indicated that the growth rate of agricultural productivity in the developed world has been slowing down. The food production increases needed to satisfy future demand will put greater stress on existing cropland and natural resources. As an additional source of concern, several studies estimate that climate change is likely to aggravate the situation. ^ Chapter 1 analyzes trends in agricultural productivity growth in South America, a region that is likely to have a major role in fulfilling the increased future food demand, to investigate if the slowdown being observed in other regions is present in the subcontinent. Additionally, we study how the institutional, economical and sociological environment affects agricultural productivity. ^ Chapter 2 studies the impact of climate on agricultural productivity for 101 counties in Nebraska and Iowa for the 1960-2008 period by developing a county level biomass production function that in addition to the climatic variables it also considers human inputs, soil organic matter and percentage of irrigated land. The production function is jointly estimated with farmers’ demand equations for fertilizers and chemicals to account for farmers’ profit maximizing behavior. ^ Chapter 3 inspects agricultural production survey data for more than 30,000 farms in Nebraska during the period 2004-2011 to estimate a corn yield production function that approximates the impact of climate on agricultural productivity and the effect of water from irrigation. The inclusion of irrigation is of particular importance, since it allows studying its use as a source of heat mitigation and productivity enhancer. As in chapter two, the production function is jointly estimated with human inputs cost share equations to account for the farmers’ profit maximizing behavior.
Article
We examine the effects of energy prices on groundwater extraction using an econometric model of a farmer's irrigation water pumping decision that accounts for both the intensive and extensive margins. Our results show that energy prices have an effect on both types of margins. Increasing energy prices would affect crop selection decisions, crop acreage allocation decisions, and farmers’ demand for water. Our estimated total marginal effect, which sums the effects on the intensive and extensive margins, suggests that a $1 per million btu increase in the energy price would decrease water extraction by an individual farmer by 5.89 acre-feet per year, a decrease of 3.6 percent of the average annual extraction rate. Our estimated elasticity of water extraction with respect to energy price is −0.26.
Article
The major driver of water-level changes in many heavily stressed aquifers is irrigation pumping, which is primarily a function of meteorological conditions (precipitation and potential evapotranspiration). Correlations among climatic indices, water-level changes, and pumping can thus often be used to assess the impact of climatic and anthropogenic stresses. The power of this simple, first-order approach, which captures the primary excitation-response relationships driving aquifer behavior, is demonstrated for the High Plains aquifer in the central United States (Kansas). Regional correlations between water-level changes and climatic indices indicate a repeat of the most severe drought on record would more than double water-level decline rates. More importantly, correlations between water-level changes and reported pumping reveal that practically feasible pumping reductions should stabilize water levels, at least temporarily, over much of the aquifer in Kansas. This example illustrates that when uncertainty obscures process-based modeling projections, simple approaches such as described here can often provide insights of great practical value.
Technical Report
Estimates of water use in the United States indicate that about 408 billion gallons per day (one thousand million gallons per day, abbreviated Bgal/d) were withdrawn for all uses during 2000. This total has varied less than 3 percent since 1985 as withdrawals have stabilized for the two largest uses?thermoelectric power and irrigation. Fresh ground-water withdrawals (83.3 Bgal/d) during 2000 were 14 percent more than during 1985. Fresh surface-water withdrawals for 2000 were 262 Bgal/d, varying less than 2 percent since 1985. About 195 Bgal/d, or 48 percent of all freshwater and saline-water withdrawals for 2000, were used for thermoelectric power. Most of this water was derived from surface water and used for once-through cooling at power plants. About 52 percent of fresh surface-water withdrawals and about 96 percent of saline-water withdrawals were for thermoelectric-power use. Withdrawals for thermoelectric power have been relatively stable since 1985. Irrigation remained the largest use of freshwater in the United States and totaled 137 Bgal/d for 2000. Since 1950, irrigation has accounted for about 65 percent of total water withdrawals, excluding those for thermoelectric power. Historically, more surface water than ground water has been used for irrigation. However, the percentage of total irrigation withdrawals from ground water has continued to increase, from 23 percent in 1950 to 42 percent in 2000. Total irrigation withdrawals were 2 percent more for 2000 than for 1995, because of a 16-percent increase in ground-water withdrawals and a small decrease in surface-water withdrawals. Irrigated acreage more than doubled between 1950 and 1980, then remained constant before increasing nearly 7 percent between 1995 and 2000. The number of acres irrigated with sprinkler and microirrigation systems has continued to increase and now comprises more than one-half the total irrigated acreage. Public-supply withdrawals were more than 43 Bgal/d for 2000. Public-supply withdrawals during 1950 were 14 Bgal/d. During 2000, about 85 percent of the population in the United States obtained drinking water from public suppliers, compared to 62 percent during 1950. Surface water provided 63 percent of the total during 2000, whereas surface water provided 74 percent during 1950. Self-supplied industrial withdrawals totaled nearly 20 Bgal/d in 2000, or 12 percent less than in 1995. Compared to 1985, industrial self-supplied withdrawals declined by 24 percent. Estimates of industrial water use in the United States were largest during the years from 1965 to 1980, but during 2000, estimates were at the lowest level since reporting began in 1950. Combined withdrawals for self-supplied domestic, livestock, aquaculture, and mining were less than 13 Bgal/d for 2000, and represented about 3 percent of total withdrawals. California, Texas, and Florida accounted for one-fourth of all water withdrawals for 2000. States with the largest surface-water withdrawals were California, which had large withdrawals for irrigation and thermoelectric power, and Texas, which had large withdrawals for thermoelectric power. States with the largest ground-water withdrawals were California, Texas, and Nebraska, all of which had large withdrawals for irrigation.
Article
Agricultural groundwater use is increasingly being restricted to address the negative impacts of pumping on instream flows for downstream users, endangered species habitat, and recreation. Understanding the spatial heterogeneity of the costs of water use restrictions to farmers is critical to evaluating the effectiveness of current and alternative water management policies. We use a geospatial population dataset of irrigation wells in the Republican River Basin of Nebraska and model the simultaneous crop choice, land and water use decisions at a well level. We estimate the magnitude and distribution of costs of current groundwater restrictions as well as cost savings from alternative market-based policies that allow trading of permits between farmers. Our analysis highlights the importance of the initial distribution of permits and the institutional context in which trading occurs. Both allocated but unused permits and land estimated to move from irrigated to dryland crops provide important trading volume into the water rights market. The results show that the cost savings from allowing trading of groundwater pumping rights are distributed unevenly between wells, counties, and groundwater management institutions.
Article
I studied the impact that high temperatures have over the agricultural performance for countries in Nebraska.
Article
The High Plains aquifer underlies about 174,000 square miles in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The aquifer is the principal source of water for irrigation and public supply in this area, which is one of the major agricultural areas in the United States. However, soon after groundwater irrigation began, water-level declines occurred in some parts of the aquifer. In response, the U.S. Geological Survey, in cooperation with numerous Federal, State, and local water-resource agencies, began monitoring groundwater levels in the aquifer. Water levels are measured primarily in irrigation wells. The wells are measured annually in winter to early spring (generally January to May, depending on location), when water levels generally have recovered from groundwater pumping for irrigation in the previous growing season and before the current year's irrigation season. Water-level elevation for predevelopment conditions (about 1950) was determined using water-level measurements from more than 20,000 wells. Water-level elevation for 2007 was measured in more than 9,000 wells. The water-level measurements were analyzed and interpolated to map discrete intervals of water-level changes from predevelopment to the year 2007. The change in the volume of drainable water stored in the aquifer was calculated using the mapped area of each water-level-change interval, the average water-level change within each mapped interval, and the estimated average specific yield for the aquifer. Water-level changes in the aquifer from predevelopment to 2007 ranged between a rise of +84 feet for a well in Nebraska and a decline of -234 feet for a well in Texas. Area-weighted, average water-level change in the aquifer was a decline of -14 feet from predevelopment to 2007. Total water in storage in the aquifer in 2007 was about 2.9 billion acre-feet, a decline of about 270 million acre-feet (or 9 percent) since predevelopment.
Article
We investigate the behavior of farmers who share an underground aquifer. In the case where seepage may occur the resource is nonexclusive, giving rise to a spatial externality whereby pumping by one user affects others nearby. Theoretically, these externalities are potentially important causes of welfare loss. Using a unique spatial data set of groundwater users in western Kansas, we are able to empirically measure the physical and behavioral effects of groundwater pumping by neighbors. To address the simultaneity of neighbors' pumping, we use the neighbors' permitted water allocation as an instrument for their pumping. We estimate that 2.5% of the total groundwater extracted each year in western Kansas is over-extraction due to the effects of spatial externalities. Individuals who own multiple wells internalize their own externality by trading off pumping at one well for pumping at another.
Article
Groundwater pumping can reduce the flow of surface water in nearby streams. In the United States, recent awareness of this externality has led to intra- and inter-state conflict and rapidly-changing water management policies and institutions. Although the marginal damage of groundwater use on stream flows depends crucially on the location of pumping relative to streams, current regulations are generally uniform over space. We use a population data set of irrigation wells in the Nebraska portion of the Republican River Basin to analyze whether adopting spatially differentiated groundwater pumping regulations leads to significant reductions in farmer abatement costs and costs from damage to streams. We find that regulators can generate most of the potential savings in total social costs without accounting for spatial heterogeneity. However, if regulators need to increase the protection of streams significantly from current levels, spatially differentiated policies will yield sizable cost savings.
Article
The southeastern United States typically receives more than 130cm of precipitation per year. In this region, as in others around the world, irrigation is used as a supplement to rainfall. Over the past thirty years the number of hectares under irrigation in the region has grown considerably, as has population. Policy makers are currently searching for effective tools to address water demand. This study tests the effect of water costs, crop prices and technology on the multiple crop production decision using supplemental irrigation. Results for Georgia row crop producers indicate water demand is modestly affected by water price (with elasticities between -0.01 and -0.17), but more so by crop price (with elasticities between 0.5 and 0.82). Results also suggest adoption of lower pressure irrigation systems does not necessarily lead to lower water application rates on corn, cotton, peanuts, and soybeans.
Article
Applying a model of the multioutput firm, econometric results are reported for irrigated production in four multistate regions of the American West. Cross-sectional microdata from the Farm and Ranch Irrigation Survey and limited-dependent variable methods are used to estimate crop-choice, supply, land allocation, and water demand functions for field crops. Farm-level water demand is decomposed into the sum of crop-level water demands, and crop-level demands are further separated into an extensive margin (land allocations) and intensive margin (short-run water use). Response to water price (measured as groundwater pumping cost) occurs primarily at the extensive margin.
Article
We link farmland values to climatic, soil, and socioeconomic variables for U.S. counties east of the 100th meridian, the historical boundary of agriculture not primarily dependent on irrigation. Degree days, a nonlinear transformation of the climatic variables suggested by agronomic experiments as more relevant to crop yield, gives an improved fit and increased robustness. Estimated coefficients are consistent with the experimental results. The model is employed to estimate the potential impacts on farmland values for a range of recent warming scenarios. The predictions are very robust, and more than 75% of the counties in our sample show a statistically significant effect, ranging from moderate gains to large losses, with losses in the aggregate that can become quite large under scenarios involving sustained heavy use of fossil fuels. Copyright (c) 2006 The President and Fellows of Harvard College and the Massachusetts Institute of Technology.
Article
Most existing economic analyses of optimal groundwater management use single-cell aquifer models, which assume that an aquifer responds uniformly and instantly to groundwater pumping. This paper demonstrates how spatially explicit aquifer response equations from the water resources engineering literature may be embedded in a general economic framework. Calibration of our theoretical model to published economic studies of specific aquifers demonstrates that, by averaging basin drawdown across the entire resource, existing studies generally understate the magnitude of the groundwater pumping externality relative to spatially explicit models. For the aquifers studied, the drawdown predicted by single-cell models may be orders of magnitude less than that predicted by a spatially explicit model, even at large distances from a pumping well. Our results suggest that single-cell models may be appropriate for analyses of the welfare effects of groundwater management policies either in small aquifers or in larger aquifers where average well spacings are tens of miles or more. However, in extensive aquifers where well spacings are on the order of a few miles or less, such as many of those of concern to groundwater managers and policy makers, use of single-cell models may result in misleading policy implications due to understatement of the magnitude and spatial nature of the groundwater externality.
Comparing Irrigation Energy Costs. Kansas: Kansas State University Agricultural Experiment Station and Cooperative Extension Service Manhattan
  • D Rogers
  • M Alam
Rogers, D., and M. Alam. 2006. Comparing Irrigation Energy Costs. Kansas: Kansas State University Agricultural Experiment Station and Cooperative Extension Service Manhattan. http://itc.ta mu.edu/documents/extensionpubs/Kansas%20State/MF2360.pdf.
The Future of Groundwater Management in the High Plains: Evolving Institutions, Aquifers and Regulations
  • Schoengold K.
Schoengold, K., and N. Brozovi c. 2018. "The Future of Groundwater Management in the High Plains: Evolving Institutions, Aquifers and Regulations." Western Economics Forum 16 (1): 47-53.
Maupin, M.A., J.F. Kenny, S.S. Hutson, J.K. Lovelace, N.L. Barber, and K.S. Linsey. 2014. “Estimated Use of Water in the United States in 2010.” U.S. Geological Survey Circular 1405. <https://doi.org/10.3133/cir1405>
McGuire, V.L.2014. “Water‐Level Changes and Change in Water in Storage in the High Plains Aquifer, Predevelopment to 2013 and 2011–13.” U.S. Geological Survey Scientific Investigations Report 2014–5218, <https://doi.org/10.3133/sir20145218>
Shafer, M., D. Ojima, J.M. Antle, D. Kluck, R.A. McPherson, S. Petersen, B. Scanlon, and K. Sherman.2014. “Great Plains.” Climate Change Impacts in the United States: The Third National Climate Assessment. Ch. 19 in U.S. Global Change Research Program, 441–61. <https://doi.org/10.7930/J0D798BC>
Understanding and Assessing Climate Change University of Nebraska-Lincoln Implications for Nebraska”. In A Synthesis Report to Support Decision Making and Natural Resource Management in a Changing Climate
  • D J R J Bathke
  • C M Oglesby
  • . A Rowe
  • Wilhite
Bathke, D.J., R. J. Oglesby, C. M. Rowe, and D. A. Wilhite. 2014. "Understanding and Assessing Climate Change University of Nebraska-Lincoln Implications for Nebraska". In A Synthesis Report to Support Decision Making and Natural Resource Management in a Changing Climate. University of Nebraska-Lincoln. http://snr.unl.edu/download/research/projects/climateimpac ts/2014ClimateChange.pdf.
Groundwater Laws across the Ogallala Aquifer Region
  • B B Guerrero
  • K Golden
  • J Schoengold
  • A Suter
  • C Stoecker
  • Goemans
  • Manning
Guerrero, B., B. Golden, K. Schoengold, J. Suter, A. Stoecker, C. Goemans, and D. Manning. 2017. "Groundwater Laws across the Ogallala Aquifer Region." Colorado Water (November/December 2017).
Regional Climate Trends and Scenarios for the US National Climate Assessment: Part 4. Climate of the U.S. Great Plains
  • K E Kunkel
  • L E Stevens
  • S E Stevens
  • L Sun
  • E Janssen
  • D Wuebbles
  • M C Kruk
Kunkel, K.E., L.E. Stevens, S.E. Stevens, L. Sun, E. Janssen, D. Wuebbles, M.C. Kruk, et al.2013. "Regional Climate Trends and Scenarios for the US National Climate Assessment: Part 4. Climate of the U.S. Great Plains." NOAA Technical Report NES-DIS 142, no. 7: 60.
Great Plains.” Climate Change Impacts in the United States: The Third National Climate Assessment. Ch. 19 in U.S. Global Change Research Program 441-61
  • M D Shafer
  • J M Ojima
  • D Antle
  • R A Kluck
  • S Mcpherson
  • B Petersen
  • Scanlon
  • Sherman
Statistical Modeling and of Hydrology in the High plains Aquifer: A Pilot Study inNebraska
  • E R Rubin
  • Perrin
  • Fulginiti
Rubin, E., R. Perrin, and L. Fulginiti. 2014. "Statistical Modeling and of Hydrology in the High plains Aquifer: A Pilot Study inNebraska." Department of Agricultural Economics Working Paper, University of Nebraska, Lincoln.
  • R G Niswonger
  • D E Prudic
  • R S Regan
Niswonger, R.G., D.E. Prudic, and R.S. Regan. 2006. "Documentation of the Unsaturated-Zone Flow (UZF1) Package for Modeling Unsaturated Flow between the Land Surface and the Water Table with MODFLOW-2005." U.S. Geological Survey Techniques and Methods 6-A19, 62 pp.
Climate Change Impacts in the United States: The Third National Climate Assessment. Ch. 19 in U.S. Global Change Research Program
  • M Shafer
  • D Ojima
  • J M Antle
  • D Kluck
  • R A Mcpherson
  • S Petersen
  • B Scanlon
  • K Sherman
Shafer, M., D. Ojima, J.M. Antle, D. Kluck, R.A. McPherson, S. Petersen, B. Scanlon, and K. Sherman.2014. "Great Plains." Climate Change Impacts in the United States: The Third National Climate Assessment. Ch. 19 in U.S. Global Change Research Program, 441-61. https://doi.org/10.7930/J0D798BC.