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In this paper, we present an economic analysis of CO2-enhanced oil recovery (EOR). This technique entails injection of CO2 into mature oil fields in a manner that reduces the oil's viscosity, thereby enhancing the rate of extraction. As part of this process, significant quantities of CO2 remain sequestered in the reservoir. If CO2 emissions are regulated, oil producers using EOR should therefore be able to earn revenues from sequestration as well as from oil production. We develop a theoretical framework that analyzes the dynamic co-optimization of oil extraction and CO2 sequestration, through the producer's choice of the fraction of CO2 in the injection stream at each moment. We find that the optimal fraction of...
In this paper, we present an economic analysis of CO2-enhanced oil recovery (EOR). This technique entails injection of CO2 into mature oil fields in a manner that reduces the oil's viscosity, thereby enhancing the rate of extraction. As part of this process, significant quantities of CO2 remain sequestered in the reservoir. If CO2 emissions are regulated, oil producers using EOR should therefore be able to earn revenues from sequestration as well as from oil production. We develop a theoretical framework that analyzes the dynamic co-optimization of oil extraction and CO2 sequestration, through the producer's choice of the fraction of CO2 in the injection stream at each moment. We find that the optimal fraction of...
Using a model as a management tool requires testing of the model against field-measured data prior to its application for solving natural resource problems. This study was conducted to test the Root Zone Water Quality Model (RZWQM98) using four years (1996 to 1999) of field-measured data to simulate the effects of different N-application rates on corn yields and nitrate-nitrogen (NO[3]-N) losses via subsurface drain water. Three N-application rates (low, medium, and high), each replicated three times, were applied to corn in 1996 and 1998 under a randomized complete block design at a tile-drained corn-soybean rotation field near Story City, Iowa. No N-fertilizer was applied to soybean in 1997 and 1999. Model calibration...
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Synopsis: This article outlines how wetlands can significantly reduce flooding in the Upper Mississippi watershed. The authors first provide a historical context by estimating the original and lost wetland storage capacities of the Upper Mississippi and Missouri River Basins. Historically, about 10% of the basin would have been classified as wetland in 1780. By 1980, wetland acreage had been reduced to only 4% of the basin, representing about 26 million acres of wetlands eliminated since 1780. The area of wetland restoration required to reduce the risk of future flooding adequately was estimated based on the total amount of excess floodwater beyond bank-full discharge that passed through the City of St. Louis during...
In this paper, we present an economic analysis of CO2-enhanced oil recovery (EOR). This technique entails injection of CO2 into mature oil fields in a manner that reduces the oil's viscosity, thereby enhancing the rate of extraction. As part of this process, significant quantities of CO2 remain sequestered in the reservoir. If CO2 emissions are regulated, oil producers using EOR should therefore be able to earn revenues from sequestration as well as from oil production. We develop a theoretical framework that analyzes the dynamic co-optimization of oil extraction and CO2 sequestration, through the producer's choice of the fraction of CO2 in the injection stream at each moment. We find that the optimal fraction of...
In this paper, we present an economic analysis of CO2-enhanced oil recovery (EOR). This technique entails injection of CO2 into mature oil fields in a manner that reduces the oil's viscosity, thereby enhancing the rate of extraction. As part of this process, significant quantities of CO2 remain sequestered in the reservoir. If CO2 emissions are regulated, oil producers using EOR should therefore be able to earn revenues from sequestration as well as from oil production. We develop a theoretical framework that analyzes the dynamic co-optimization of oil extraction and CO2 sequestration, through the producer's choice of the fraction of CO2 in the injection stream at each moment. We find that the optimal fraction of...
Conclusions:Wetlands and riparian zones should be strategically placed in watersheds to optimize nitrogen removal, as, for example, in tile-drained farmlands prone to high concentrations of nitrateThresholds/Learnings:Restoring 10 million hectares of riparian zones and wetlands, representing 3.4% of the Mississippi River basin, would reduce nitrogen in the Mississippi River Basin and its tributaries by an average of 40%
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Separate data for floodplain elevation and bathymetry were collected on the Upper Mississippi River System (UMRS) by the US Army Corps of Engineers (USACE), Upper Mississippi River Restoration (UMRR) program. While many information needs can be met by using these data separately, in many cases seamless elevation data across the river and its floodplain are needed. This seamless elevation surface was generated by merging lidar (i.e., floodplain elevation) and bathymetry data. Merging the data required special processing in the areas of transition between the two sources of data.
Opportunities to improve the ecological functioning of agricultural landscapes in the U.S. Midwest exist, and could include the restoration of native plant communities to improve biodiversity or the modification of agricultural production systems to enhance the provisioning of ecosystem services to society. To be most effective in achieving these goals, restoration efforts require knowledge of past conditions and drivers of change. We assessed landscape change in the Clear Creek, Iowa watershed from 1940 to 2002 using five metrics derived from aerial photos: land cover composition and configuration, housing density and spatial pattern, and stream sinuosity. Major cover changes in the watershed included increases...
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Conclusions: Nest predators with different home-range sizes and habitat affinities responded to landscape configuration in different ways. Influence of landscape structure varied across scale. Thresholds/Learnings: Herbaceous cover was negatively associated with predation in roadsides whereas the proximity of woody cover was positively associated with predation rates. Synopsis: This study evaluated the influence of habitat structure and spatial configuration on nest predation in central Iowa. In a multi-scale analysis of 10 artificial ground nests along 136 roadsides across six watersheds, researchers found that predation was affected by the surrounding landscape mosaic. Nest predators with different home-range...
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Conclusions: Emigration rates are closely tied to edge structure. Low contrast edges promote edge permeability Thresholds/Learnings: Synopsis: The behavior of two butterfly species, one habitat specialist and one habitat generalist, were tracked at four prairie edges to determine the extent to which edge structure affects emigration. The specialist species responded strongly to all edges, and was particularly affected by edge density. The generalist species responded strongly only to high contrast edges. Emigration rates are closely tied to edge structure. Therefore, promoting low contrast edges in conservation planning may positively influence edge permeability and species richness in highly fragmented landscapes.
The productivity of grasslands depends in part on their diversity of species and functional composition. Our objective was to examine the effects of three landscape positions (summit, backslope, and toeslope) and three stocking systems (continuous, rotational, and nongrazed) on species diversity and percentage of cover of grass, legume, and weed species functional types in southeastern Iowa pastures. Data were collected in 0.2-m2 plots randomly distributed throughout each of four replicate pastures in spring and summer 2000 and 2001. Backslope landscape positions within pastures managed with either continuous or rotational stocking contained the greatest overall diversity of species. Across years, overall species...
In this paper, we present an economic analysis of CO2-enhanced oil recovery (EOR). This technique entails injection of CO2 into mature oil fields in a manner that reduces the oil's viscosity, thereby enhancing the rate of extraction. As part of this process, significant quantities of CO2 remain sequestered in the reservoir. If CO2 emissions are regulated, oil producers using EOR should therefore be able to earn revenues from sequestration as well as from oil production. We develop a theoretical framework that analyzes the dynamic co-optimization of oil extraction and CO2 sequestration, through the producer's choice of the fraction of CO2 in the injection stream at each moment. We find that the optimal fraction of...
In this paper, we present an economic analysis of CO2-enhanced oil recovery (EOR). This technique entails injection of CO2 into mature oil fields in a manner that reduces the oil's viscosity, thereby enhancing the rate of extraction. As part of this process, significant quantities of CO2 remain sequestered in the reservoir. If CO2 emissions are regulated, oil producers using EOR should therefore be able to earn revenues from sequestration as well as from oil production. We develop a theoretical framework that analyzes the dynamic co-optimization of oil extraction and CO2 sequestration, through the producer's choice of the fraction of CO2 in the injection stream at each moment. We find that the optimal fraction of...
In this paper, we present an economic analysis of CO2-enhanced oil recovery (EOR). This technique entails injection of CO2 into mature oil fields in a manner that reduces the oil's viscosity, thereby enhancing the rate of extraction. As part of this process, significant quantities of CO2 remain sequestered in the reservoir. If CO2 emissions are regulated, oil producers using EOR should therefore be able to earn revenues from sequestration as well as from oil production. We develop a theoretical framework that analyzes the dynamic co-optimization of oil extraction and CO2 sequestration, through the producer's choice of the fraction of CO2 in the injection stream at each moment. We find that the optimal fraction of...
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Separate data for floodplain elevation and bathymetry were collected on the Upper Mississippi River System (UMRS) by the US Army Corps of Engineers (USACE), Upper Mississippi River Restoration (UMRR) program. While many information needs can be met by using these data separately, in many cases seamless elevation data across the river and its floodplain are needed. This seamless elevation surface was generated by merging lidar (i.e., floodplain elevation) and bathymetry data. Merging the data required special processing in the areas of transition between the two sources of data.
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Synopsis: Agronomic intensification has transformed many agricultural landscapes into expansive monocultures with little natural habitat. A pervasive concern is that such landscape simplification results in an increase in insect pest pressure, and thus an increased need for insecticides. We tested this hypothesis across a range of cropping systems in the Midwestern United States, using remotely sensed land cover data, data from a national census of farm management practices, and data from a regional crop pest monitoring network. We found that, independent of several other factors, the proportion of harvested cropland treated with insecticides increased with the proportion and patch size of cropland and decreased...
    map background search result map search result map Butterfly responses to habitat edges in highly fragmented prairies of central Iowa. Flood reduction through wetand restoration: the Upper Mississippi River Basin as a case history. Effects of landscape structure on nest predation on roadsides of a mid-western agroecosystem: a multi-scale analysis. Agricultural landscape simplification and insecticide use in the Midwestern United States. UMRR Pool 09 Topobathy UMRR Pool 13 Topobathy UMRR Pool 09 Topobathy UMRR Pool 13 Topobathy Butterfly responses to habitat edges in highly fragmented prairies of central Iowa. Effects of landscape structure on nest predation on roadsides of a mid-western agroecosystem: a multi-scale analysis. Flood reduction through wetand restoration: the Upper Mississippi River Basin as a case history. Agricultural landscape simplification and insecticide use in the Midwestern United States.