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| Registros recuperados: 14 | |
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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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| 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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| 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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| Jha, Manoj K.. |
| This paper describes the application of the Soil and Water Assessment Tool (SWAT) model to the Maquoketa River watershed, located in northeast Iowa. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science Integrating Point and Nonpoint Sources (BASINS). Climatic data from six weather stations located in and around the watershed, and measured streamflow data from a U.S. Geological Survey gage station at the watershed outlet were used in the sensitivity analysis of SWAT model parameters as well as its calibration and validation for watershed hydrology and streamflow. A sensitivity analysis was performed using an influence coefficient method to evaluate surface... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Calibration and validation; Hydrologic simulation; Sensitivity analysis; SWAT.; Environmental Economics and Policy. |
| Ano: 2009 |
URL: http://purl.umn.edu/51123 |
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| Registros recuperados: 14 | |
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