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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The impact of climate change on the effectiveness of water conservation policies in western Kansas and the Ogallala aquifer

Garay Armoa, Pedro Vicente January 1900 (has links)
Doctor of Philosophy / Department of Agricultural Economics / Jeffrey M. Peterson / Water scarcity is already a critical issue in many regions across the world and in many places water supplies are likely to be further threatened by climate change (Bates et al., 2008). Climate change will affect water availability in these areas both directly and indirectly. The direct effects come about because increased temperature (accompanied by changes in wind, humidity, and solar radiation) may increase evaporative losses from surface water bodies, and also because reduced precipitation lowers the rate of water inflows. In the case of groundwater, these factors will reduce the rate of aquifer recharge (Bates et al., 2008). The indirect effects arise from the biophysical impacts of climate change on vegetation, which are induced from rising temperatures, changing precipitation regimes, and increased atmospheric carbon dioxide levels. As a result of climate change, significant changes are expected in the hydrological cycle. This research is focused in how climate change can affect crop, land, and water allocation over time. The specific issue of this research comes from the following question: Is climate change likely to have a significant impact on the effectiveness of different water conservation policies in the High Plains aquifer region? This study is focused on the American High Plains, one of the most important water-scarce agricultural regions in North America. The study region for this research is a 31-county area overlying the Ogallala aquifer in western Kansas. This region encompasses approximately the western third of Kansas. Across these counties, the estimated remaining usable lifetime for aquifer water ranges from 50 to over 200 years (KGS), representing the range of water available in various parts of the aquifer. A Positive Mathematical Programming (PMP) model (Howitt, 1995) was developed and calibrated to land- and water-use data in the thirty one county area for a base period of 2000-2008. The PMP simulation uses inputs of price conditions and the aquifer level in a given year to predict the acreages planted to each of the major crops and the water use by crop. Decision makers are assumed to maximize profits, given the limited availability of water and arable land. The major crops in the model include wheat, corn, sorghum, soybeans, and alfalfa; the vast majority of historical planted acreage in the case counties is comprised of these five crops. The model was run for each of the case regions after calibrating the PMP model to data from 2000-2008. Calibration ensures that the model predictions fall within a small tolerance of the base period observations. This step avoids the problem of over-specialization (where the model places all of the acreages under one or two of the most profitable crops), and gives realistic acres and water use figures with which to work. The results suggest that the effects of the use of water conservation policies such as water use restriction and permanent conversion to dryland crops have positive effects on the trends of the different variables studied. With the implementation of these two policies, lower levels of total water use and higher levels of saturated thickness result but with a consequence of lower levels of net returns. However, the positive effects are lower in almost all cases if the effects of climate change on the same policies are taken into consideration. The scenarios of higher levels of temperature and lower precipitation levels projected for the region imply a greater demand for water for irrigated crops that results in lower levels of saturated thickness and simultaneously lower levels of net returns.
2

Understanding gully process in two Kansas landscapes

Burke, Katherine J. January 1900 (has links)
Doctor of Philosophy / Department of Environmental Design and Planning Program / Tim Keane / Gullies often form as a result of land use changes and associated factors such as soil compaction, vegetation removal and changes in rainwater infiltration. Gully erosion creates human safety hazards, soil loss, and sediment and nutrient pollution downstream. Across the globe, researchers have found a wide variety of gully growth rates and drivers (Poesen, Nachtergaele, Verstraeten, & Valentin, 2003), but after the late 1900s, very few published gully studies have been done in the United States, and fewer studies have been done in the Midwest and Great Plains regions. This gully study was conducted in two heavily-used Kansas landscapes: Fort Riley military training areas and agricultural fields in McPherson County. The purpose of the study was to quantitatively measure rates and patterns of gully erosion, as well as identify main drivers of gully initiation and growth. Results and conclusions add Kansas gully characteristics to the growing knowledge of gully erosion in other areas of the world. Gullies in both landscapes were surveyed in the field multiple times per year over three consecutive years (2012-2014) to capture patterns and rates of change. Rainfall data and land characteristics such as soils, vegetative cover, slope, and drainage area were compiled into a database to be compared to gully erosion rates in an attempt to correlate gully erosion not only to rainfall but to other land-based factors. Results show that for most Fort Riley gullies, beds are filling and banks are widening, and consistent drivers of erosion could not be determined from the data. In McPherson, gully channels are storing large amounts of sediment, though gully networks in the upper areas of the gully channels are actively widening and advancing headward. Drivers of channel change in McPherson County seem to be related to vegetative cover, slope, and early spring freeze/thaw processes. At both study locations, land use changes related to linear disturbance and reduced vegetative cover are suspected to have more of an influence on gully growth than rainfall events during the study timeframe. Objectives for best management practices are proposed for both Fort Riley and McPherson County.
3

Clustering Louisiana commercial fishery participants for the allocation of government disaster payment: the case of hurricanes Katrina and Rita

Ogunyinka, Ebenezer Oluwayomi January 1900 (has links)
Master of Science / Department of Statistics / John E. Boyer Jr / The purpose of this study is to evaluate the effectiveness of the methods used for allocating disaster funds to assist commercial fishery participants as a result of Hurricanes Katrina and Rita of 2005 and to examine alternative methods to aid in determining an efficient criterion for allocating public funds for fisheries assistance. The trip ticket data managed by the Louisiana Department of Wildlife and Fisheries were used and analyzed using a cluster analysis. Results from the clustering procedures show that commercial fishermen consist of seven clusters, while wholesale/retail seafood dealers consist of six clusters. The three tiers into which commercial fishermen were originally classified can be extended to at least eleven (11) clusters, made up of three (3) clusters in tier 1 and an equal number of clusters (4) clusters in tier 2 and tier 3. Similarly, the original three tiers of wholesale/retail seafood dealers can be reclassified into at least nine (9) clusters with two clusters in tier 1, four (4) clusters in tier 2 and three (3) clusters in tier 3. As a result of the clustering reclassifications, alternative compensation plans were developed for the commercial fishermen and wholesale/retail seafood dealers. These alternative compensation plans suggest a reallocation of disaster assistance funds among individual groups of fishermen and among individual groups of dealers. We finally recommend that alternative classification methods should always be considered in order to select the most efficient criterion for allocating public funds in the future.
4

Modeling eutrophication vulnerability in coastal Louisiana wetlands impacted by freshwater diversion: a remote sensing approach

Brien, Lynn Ferrara January 1900 (has links)
Doctor of Philosophy / Department of Geography / Kevin P. Price / A major strategy in response to rapid degradation and loss of Louisiana’s coastal wetlands has been the construction of siphon diversion projects. The diversions are designed to reintroduce nutrient enriched freshwater from the Mississippi River into wetland ecosystems to combat saltwater intrusion and stimulate marsh growth. The lack of consensus regarding the effects of river diversions on nutrient enrichment of wetland ecosystems is coupled with major concerns about eutrophication. Locating, assessing, and monitoring eutrophic marsh vegetation represent major challenges to understanding the impacts of freshwater diversions. As a result, this study was undertaken to investigate the feasibility of modeling eutrophication vulnerability of a coastal Louisiana marsh receiving turbid Mississippi River water. The major objective was to integrate remotely sensed data with field measurements of vegetation biophysical characteristics and historical ecosystem survey data to delineate landscape patterns suggestive of vulnerability to eutrophication. The initial step in accomplishing this goal was to model the spatial distribution of freshwater impacts using satellite image-based turbidity frequency data associated with siphon diversion operation. Secondly, satellite and spectroradiometer band combinations and vegetation indices optimal for modeling marsh biophysical characteristics related to nutrient enrichment were identified. Finally, satellite image data were successfully integrated with measures of historical and concurrent marsh biophysical characteristics to model the spatial distribution of eutrophication vulnerability and to elucidate the impacts of freshwater diversions.
5

Quantifying patterns and select correlates of the spatially and temporally explicit distribution of a fish predator (Blue Catfish, Ictalurus furcatus) throughout a large reservoir ecosystem

Peterson, Zachary James January 1900 (has links)
Master of Science / Division of Biology / Martha E. Mather / Understanding how and why fish distribution is related to specific habitat characteristics underlies many ecological patterns and is crucial for effective research and management. Blue Catfish, Ictalurus furcatus, are an important concern for many fisheries agencies; however, lack of information about their distribution and habitat use remains a hindrance to proper management. Here, over all time periods and across months, I quantified Blue Catfish distribution and environmental correlates of distribution in Milford Reservoir, the largest reservoir in Kansas. I tested relationships among acoustically tagged Blue Catfish and three groups of variables postulated to influence Blue Catfish distribution in the literature (i. localized microhabitat variables, ii. larger-scale mesohabitat variables, iii. biotic variables). Blue Catfish were consistently aggregated in two locations of the reservoir across five months during summer and fall, 2013. Using multiple linear regression and an information theoretic model selection approach, consistent correlates of distribution included localized, microhabitat variables (i.e., dissolved oxygen, slope) larger-scale, mesohabitat variables (i.e., distance to channel, river kilometer from the dam) and a biotic variable (i.e., Secchi depth). This research identified which 5 of the 12 variables identified in the literature were most influential in determining Blue Catfish distribution. As a guide for future hypothesis generation and research, I propose that Blue Catfish distribution was driven by three ecologically-relevant tiers of influence. First, Blue Catfish avoided extremely low dissolved oxygen concentrations that cause physiological stress. Second, Blue Catfish aggregated near the channel, an area of bathymetric heterogeneity that may offer a foraging advantage. Third, Blue Catfish aggregated near low Secchi depths, shown here to be associated with increased productivity and prey abundance. Building on my results, future research into the distribution and habitat use of Blue Catfish should incorporate aggregated distributions of fish into research designs, focus on how both small and large scale relationships interact to produce patterns of distribution, and explore further the mechanisms, consequences, and interactions among the three tiers of influence identified here.
6

Hydraulic fracturing and shale gas extraction

Klein, Michael January 1900 (has links)
Master of Science / Department of Chemical Engineering / James Edgar / In the past decade the technique of horizontal drilling and hydraulic fracturing has been improved so much that it has become a cost effective method to extract natural gas from shale formations deep below the earth’s surface. Natural gas extraction has boomed in the past few years in the United States, enough that it has driven prices to an all time low. The amount of natural gas reserves in the U.S. has led to claims that it can lead the country to energy independence. It has also been touted as a cleaner fuel for electricity generation and to power vehicles. This report explains hydraulic fracturing and horizontal drilling particularly with regards to utilizing the techniques for natural gas extraction from shale gas. It also discusses the environmental impact due to the drilling and gas extraction. It demonstrates that although the natural gas beneath the U.S. is a valuable resource, the impacts to the planet and mankind are not to be taken lightly. There is the potential for the effects to be long term and detrimental if measures are not taken now to control them. In addition although on the surface natural gas seems to be a greener fuel, particularly in comparison to gasoline, it is also considered worse for the environment.
7

Condit dam removal : a decision-making comparison with removal of Elwha River dams

Wallace, Laura January 1900 (has links)
Master of Arts / Department of Geography / Lisa M.B. Harrington / While environmental concerns have played a secondary role in dam removal rationales thus far, the Condit and Elwha removal projects could signal a change in governmental and public priorities in dam management in the United States (Born et al. 1998; Bednarek 2002). For this research, I compared two dam removal projects designed to restore native salmon runs in two rivers in Washington State: the Condit Dam on the White Salmon River and the Elwha and Glines Canyon Dams on the Elwha River. This thesis asks: given choices of preserving dams that produce clean electricity and the well-established lake-based habitats created by their reservoirs or re-establishing a free-flowing river to reestablish fish and wildlife populations, how are decisions made, and what does the process and outcome mean to local communities? Research interview data was used in combination with policy documents to answer three research questions: 1) What factors affect decision-makers’ and other stakeholders’ support for (or rejection of) dam removal? 2) How did stakeholders’ perceptions and opinions play a role in the decision-making process? and 3) What can we learn from problems and successes evident from the dam removal decision processes? The main factors influencing both the Condit Project and the Elwha Project were environmental (salmon restoration), political (meeting legislative requirements for fish passage), and economic (finding the least cost fish passage alternative). The primary motivation for both projects was salmon restoration via the provision of federally mandated fish passage. The possibility of regaining a valuable resource spurred Tribal, federal, and state agencies to advocate for the removal alternative. Dam owners in both cases desired the least cost option, resulting either in their consent to removal (Condit Project) or selling the dams and relinquishing responsibility to the federal government (Elwha Project). Both took over two decades to complete and were removed in 2011. Perceptions of the relative importance of removal/retention options and dissatisfaction with the decision-making process led to polarization of the communities affected by the dam removals and contributed to the 20+ year project timelines. In order to promote good will and understanding between decision makers and stakeholders, two lessons can be learned from the Condit and Elwha Projects: 1) actively seek to include both proponents and opponents in decision-making and 2) establish robust communication among stakeholders and decision makers. Additionally, preliminary evidence indicates that dam removal does result in movement of salmonids to river reaches that had been blocked by dams, and dam removal may also lead to unintended consequences related to local environmental quality and resource access, such as short term air quality concerns and longer term effects on groundwater availability.
8

An analysis of alternative soil, nutrient, and water management strategies.

Smith, Craig Matthew January 1900 (has links)
Doctor of Philosophy / Department of Agricultural Economics / Jeffery R. Williams / The two topics addressed in this dissertation are both related to surface water quality. Reservoir sedimentation and water quality trading are examined from economic and environmental perspectives. Each topic and the resulting policy implications are relevant to stakeholders at the local, state, and federal levels. Reservoir sedimentation has been recognized as a major environmental, social, and economic issue in much of the Midwestern US. There is an effort to focus public and private funds to achieve the greatest return on the investment from soil erosion and sediment reduction strategies. How can physiographical and economic relationships within the watershed be quantified in such a way to provide insights into the selection of alternative management strategies? This study focuses on answering that question by integrating a physically-based watershed model with an economic analysis of alternative sedimentation reduction strategies for the case of Tuttle Creek Lake located in northeastern Kansas. Several key finding of this study are that both physiographical and economic factors must be considered for cost-effective conservation to occur. Considering these factors and targeting BMP implementation from 8 to 23 times more cost-effective than random implementation. If targeting cannot be done effectively or if “intangible” costs of BMP implementation are too large, dredging is likely to be more cost-effective. While this research compares the cost-effectiveness of various BMP implementation approaches in Kansas with dredging, the benefits associated with each of these strategies is not addressed. While there is substantial evidence that nonpoint sources have lower nutrient reduction costs than point sources, experience with water quality trading (WQT) reveals a common theme: little or no trading activity. These outcomes suggest the presence of obstacles to trading that were not recognized in the design of existing programs. To examine the ways that various market imperfections may impact the performance of a WQT market, an agent-based model is constructed, which simulates a hypothetical point-nonpoint market. This study first presents an overview of the concepts and simulation modeling technique used and then analyzes the effects of two prominent market impediments identified in the WQT literature: information levels and trading ratios. The results imply that if market designers feel that only a limited number of trades will be consummated, creating an institution that provides accessible information about buyers’ prices is preferred to providing information about sellers’ prices. Overall, more information is always better, but it becomes less important with higher trading ratios.
9

Ex-ante economic and ecosystem service potential of simulated conservation practices in Ghana using a minimum data approach

Remaury, Hugo January 1900 (has links)
Master of Science / Department of Agricultural Economics / Timothy J. Dalton / Given the changing climate paradigm, food and poverty are likely to become more severe in Africa. Farmers can adapt to climate change, especially through conservation agriculture. This study relies on a minimum data approach developed by Antle and Valvidia (2006) to estimate the spatial distribution of opportunity cost for farmers in switching to conservation practices in Wa, Ghana. It assesses the economic feasibility of several scenarios that rely on production techniques currently studied by the CRSP SANREM project. We also explore the possibility that these practices can provide income from carbon sequestration payments implemented by the Kyoto protocol’s Clean Development Mechanisms. The methodology uses data from both a recent survey and information from secondary sources to assess simulated management practices. Results indicate that all the simulated management practices would theoretically benefit farmers. In fact, adoption rates for the four scenarios range from 52% to 65%, even without any carbon payment. Adding a proportional payment to the amount of carbon sequestered with these practices does not seem enough to influence farmers switch to switch to alternative scenarios. The analysis shows that these results hold even when additional fixed costs to adopt these practices are included. This case study demonstrates the usefulness of the minimum data approach in estimating the economic potential of conservation practices in Ghana. These production techniques may represent environmentally-friendly alternatives that are more profitable for farmers than current practices. The next step in assessing implementation of such practices would require studying farmers’ willingness to adopt these production systems, given their ex-ante economic returns.
10

Effectiveness of interpretive exhibits at Brown v. Board of Education National Historic Site

Stork, Lisa January 1900 (has links)
Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Ted Cable / National parks reach out to millions of people each year by offering a number of recreational and educational experiences. People are exposed to new ideas and experiences in a national park that they may not get anywhere else. At Brown v. Board of Education National Historic Site in Topeka, Kansas, the National Park Service (NPS) compels visitors to step into the shoes of African American students in a segregated elementary school through the use of interpretive exhibits. This study was conducted to evaluate the effectiveness of the interpretive exhibits at Brown v. Board of Education National Historic Site. Most visitors sampled (91%) were visiting for the first time, indicating that the site does not have many repeat visitors. Race and the American Creed, the 30 minute film that plays in the auditorium, was found the most impactful exhibit by 34.3% of visitors surveyed. Expressions and Reflections, the temporary exhibit in the Kindergarten room, was the second most impactful exhibit, at 21.6% of visitors surveyed. The least impactful exhibit was the film Pass It On, at 0.9% of visitors surveyed. As a whole, visitors were most impacted by dynamic exhibits with a clear theme, while static exhibits and those that did not have a clear theme were not as impactful. This research will help guide Brown v. Board of Education National Historic Site staff as they contemplate future changes in the interpretive exhibits.

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