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| Registros recuperados: 29 | |
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| Feng, Hongli; Jha, Manoj K.; Gassman, Philip W.. |
| A watershed based model, the Soil and Water Assessment Tool (SWAT), along with transfer coefficients is used to assess alternative principles of allocating nutrient load reduction in the Raccoon River watershed in central Iowa. Four principles are examined for their cost-effectiveness and impacts on water quality: absolute equity, equity based on ability, critical area targeting, and geographic proximity. Based on SWAT simulation results, transfer coefficients are calculated for the effects of nitrogen application reduction. We find both critical area targeting and downstream focus (an example of geographic proximity) can be more expensive than equal allocation, a manifestation of absolute equity. Unless abatement costs are quite heterogeneous across the... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Environmental Economics and Policy. |
| Ano: 2006 |
URL: http://purl.umn.edu/21131 |
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| Secchi, Silvia; Jha, Manoj K.; Kurkalova, Lyubov A.; Feng, Hongli; Gassman, Philip W.; Kling, Catherine L.. |
| This study investigates the implications of treating different environmental benefits as the primary target of policy design. We focus on two scenarios, estimating for both of them in-stream sediment, nutrient loadings, and carbon sequestration. In the first, we assess the impact of a program designed to improve water quality in Iowa on carbon sequestration, and in the second, we calculate the water quality impact of a program aimed at maximizing carbon sequestration. In both cases, the policy instrument is the retirement of land from agricultural production. Our results, limited to the state of Iowa, and to the case of set-aside for water quality or carbon sequestration purposes, indicate that the amount of co-benefits depends on what indicators are used... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Carbon sequestration; Co-benefits; Environmental benefits targeting; Iowa; Land set-aside; Water quality; Environmental Economics and Policy. |
| Ano: 2005 |
URL: http://purl.umn.edu/18353 |
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| Gassman, Philip W.. |
| This paper presents the underlying assumptions and results for the Agricultural Policy/Environmental eXtender (APEX) model, which was applied within an integrated modeling system for the National Policy Program (NPP) environmental baseline simulations for the Upper North Bosque River Watershed (UNBRW), located in Earth County, Texas. The integrated modeling system consists of an economic model that is linked to an environmental component comprising the field-scale APEX and watershed-scale Soil Water Assessment Tool (SWAT) models. The environmental baseline simulations test and calibrate the complete environmental component, using monitoring data obtained during 1993-94 in the UNBRW. The economic model was not executed for the environmental baseline,... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Environmental Economics and Policy. |
| Ano: 1997 |
URL: http://purl.umn.edu/18668 |
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| Kanwar, Ramesh S.; Reungsang, Pipat; Jha, Manoj K.; Gassman, Philip W.; Ahmad, Khalil; Saleh, Ali. |
| A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling approach, edge-of-field flows and pollutant load estimates were generated for manure application fields with APEX and were then subsequently routed to the watershed outlet in SWAT, along with flows and pollutant loadings estimated for the rest of the watershed routed to the watershed outlet. In the current study, the entire UMRW cropland area was simulated in SWAT, which... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Calibration; Modeling; Nitrate; SWAT; Validation; Water quality; Resource /Energy Economics and Policy. |
| Ano: 2005 |
URL: http://purl.umn.edu/18440 |
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| Gassman, Philip W.; Hauck, Larry M.. |
| This paper briefly describes the environmental component of an integrated modeling system that has been developed for simulating the movement of nutrients (nitrogen and phosphorus) from dairy waste disposal fields through the Upper North Bosque River Watershed (UNBRW) stream network in Erath and Hamilton Countries, Texas, as part of the "Livestock and the Environment: A National Pilot Project" (NPP). The environmental component consists of the Agricultural Policy/Environmental eXtender (APEX) model and the Soil Water Assessment Tool (SWAT). The APEX model is designed to simulate the edge-of-field nutrient runoff and leaching loadings from the application of solid and liquid manure on dairy waste disposal fields that are subsequently routed through the... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Environmental Economics and Policy. |
| Ano: 1996 |
URL: http://purl.umn.edu/18663 |
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| Gassman, Philip W.; Williams, Jimmy R.; Wang, Xiuying; Saleh, Ali; Osei, Edward; Hauck, Larry M.; Izaurralde, R. Cesar; Flowers, Joan D.. |
| The Agricultural Policy Environmental eXtender (APEX) model was developed by the Blacklands Research and Extension Center in Temple, Texas. APEX is a flexible and dynamic tool that is capable of simulating a wide array of management practices, cropping systems, and other land use across a broad range of agricultural landscapes, including whole farms and small watersheds. The model can be configured for novel land management strategies, such as filter strip impacts on pollutant losses from upslope cropfields, intensive rotational grazing scenarios depicting movement of cows between paddocks, vegetated grassed waterways in combination with filter strip impacts, and land application of manure removal from livestock feedlots or waste storage ponds. A... |
| Tipo: Report |
Palavras-chave: APEX; Best management practices; Farm and watershed simulations; Soil carbon; Water quality; Environmental Economics and Policy. |
| Ano: 2009 |
URL: http://purl.umn.edu/49156 |
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| Feng, Hongli; Kling, Catherine L.; Gassman, Philip W.. |
| Land use changes to sequester carbon also provide "co-benefits," some of which (for example, water quality) have attracted at least as much attention as carbon storage. The non-separability of these co-benefits presents a challenge for policy design. If carbon markets are employed, then social efficiency will depend on how we take into account co-benefits, that is, externalities, in such markets. If carbon sequestration is incorporated into conservation programs, then the weight given to carbon sequestration relative to its co-benefits will partly shape these programs. Using the Conservation Reserve Program (CRP) as an example, we show that CRP has been sequestering carbon, which was not an intended objective of the program. We also demonstrate that more... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Carbon sequestration; Co-benefits; Conservation Reserve Program; Environmental Economics and Policy. |
| Ano: 2004 |
URL: http://purl.umn.edu/18336 |
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| Feng, Hongli; Kurkalova, Lyubov A.; Kling, Catherine L.; Gassman, Philip W.. |
| This study investigates the carbon sequestration potential and co-benefits from policies aimed at retiring agricultural land in the Upper Mississippi River Basin, a large, heavily agricultural area. We extend the empirical measurement of co-benefits from the previous focus on environmental benefits to include economic transfers. These transfers have often been mentioned as a co-benefit, but little empirical work measuring the potential magnitude of these transfers has previously been undertaken. We compare and contrast five targeting schemes, each based on maximizing different physical environmental measures, including carbon sequestration, soil erosion, nitrogen runoff, nitrogen leaching, as well as the area enrolled in the program. In each case, the... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Carbon sequestration; Co-benefits; Co-effects; Economic transfers; Environmental benefits targeting; Upper Mississippi River Basin; Environmental Economics and Policy; Land Economics/Use. |
| Ano: 2005 |
URL: http://purl.umn.edu/18423 |
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| Jha, Manoj K.; Arnold, Jeffrey G.; Gassman, Philip W.. |
| The Raccoon River Watershed (RRW) in West-Central Iowa has been recognized as exporting some of the highest nitrate-nitrogen loadings in the United States and is a major source of sediment and other nutrient loadings. An integrated modeling framework has been constructed for the RRW that consists of the Soil and Water Assessment Tool (SWAT) model, the interactive SWAT (i_SWAT) software package, Load Estimator (LOADEST) computer program, and other supporting software and databases. The simulation framework includes detailed land use and management data such as different crop rotations and an array of nutrient and tillage management schemes, derived from the U.S. Department of Agriculture's National Resources Inventory databases and other sources. This paper... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Calibration; Management practices; Raccoon River Watershed; SWAT; Resource /Energy Economics and Policy. |
| Ano: 2006 |
URL: http://purl.umn.edu/18455 |
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| Secchi, Silvia; Gassman, Philip W.; Jha, Manoj K.; Kurkalova, Lyubov A.; Kling, Catherine L.. |
| While biofuels may yield renewable fuel benefits, there could be downsides in terms of water quality and other environmental stressors, particularly if corn is relied upon exclusively as the feedstock. In this article, we describe a modeling system that links agricultural land use decisions in the Upper Mississippi River Basin (UMRB) to economic drivers. This modeling system is then used to assess several scenarios to identify the water quality effects of alternative land uses and the impacts of introducing on the landscape alternative feedstocks, such as switchgrass, to support renewable energy goals. Specifically, a scenario that assesses the water quality effects associated with an increase in corn acreage due to higher relative corn prices provides an... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Crop Production/Industries; Environmental Economics and Policy; Resource /Energy Economics and Policy. |
| Ano: 2008 |
URL: http://purl.umn.edu/53498 |
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| Registros recuperados: 29 | |
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