Your search found 10 records
1 Llamas, R.; Back, W.; Margat, J. 1992. Groundwater use: Equilibrium between social benefits and potential environmental costs. Applied Hydrogeology, 1(2):3-14.
(Location: IWMI-HQ Call no: P 4074 Record No: H017497)
(1.33 MB)
2 Khosla, R.; Garcia, L. 2001. Using GIS technologies to monitor the Ogallala Aquifer. Colorado Water Newsletter, 18(1):13-14.
(Location: IWMI-HQ Call no: P 5658 Record No: H027737)
(Location: IWMI-HQ Call no: PER Record No: H030190)
4 Al-Kaisi, M. M.; Yin, X. 2003. Effects of nitrogen rate, irrigation rate, and plant population on corn yield and water use efficiency. Agronomy Journal, 95:1475-1482.
(Location: IWMI-HQ Call no: P 7045 Record No: H035599)
(0.08 MB)
5 Peterson, J. M.; Ding, Y. 2005. Economic adjustments to groundwater depletion in the High Plains: Do water-saving irrigation systems save water? American Journal of Agricultural Economics, 87:147-159.
(Location: IWMI-HQ Call no: P 7155 Record No: H036336)
6 Kurz, B.; Seelan, S. 2009. Use of remote sensing to map irrigated agriculture in areas overlying the Ogallala aquifer, United States. In Thenkabail, P. S.; Lyon, J. G.; Turral, H.; Biradar, C. M. (Eds.). Remote sensing of global croplands for food security. Boca Raton, FL, USA: CRC Press. pp.199-215. (Taylor & Francis Series in Remote Sensing Applications)
(Location: IWMI HQ Call no: 631.7.1 G000 THE Record No: H042423)
7 Closas, Alvar; Molle, Francois. 2016. Groundwater governance in America. [Project report of the Groundwater Governance in the Arab World - Taking Stock and Addressing the Challenges]. Colombo, Sri Lanka: International Water Management Institute (IWMI). 238p. (Groundwater Governance in the Arab World - Report 5)
(Location: IWMI HQ Call no: e-copy only Record No: H048400)
(7.73 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H049527)
(15.40 MB)
Groundwater models are often used to assess the impact of climate or management strategies on groundwater resources in arid and semiarid regions of the world. However, these models do not account for crop growth and crop yield, and thus cannot be used for evaluating long-term impacts of climate and management strategies on water use efficiency and farm profitability of agricultural systems while managing the aquifers sustainably. This study presented a linkage between DSSAT, an agronomic model, and MODFLOW, a groundwater flow model. The linkage between these two models occurred on an annual basis, with rates of irrigation and deep percolation from an ensemble of field-scale DSSAT simulations converted to pumping rates and recharge rates for the MODFLOW simulation. MODFLOW simulated groundwater head, which can be used to update saturated thickness and thereby well capacities for each pumping well in the model domain. Simulated well capacities were then used to constrain irrigation applications in the DSSAT simulations during the following growing season. Python scripts were used to convert output from one model to input files for the other model. The DSSAT-MODFLOW modeling system was applied to the Ogallala aquifer underlying Finney County, Kansas, a region experiencing significant groundwater depletion due to irrigation practices, and was tested against observed water table elevation and crop yield. Over a decadal period, well capacity decreased by > 50 % for many pumping wells in the county. A no-irrigation scenario for this same time period resulted in average water table elevation increasing by 2 m, but also a 70 % decline in crop yield. Additional work is needed to balance groundwater conservation with crop yield. The DSSAT-MODFLOW modeling system can be used in regions worldwide to assess changes in irrigation technologies, crop selection, and climate change adaptation strategies.
(Location: IWMI HQ Call no: e-copy only Record No: H049629)
(0.55 MB)
As groundwater levels continue to decline in the Ogallala Aquifer, stakeholders, policymakers, and producers encourage the adoption of new irrigation technology in an effort to conserve groundwater, extend the economic life of the aquifer, and enhance profitability. One such technology currently receiving attention in the Central Ogallala region is the mobile drip irrigation (MDI) application system. This study compares MDI to low elevation spray application irrigation by evaluating the changes in variable cost per hectare to calculate the payback period for a MDI system under three levels of investment cost for grain and fiber crops representing three levels of water use while holding yield constant. Using a 3% discount rate, under the medium level of investment cost ($371 per hectare), a discounted payback period of 4.9, 9.0, and 6.3 years is required for corn, cotton, and sorghum/wheat, respectively. As the cost per hectare to convert an existing center pivot drops to $185 per hectare, the payback period also drops to 2.3, 4.2, and 3.0 years, respectively. Thus, producers growing higher water use crops are able to recover the costs of the conversion to MDI through increased water use efficiency quicker than producers growing medium and lower water use crops.
(Location: IWMI HQ Call no: e-copy only Record No: H052293)
(0.68 MB)
Irrigation water is required for increased crop yield and production to satisfy global food demand. However, irrigation also has negative impacts, including the production of greenhouse gas (GHG) emissions from groundwater pumping. To lessen this environmental problem, management methods that minimize agricultural GHG emissions from groundwater pumping should be identified. This work aims to compare measures that decrease agricultural groundwater withdrawal GHG emissions. A comparison among different energy supply and demand management choices for groundwater pumping was made to identify the most effective measure. Results indicated that the best agricultural groundwater pumping energy management practices are affected by the type of pump (e.g., electric or natural gas operated) and for electric pumps, the electric grid energy mix (e.g., coal, natural gas, oil, wind, solar). Due to their higher operational pump efficiency (OPE), electric pumps consume less energy than natural gas pumps to extract an equal volume of groundwater under similar conditions. Nevertheless, natural gas pumps produce less GHG emissions than electric pumps using the US Central and Southern Plains electricity mix. Hence, groundwater pumping energy demand management through improving the OPE of natural gas pumps will save more GHG emissions (7600 kg CO2-eq year-1) than switching to electric pumps using the electricity mix applied to this study (2800 kg CO2-eq year-1). Additionally, switching to cleaner energy sources (wind and solar) can save significantly higher amounts of carbon than just improving OPE. This analysis can guide policymakers and individuals to assist in meeting global GHG emission reduction goals and targets while satisfying increasing food demand.
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