Progress 10/01/99 to 09/30/04
Outputs
A two-dimensional physically based infiltration model was developed for furrow irrigation. Infiltration was simulated using the Green-Ampt infiltration method. Simulation tests showed that the two-dimensional model was capable of estimating cumulative infiltration volume within 8 percent compared to simulated infiltration using a much more complex and data intensive finite element model, Hydrus-2D. Application of the two-dimensional model allows irrigation performance parameters to be predicted using input parameter estimates that are more readily available on a field scale. An evaluation of nitrate pollution of groundwater in Central Nebraska found that water quality had improved slightly on land that had been converted to center pivots, whereas there was no observed improvement beneath the furrow irrigated fields from 1988 to 1997. A study of management options for reducing nitrate pollution in irrigated areas found that nitrate pollution of groundwater could be most
efficiently reduced by decreasing the amount of nitrogen and water applied, by shifting from gravity to sprinkler systems and by producing more alfalfa and less corn. When starting with groundwater containing 30 mg/l of nitrate nitrogen, the annualized per acre cost of improvement over a 50 year improvement plan ranged from about $3.50 per mg change in concentration for the first few units to over $100 per mg as concentration approached the public health standard of 10 mg/l. An analysis of the economics of augmenting stream flow through reduced groundwater pumping in the Republican Basin found that it would be much more efficient to place controls on consumptive use rather than gross water pumped. The per acre foot cost of augmenting stream flow was 43 percent lower if it was achieved with a policy which directly limited consumptive use, instead of the more common approach of limiting water pumped. A second price, sequential auction model for deciding who will supply environmental
water to the Platte River was developed. With this model the participating states bid sequentially to supply the water in 10,000 acre-foot blocks, with bids starting high and working down until no one was willing to reduce the bid price any further. The simulated results satisfy standard efficiency conditions, but suggest that a substantial premium above real supply costs will be required to induce the states with the least cost water to supply more than their proportional share. Another study investigated the use of game theory models for resolving disputes over how much water should be allocated to the protection of threatened and endangered species, who should supply it and who should pay for it. Three models were developed: Utilitarian, Nash and Egalitarian. The results suggest that if the bargaining agents were not concerned about equity between interest groups they would adopt a policy of adaptive management, investing from one-fourth to one-half of the U.S. Fish and Wildlife
Service request, with a significant contribution from the private sector.
Impacts
The results from irrigation management and water quality studies are contributing to more widespread use of best management practices and to improved water quality policy. Both the amount of nitrogen and the amount of water applied to crops has been decreasing in the major irrigated areas where water quality has been a problem. The auction and bargaining models developed and applied to the Platte Basin identify the terms of a water allocation agreement which are most likely to be acceptable to all major parties, including Colorado, Nebraska, and the U.S. Department of Interior. These findings may facilitate reaching a settlement in an endangered species, water allocation dispute that has been on-going for over 25 years at a cost of several million dollars.
Publications
- Supalla, Raymond J. et al. 2004. Chapter 12, Seeking Solutions for Interstate Conflict Over Water and Endangered Species: Platte River Watershed, in "Economics and Ecologocial Risk Assessment: Applications to Watershed Management," Edited by Bruins and Heberling, CRC Press.
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Progress 10/01/02 to 09/30/03
Outputs
Work was completed this year on the use of game models for resolving disputes over the allocation of Platte river water. The dispute involves disagreements over how much water should be allocated to the protection of threatened and endangered species, who should supply it, Colorado, Nebraska or Wyoming, and who should pay for it. Three models were developed: Utilitarian, Nash and Egalitarian. The final results suggest that if the bargaining agents were not concerned about equity between interest groups they would adopt a policy of adaptive management, investing one-fourth to one-half the USFWS request, with a significant contribution from the private sector. However, if equity was more of a concern, the solution would involve a similar approach, but with a slightly higher investment in endangered species protection. Production function and hydrology data have been compiled for use in a restricted-equilibrium model of the Platte River system, in cooperation with
Colorado State University and ERS, USDA. The first version of this model will be used to analyze the economic impact of short-term within season reductions in the available surface water supply. Subsequent versions of the model will be used to assess the consequences of longer term adjustments in water supplies.
Impacts
The bargaining models developed for the Platte River identify the terms of a water allocation agreement that is most likely to be acceptable to all major parties, including Colorado, Nebraska, and the U.S. Department of Interior. These findings may facilitiate reaching a settlement in an endangered species,water allocation dispute that has been on-going for over 25 years at a cost of several million dollars.
Publications
- Supalla, Raymond J., 2003. Irrigation Management Research Needs in an Era of Changing Water Use Priorities, Current Agriculture, Food and Resource Issues, Canadian Agricultural Economics Society, published electronically.
- Supalla, Raymond J. 2003. Institutional Arrangements to Improve Water Quality in Irrigated Agriculture, International Journal of Water Resources Development, V.19, No. 2.
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Progress 10/01/01 to 09/30/02
Outputs
One recently completed project found that nitrate pollution of groundwater could be most efficiently reduced by decreasing the amount of nitrogen and water applied, by shifting from gravity to sprinkler systems and by producing more alfalfa and less corn. When starting with groundwater containing 30 parts per million (ppm) of nitrate nitrogen, the annualized cost of improvement over a 50 year improvement plan ranged from about $3.50 per acre per one ppm change in concentration for the first few units of improvement to over $100 per ppm as concentration approached the public health standard of 10 ppm. Actions to prevent pollution of groundwater or to produce slight improvements in already polluted water were found to be financially feasible within a 50-year time frame. Returning seriously polluted groundwater to a level at or below the public health standard, however, is probably not feasible unless one thinks in terms of plans that take much longer than 50 years.
Another study produced a two-dimensional physically based infiltration model for simulating furrow irrigation. Simulation tests showed that a two-dimensional model, using the Green-Ampt infiltration method, was capable of estimating cumulative infiltration volume within 8% compared to simulated infiltration using a much more complex and data intensive finite element model, Hydrus-2D. Techniques developed in this study will help other scientists improve the accuracy of furrow irrigation models using imput parameter estimates that are readily available on a field scale. Work also continued this year on a third study which focused on the development of game models for resolving disputes over the allocation of water in the Middle Platte region. The dispute involves disagreements over how much water should be allocated to the protection of threatened and endangered species, who should supply it, Colorado, Nebraska or Wyoming, and who should pay for it. Mail survey data were used to develop
bargaining models for investigating potential solutions to the Platte Basin conflicts. Three models were developed: Utilitarian, Nash and Egalitarian. The results suggest that if the bargaining agents were not concerned about equity between interest groups they would adopt an adaptive management approach which meets only some of the endangered species needs, spending about $10M per year with the costs split evenly between the federal government, the states and private environmental groups. However, if equity rather than total utility was more of a concern, the solution would involve no state contribution to program costs. This finding appears to reflect a strongly held view that endangered species protection is a national concern that should be supported with federal and/or private environmental funds, not state funds. The Platte Basin survey data were also used to study the impact of technical knowledge on Platte River policy preferences. It was found that technical beliefs rather
than values were the dominant factor that explains differences in policy preferences. This suggests that there is clearly an opportunity for education to contribute to conflict resolution.
Impacts
Results from this study are being used by Natural Resource Districts in Nebraska, as they revise their water quality management plans, and by the Governance Committee for the Platte Basin Cooperative Agreement, as they seek a bargained agreement on Platte River management. Results from the water quality study are likely to lead to more widespread use of programs to prevent nitrate contamination of groundwater, whereas historically most programs have focused exclusively on geographic areas that were already severely contaminated. The bargaining model results for the Platte Basin increase the likelihood that the states of Colorado, Nebraska and Wyoming, and the U. S. Department of Interior will eventually reach an agreement on how to manage Platte River resources to meet endangered species needs.
Publications
- Ahmad, Saeed. 2001. "A Dynamic Analysis of the Tradeoffs Between Nitrate Pollution of Groundwater and Economic Returns to Irrigated Agriculture", Unpublished Ph.D. dissertation, Department of Agricultural Economics, University of Nebraska-Lincoln.
- Ahmad, S. and R. J. Supalla. 2002. "A Dynamic Analysis of the Tradeoffs Between Nitrate Pollution of Groundwater and Economic Returns to Irrigated Agriculture", Poster Paper Abstract, American Journal of Agricultural Economics, Vol. 85, No. 5.
- Skonard, C. J. and D. L. Martin. 2002. A Physically Based Two-dimensional Infiltration Model for Furrow Irrigation. ASAE-CIGR Meeting Paper No. 022063, St. Joseph, MI.
- Supalla, R. J., B. Klaus, O. Yeboah and J. Allen. 2002. Game Theory as a Watershed Management Tool: A Case Study of the Middle Platte Ecosystem, Project Completion Report for Assistance Agreement R 82698701, National Center for Environmental Assessment, Cincinnati, Ohio.
- Supalla, R., B. Klaus, O. Yeboah and R. Bruins. 2002. "A Game Theory Approach to Deciding Who Will Supply Instream Flow Water", Journal of the American Water Resources Association, Volume 30, No. 4, pages 959-966.
- Supalla, R. J. and S. Ahmad. 2002. "The Dynamics of Water Quality", Focus, Department of Agricultural Economics, University of Nebraska-Lincoln, Spring/Summer Issue, pages 12-19.
- Supalla, R. J., B. Klaus, S. Ahmad and R. Bruins. 2002. "Solving Water Use Conflicts Using Game Theory Bargaining Models", Poster Paper Abstract, American Journal of Agricultural Economics, Vol. 85, No. 5.
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Progress 10/01/00 to 09/30/01
Outputs
Policy alternatives for resolving disputes over the allocation of water in the Middle Platte region were analyzed using bargaining models derived from game theory. The dispute involves disagreements in Colorado, Nebraska and Wyoming over how much water should be allocated to the protection of threatened and endangered species, who should supply it and who should pay for it. The water management preferences of households in all three states were determined by mail survey and incorporated in the bargaining models. The survey results indicated that the most important differences of opinion regarding Middle Platte management policies existed between agricultural and environmental interest groups within each state, rather than between states. At the aggregate level, all three states preferred a policy which called for an adaptive management approach that minimized the reallocation of water from agriculture to environmental uses and involved a modest level of investment,
with the costs shared equally between the federal government, the states and private environmental interests. Within each state, however, agricultural interests preferred to invest nothing, while environmental interests preferred a much more aggressive program to ensure endangered species protection. The dominant policy attribute for all interest groups was payment policy. Private environmental interests showed a surprising willingness to support private contributions to the cost of Middle Platte management programs and agricultural interests were much more willing to endorse a significant endangered species protection program if the state cost share was minimized and there was a substantial private contribution. Results from the application of three different sets of bargaining rules suggest that a negotiated solution is most likely to consist of an adaptive management approach that minimizes the reallocation of water and an equal sharing of the costs between federal, state and
private entities. The egalitarian bargaining solution, however, suggested that if the negotiating parties endorse strong equity objectives, then the most likely outcome is a somewhat more aggressive program of endangered species protection involving more water reallocation and higher investment costs. Another study has focused on the development of models to simulate the impact of management practices on ground water quality in the Platte River Valley. Dynamic programming was used to analyze least cost methods of meeting groundwater quality goals. It was found that reducing nitrogen applied, shifting from gravity to sprinkler irrigation and shifting from continuous corn to the production of as much alfalfa as practical would materially reduce nitrate concentrations in groundwater at a manageable economic cost. However, the results also suggest that it would take more than 50 years to get from current nitrate levels of about 30 mg/l to something below the maximum contaminant level of
10 mg/l even if economic considerations were ignored.
Impacts
The results of a game theory analysis of Platte River water allocation disputes are being used by policy persons involved in finding an acceptable water management plan. Prospects for dispute resolution were enhanced by the finding that if private environmental interests rather than taxpayers paid part of the cost of reallocating water from agriculture to endangered species, then agricultural interests would be more likely to support requests for endangered species water. They were also enhanced by the finding that much of the disagreement between agricultural and environmental interest groups would cease to exist if both groups had technical beliefs that were similar to those held by well informed individuals; hence, it may be possible to significantly reduce management disputes with technical education programs.
Publications
- Saeed, A. 2001. "A Dynamic Anlaysis of the Tradeoffs Beween Nitrate Pollution of Groundwater and Economic Returns to Irrigated Agriculture," unpublished Ph.D. Dissertation, University of Nebraska - Lincoln.
- Supalla, R.J.,Yeboah, O. Klaus, B., Allen, J. Allen and Bruins R. 2001 "Game Theory as a Watershed Management Tool," Proceedings of Symposium on Integrated Decision Making for Watershed Management Processes and Tools, Chevy Chase, Maryland, January, 2001.
- Supalla, R. J., Klaus, B. and Yeboah, O. 2001. "Using a Second Price Sequential Auction to Determine Who Will Supply and Who Will pay for Environmental Water", Proceedings of the 7th Conference of the International Water and Resource Economics Consortium and 4th Seminar on Environmental and Resource Economics, Girona, Spain, June, 2001.
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Progress 10/01/99 to 09/30/00
Outputs
Major progress was made this year on the development of game models for resolving disputes over the allocation of water in the Middle Platte region. The dispute involves disagreements over how much water should be allocated to the protection of threatened and endangered species, who should supply it, Colorado, Nebraska or Wyoming, and who should pay for it. A second price, sequential auction model for deciding who will supply endangered species water to the Middle Platte was developed and tested using simulated results. With this model the states bid sequentially to supply the water in 10,000 acre-foot blocks, with bids starting high and working down until no one was willing to reduce the bid price any further. The modeled results satisfied standard efficiency conditions, but suggest that a substantial premium above real supply costs will be required to induce the states with the least cost water to supply more than their proportional share. Other institutional
mechanisms for reallocating water from agriculture to endangered species were also evaluated. It was found that market allocations using multi-year leases would be a less costly source of endangered species water than the fee simple purchase of agricultural water rights.
Impacts
The state and federal officials who are negotiating who will supply and pay for endangered species water for the Middle Platte region have expressed interest in using the game model results. The water marketing results are expected to influence the content of water marketing legislation in Nebraska during year 2001.
Publications
- Supalla, Raymond J., "A Game Theoretic Critique of Institutional Arrangements for Platte River Management", International Journal of Water Resources, V18, No. 1, June 2000.
- Supalla, Raymond J., B. Klaus, J. Allen, O. Yeboah and R. Bruins, "Potential Contributions of Game Theory to Ecological Decision Making", Abstract in Ecosummit 2000: Integrating the Sciences, Elsevier Science Ltd., Oxford, UK., June 2000.
- Bruins, Randall F., J.R. Kahn, R.J. Supalla, O.H. Erekson, and O.L. Loucks, "A Framework for Integrating Ecological Risk Assessment and Economics in Watersheds", Abstract in Ecosummit 2000: Integrating the Sciences, Elsevier Science Ltd., Oxford, UK., June 2000.
- Supalla, Raymond J., O. Yeboah, B. Klaus and J. Allen, "Using a Sequential Auction to Determine Who Supplies and Who Pays for Water Reallocation", Poster Paper, Abstract published American Journal of Agricultural Economcs, V82, No. 5, December 2000.
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Progress 10/01/98 to 09/30/99
Outputs
The Root Zone Water Quality Model (RZWQM) was evaluated for conditions in Central Nebraska. The model was found to overstate storage of off-season precipitation, understate leaching, overstate yields and exaggerate N use efficiency. Alternatively, management practices for reducing nitrate pollution of groundwater were evaluated with respect to income and environmental effects using field research results and the EPIC model. To analyze if water leached from pivot irrigated fields contained less nitrate-nitrogen than water from furrow irrigated fields, changes in water quality between 1988 and 1997 were evaluated for pivot lands in the Central Platte NRD. Water quality was found to have improved slightly beneath the pivots, whereas there was no observed improvement beneath the furrow irrigated fields. However, because of field configuration and land ownership constraints only about 15 percent of the fields in the Central Platte NRD were suitable for center pivot
irrigation. Latin hypercube sampling was evaluated as a method of estimating furrow irrigation performance based on the distribution of soil texture across a field. The results suggest that Latin hypercube sampling can be used to significantly reduce the number of point simulations required to accurately simulate infiltration at a field level. An analysis of trends in the adoption of improved nitrogen management practices found that about 40 percent of all Nebraska corn producers had increased their use of deep soil tests and reduced nitrogen use during the past five years. Policy alternatives for inducing producers to adopt practices which reduce nitrate pollution of groundwater still further were analyzed using econometrics and linear programming models. Estimates of the elasticity of demand for nitrogen suggest that own price elasticity has fallen from greater than -1.0 to less than -0.2, as producers have become more environmentally concerned and education programs to improve
management have intensified. At an elasticity level of -0.2 it would cost over $1.00 per pound to reduce leaching at the current use level margin. In contrast, the voluntary adoption of BMP's was found to reduce nitrate leached at a cost of from less than zero (win-win situation) to about $0.50 per pound as one approaches the minimal leaching level for irrigated corn. These findings were confirmed by an LP analysis which found that education or regulations to induce the adoption of BMP's would be a more cost effective method of reducing nitrate pollution of groundwater than tax based incentive systems. The presence of win-win opportunities to simultaneously improve profitability and reduce groundwater pollution has important policy significance. It means that income reducing regulations, or input taxes, or government subsidies should not be necessary to induce reduced nitrate pollution of groundwater. The preferred policy option appears to be education, with perhaps some use of
regulations to induce those who are not responsive to education to change their production practices in ways that produce both economic and environmental improvements.
Impacts
Research has contributed to a 15 percent decline in Nitrogen use in the Central Platte region of Nebraska. For those situation where the amount of applied nitrogen exceeds plant requirements, each one percent decrease in the amount of nitrogen applied results in about a 25 cent increase in profits per acre of production and a 1.5 pound per acre decrease in the amount of nitrate leached to groundwater.
Publications
- Martin, D. L. and Watts, D.G. 1999. Evaluation of the Root Zone Water Quality Model for Conditions in Central Nebraska, Agronomy Journal, Vol. 91-2, pages 201-211.
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Progress 10/01/97 to 09/30/98
Outputs
Methods of augmenting stream flow through reduced groundwater irrigation were evaluated for tributaries to the Republican River in Nebraska. Reducing consumptive use by restricting irrigated acreage was found to be the least cost option at an average cost of $112 per acre foot for a 10 percent reduction. If stream flow was augmented by the same amount using the more common approach of regulating gross pumpage, however, costs averaged $196 per acre foot. Another study compared improved furrow irrigation strategies with sprinkler irrigation as methods of meeting economic and environmental objectives for potentially water short irrigated corn producers in Central Nebraska. Sprinkler irrigation was environmentally preferred in all cases and was economically preferred when irrigation labor was priced at about 150 percent of the minimum wage.
Impacts
(N/A)
Publications
- Osei-Agyman Yeboah. 1998. Economic Cost of Augmenting Stream flows in the Republican River in Southwest Nebraska, Unpublished Ph.D. Thesis, University of Nebraska-Lincoln.
- Hunter, W. V. III. 1998. Simulating Alternative Irrigation Systems and Strategies for Profitability Comparisons, Unpublished M.S. Thesis, University of Nebraska-Lincoln.
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Progress 10/01/96 to 09/30/97
Outputs
Two institutional dimensions of water quality management were addressed: producer adoption behavior and financial assistance rules for water quality programs in rural communities. Agricultural producers have been slow to adopt Best Management Practices (BMP's) for reducing nitrate pollution of groundwater, even though many BMP's which improve the environment also improve economic returns, or at worst cost very little to adopt. A statewide analysis of the nitrogen management practices of both dryland and irrigated producers found that education was the most important factor in explaining adoption rates. Technical understanding of both agricultural production processes and environmental linkages appeared to be the most critical educational dimension. Somewhat surprisingly, there was not an identifiable linkage between the location of field demonstration projects and the production practices of agricultural producers. The community financial assistance project addressed
the ability of 439 rural communities in Nebraska to pay for sewer and water services was evaluated. It was found that substantial subsidies are likely to be required in the future, but that both the cost and the effectiveness of existing federal and state financial assistance programs could be enhanced through rule changes to permit more widespread use of alternative technologies and more effective targeting of financial assistance.
Impacts
(N/A)
Publications
- Supalla, R.J., Ahmad, S. 1997. Defining the financial capacity of rural communities to meet sewer and water needs, Report NO. 175, Dept. of Agr. Econ., University of Nebraska-Lincoln.
- Juliano, B.D. 1997. Factors affecting nitrogen management practices of corn producers in nebraska, Unpublished M.S. Thesis, University of Nebraska - Lincoln.
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Progress 10/01/95 to 09/30/96
Outputs
The initial work on this project has focused on the institutional aspects of water management. Three sub-projects were initiated, one on water marketing, another on water quality criteria for rural water systems and a third on water system financing. Results are available only for the water system financing study. Preliminary findings indicate that allocating resources to communities based only on median household income, as is often done, is both inequitable and inefficient. Use of a multidimensional criterion involving both income distribution and wealth to identify the need for financial subsidies results in a very different community ranking that is more likely to result in public resources going to where they are most needed and most effective.
Impacts
(N/A)
Publications
- Supalla, R.J. 1996. Water marketing. Proceedings of Conf. on Nebraska WaterLaw, CLE Int., Denver, CO.
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