Browsing by Author "Goemans, Christopher, committee member"
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Item Embargo A data-driven characterization of municipal water uses in the contiguous United States of America(Colorado State University. Libraries, 2024) Chinnasamy, Cibi Vishnu, author; Arabi, Mazdak, advisor; Sharvelle, Sybil, committee member; Warziniack, Travis, committee member; Goemans, Christopher, committee memberMunicipal water systems in the United States (U.S.) are facing increasing challenges due to changing urban population dynamics and socio-economic conditions as well as from the impacts of weather extremities on water availability and quality. These challenges pose a serious risk to the municipal water providers by hindering their ability to continue providing safe drinking water to residents while also securing adequate supply for economic growth. A data-driven approach has been developed in this study to characterize the trends, patterns, and urban scaling relationships in municipal water consumption across the Contiguous United States. Then using sophisticated and robust statistical methods, water consumption patterns are modeled, identifying key climatic, socio-economic, and regional factors. The first chapter of this data-driven study looked at municipal water uses of 126 cities and towns across the U.S. from 2005 to 2017, analyzing the temporal trends and spatial patterns in water consumption and identifying the influencing factors. Water usage in gallons per person per day, ratio of commercial, industrial, and institutional (CII) to Residential water use, and percent outdoor water consumption were statistically calculated using aggregated monthly and annual water use data. The end goal was to statistically relate the variations in CII to Residential water use ratio across the municipalities with their local climatic, socio-economic, and regional factors. The results indicate an overall decreasing trend in municipal water use, 2.6 gallons per person annually, with greater reductions achieved in the residential sector. Both Residential and CII water use exhibit significant seasonality over an average year. Large cities, particularly in the southern and western parts of the U.S. with arid climates, had the highest demand for water but also showed the largest annual reductions in their per capita water consumption. This study also revealed that outdoor water use varied significantly from 3 to 64 percent of the Total water consumption across the U.S., and it was highest in smaller cities in the western and arid regions. Factors such as April precipitation, annual vapor pressure deficit, number of employees in the manufacturing sector, total percentage of houses built before 1950, and total percentage of single-family houses explain much of the variation in CII to Residential water use ratio across the CONUS. The second chapter leverages high-resolution, smart-metered water use data from over 900 single-family households in Arizona for the water year 2021. This part of the study characterizes the determinants or drivers of water consumption patterns, specifically in single-family households, and presents a framework of statistical methods for analyzing smart-metered water consumption data in future research. A novel approach was developed to characterize household appliance efficiency levels using clustering techniques on 5-second interval data. Integrating water consumption data with detailed spatial information of the household and building characteristics, along with local climatic factors, yielded a robust mixed-effects model that captured the variations in household water uses with high accuracy at a monthly time-step. Local air temperature, household occupancy level, presence of a swimming pool, the year the household was built, and the efficiency of indoor appliances and irrigation systems were exhibited to be the key factors influencing variations in household water use. The third and fourth chapter of this study reanalyzed the water consumption data of those 126 municipalities. The third chapter dwelled into the estimation of the state of water consumption efficiencies or economics of scale in the municipal water systems using an econometrics framework called urban scaling theory. A parsimonious mixed-effects model that combined the effects of socio-economic, built environment, and regional factors, such as climate zones and water use type, was developed to model annual water uses. The results confirm efficiencies in water systems as cities grow and become denser, with CII water use category showing the highest efficiency gains followed by the Residential and Total water use categories. A key finding is the estimation of the unique variations in water use efficiency patterns across the U.S. These variations are influenced by factors such as population, housing characteristics, the combined effects of climate type and geographical location of the cities, and the type of water use category (Residential or CII) that dominates in each city. The fourth or the final chapter synthesizes the lessons learned previously about the drivers of municipal water uses and explores the development of a model for predicting monthly water consumption patterns using machine learning algorithms. These algorithms demonstrated improved capabilities in predicting the Total monthly water use more accurately than the previous modeling efforts, also controlling for factors with multi-collinearity. Climatic variables (like precipitation and vapor pressure deficit), socio-economic and built environment variables (such as income level and housing characteristics), and regional factors (including climate type and water use type dominance in a city), were confirmed by the machine learning algorithms to strongly influence and cause variations in the municipal water consumption patterns. Overall, this study showcases the power of data-driven approaches to effectively understand the nuances in municipal water uses. Integration of the lessons learned and the statistical frameworks used in this study can empower water utilities and city planners to manage municipal water demands with greater resiliency and efficiency.Item Open Access An economic assessment of white crappie (Pomoxis annularis) culture methods(Colorado State University. Libraries, 2012) Larsen, Erik C., author; Bond, Craig, advisor; Goemans, Christopher, committee member; Myrick, Christopher, committee memberDue to uncertain inputs into production, the development of a successful aquaculture operation requires meticulous business and contingency planning efforts. Given the degree of complexity involved in creating these plans, however, the culturist must often consider and carefully analyze an array of options presented to them. In an effort to assist the culturist with these complicated decisions, the goal of this work is to design a decision support tool, in which the user may explore business planning options and contingency planning scenarios. This decision support tool uses the Habitat Suitability Index (HSI) as an analytical cornerstone in order to estimate the expected output of a white crappie (Pomoxis annularis) culture system (in terms of both number of fish for stocking and dollars of total net revenues). To address stochasticity in production, Monte Carlo simulation tools have been incorporated into the model in an effort to facilitate meaningful economic analyses of production planning on the basis of expected habitat quality.Item Open Access Assessing tradeoffs of urban water demand reduction strategies(Colorado State University. Libraries, 2019) Neale, Michael R., author; Arabi, Mazdak, advisor; Sharvelle, Sybil, advisor; Goemans, Christopher, committee memberIn many cities across the World, traditional sources of potable water supply can become susceptible to shortage due to increased water demands from rapid urbanization and more frequent and extreme drought conditions. Understanding impacts of city-scale conservation and water reuse is important for water managers to implement cost effective water saving strategies and develop resilient municipal water systems. Innovative water reuse systems are becoming more cost effective, technologically viable and socially accepted. However, there is still a need for comparative assessment of alternative sources; graywater, stormwater and wastewater use along with indoor and outdoor conservation, implemented at the municipal scale. This study applies the Integrated Urban Water Model (IUWM) to three U.S. cities; Denver, CO; Miami, FL; and Tucson, AZ. We assess the tradeoffs between cost and water savings for a range of solutions composed of up to three strategies; to understand interactions between strategies and their performance under the influence of local precipitation, population density and land cover. A global sensitivity analysis method was used to fit and test model parameters to historical water use in each city. Alternative source and conservation strategies available in IUWM were simulated to quantify annual water savings. Alternative source strategies simulate collection of graywater, stormwater and wastewater to supplement demands for toilet flushing, landscape irrigation and potable supply. A non-dominated sorting function was applied that minimizes annual demand and total annualized cost to identify optimal strategies. Results show discrete strategy performance in demand reduction between cities influenced by local climate conditions, land cover and population density. Strategies that include use of stormwater can achieve highest demand reduction in Miami, where precipitation and impervious area is large resulting in larger generation of stormwater compared to other study cities. Indoor conservation was frequently part of optimal solutions in Tucson, where indoor water use is higher per capita compared to other study cities. The top performing strategies overall in terms of water savings and total cost were found to be efficient irrigation systems and stormwater for irrigation. While use of stormwater achieves large demand reduction relative to other strategies, it only occurred in non-dominated solutions that were characterized by higher cost. This strategy can be very effective for demand reduction, but is also costly. On the contrary, efficient irrigation systems are frequently part of low-cost solutions across all three study cities. Overall, this study introduces a framework for assessing cost and efficacy of water conservation and reuse strategies across regions. Results identify optimal strategies that can meet a range of demand reduction targets and stay within financial constraints.Item Open Access Characterization of urban water use and performance evaluation of conservation practices using the Integrated Urban Water Model in São Paulo, Brazil(Colorado State University. Libraries, 2018) Batista, Giovana das Gracas, author; Arabi, Mazdak, advisor; Sharvelle, Sybil, advisor; Dozier, Andre, committee member; Goemans, Christopher, committee memberIncreasing urban population around the globe has intensified the need for water, food and energy. The residential sector is responsible for the highest water use in urban settings. Understanding the factors affecting water use helps to improve management strategies, incentivize conservation practices, develop public educational events, feed demand forecasting models and support policy creation. Modelling urban water demand in the long-term is a complex process because of incorporation of multiple dynamic components in the urban-environment system. The Integrated Urban Water Model – IUWM – offers capabilities of long-term modelling by using a mass-balance approach for urban water demand predictions and potential demand reductions assessment. A combination of climate anomalies, water resources management practices over the years and watershed conservation contributed to the water shortage in Southeastern Brazil in 2014-2015. In the city of São Paulo, the shortage was worsened by drops in reservoir levels, rise in water use patterns and in number of inhabitants, and the historical tendency to neglect local water sources. Residential water demand, which accounts for 84% of the total water use, faced compulsory reductions through behavioral changes and reuse of graywater and roof runoff harvesting. The goals of this study are to apply IUWM to the city of São Paulo to quantify savings produced by graywater and roof runoff use and to evaluate the potential of conservation practices for demand reduction. The first part of the study focuses on exploring differences in water demand patterns under shortage conditions using a water use time-series from 2013-2017. In this part, IWUM is trained to estimate indoor and outdoor demand through calibration procedures. Determinants of water demand are also investigated through a multiple linear regression, which identified household size and socioeconomic variables as having a significant effect in water use. The second portion focuses on applying IUWM to evaluate reductions during the shortage and performance of graywater, stormwater, roof runoff harvesting and effluent reuse for potable and non-potable purposes. Climate change was added to assess shifts in performances of conservation practices due to future reductions in precipitation. Lastly, a comparison of maximum potential and benefits of fit-for-purpose technology adoption is done using a cost-benefit matrix. The matrix was adapted for required treatment representing cost and percentage reductions in water demand as benefit. The results of this work support decision-making with respect to conservation practices adoption by enhancing the list of options to manage water demand, especially during shortage conditions. Ultimately, these results can encourage development of water reuse policies in Brazil.Item Open Access Comparative profitability of irrigated cropping activities for temporary water transfers(Colorado State University. Libraries, 2019) Kelley, Timothy, author; Mooney, Daniel, advisor; Goemans, Christopher, committee member; Andales, Allan, committee memberIn response to a projected gap in water supply and demand, Colorado's Water Plan calls for up to 50,000 acre-feet of temporary water transfers from agricultural to municipal and industrial uses by 2030. Water stakeholders, however, want to avoid buy and dry scenarios, implying that a portion of agricultural water-right holders' consumptive use (CU) should remain available for on-farm agricultural production. Alternative Transfer Methods (ATMs) represent the regulatory mechanisms that enable temporary water transfers without permanent drying of agricultural land. To participate in an ATM, water-right holders must first establish a historical consumptive use (HCU) baseline which can then be allocated to agricultural production or temporary transfer. When faced with less water, producers may pursue several management options, including: rotational fallow, deficit irrigation, changes to crop mix, or changes to other practices like harvest timing. Yet, previous research on the risk profile of these options and their effect on producers' expected adaptation behavior is limited. This research develops a framework to compare the expected profitability of irrigated cropping activities, and in doing so, accounts for differences in risk and water-leasing potential. The framework is applied to a case study of twelve selected irrigated cropping activities on a well-drained silt loam soil in northeastern Colorado using stochastic enterprise analysis. Specifically, we compare gross margins for two corn (grain and silage) and two alfalfa (two cut and three cut) cropping enterprises on a per water-unit basis (one unit equals 12.94 acre-inches of CU); each under full irrigation, deficit irrigation, and partial fallow water management strategies. First, we simulate producers' expectations about gross margins based on empirical distributions of precipitation, price, and cost data for 1992 – 2017 and the FAO crop water production function. Second, we employ econometric analysis of the first, second, and third moments of the simulated gross margin distributions to estimate a risk premium for each activity. Fully-irrigated corn is set as the reference activity (one acre requires 1 water-unit of irrigation or 12.94 acre-inches of CU) and we find that crop choice, harvest timing, and deficit/fallow strategies all significantly affect producers' risk exposure relative to the reference activity. Activities remaining in the efficient set are primarily the rotational fallow strategies which would enable 3.24 – 7.14 acre-feet of CU to be leased for every twelve water-units of their HCU baseline enrolled in an ATM at a breakeven cost of $386.05 to $791.51 per acre-foot. More land could be maintained in agricultural production for an identical amount of transferable water under deficit irrigation, but it would typically come at a higher breakeven cost of $381.95 to $850.19 per acre foot depending on the producers' choice of crop and harvest strategies. The results should be of interest to academic, producer, and policy audiences, respectively, as they provide insight on (i) a novel methodology for comparing irrigated cropping activities that incorporates expected profitability, risk, and leasable water into a single metric, (ii) a ranking of potential adaptation strategies for producers who participate in ATMs, and (iii) insight into the economic tradeoffs between maintaining agricultural working land while also allowing for temporary water transfers to other beneficial uses.Item Open Access Development of a cost effective and energy efficient treatment system for graywater reuse for toilet flushing at the multi-residential scale(Colorado State University. Libraries, 2012) Hodgson, Brock, author; Sharvelle, Sybil, advisor; Roesner, Larry, committee member; Goemans, Christopher, committee memberA growing population increases water demand in many metropolitan areas resulting in the need for projects, like graywater reuse, that free up water supply or decrease water consumption. Plumbing for graywater collection from showers and bathroom sinks has been separated from blackwater collection in 14, two-person units at a residence hall at Colorado State University. Treatment technologies were evaluated for the ability to provide safe and cost effective onsite reuse of graywater for toilet flushing. The goal is to develop a system with low use of energy and consumables capable of treating graywater to a quality safe for toilet flushing. The system analyzed filtration utilizing coarse, sand (20-40 microns), or cartridge (100 microns) filtration and the disinfection potential of ultraviolet (UV) with hydrogen peroxide (H2O2), chlorine, UV with chlorine as a residual, or ozonation with chlorine as a residual. Disinfection efficacy was determined by measuring general water chemistry parameters in addition to concentration of E. coli and total coliforms. The influent E. coli averaged 10 2.7±1.1 CFU/100mL and total coliform averaged 10 7.9±1.2 CFU/100mL. Effluent E. coli was reduced to non-detectable concentrations for UV combined with H2O2 and chlorine, but only chlorine measured non-detectable concentrations of total coliform. At the tested doses, ozone combined with chlorine and UV combined with chlorine resulted in limited or no removal of E. coli and total coliforms. Higher doses may prove to provide more efficient disinfection but require more expensive equipment and may impact the projects feasibility. Based on data collected, chlorine appears to be a better approach for disinfection of graywater. None of the disinfectants significantly affected graywater chemistry, but all reduced odors with the exception of UV. There was no significant change of water chemistry as a result of coarse or cartridge filtration. Sand filtration significantly reduced turbidity, total suspended solids (TSS), total organic carbon (TOC) and biochemical oxygen demand (BOD5) by 13±11%, 37±12%, 31±17% and 21±9% respectively. Despite the decrease of TSS and TOC, the sand filter resulted in an increase chlorine demand. As a result, it was concluded that the most effective treatment alternative is incorporation of coarse filtration followed by chlorine disinfection. The health and environmental concerns associated with chlorine disinfection can be minimized by utilizing ammonia in graywater to favor monochloramine formation which results in a smaller dose. Additionally, the influent specific UV absorbance of 1.1±0.6 indicates reduced risk of disinfection by-product formation. The cost, including capital and operation, of implementing various filtration and disinfection approaches along with the total life-cycle project cost at various system sizes were evaluated. At the residence hall scale, the most cost effective disinfection approaches include application of liquid chlorine, ultraviolet with chlorine as a residual, and small-scale ozonation with chlorine as a residual. The cost of the hydrogen peroxide dose rendered its use infeasible. The cost effective filtration approaches were coarse, sand (20-40 microns), and cartridge (100 microns) and the associated capital for each filter did not have a large impact on the life-cycle cost. Graywater reuse for toilet flushing proved financially beneficial particularly in regions with high domestic water costs and at system sizes that reuse ≥1,000 gpd. These projects can be financially feasible and have low payback periods in addition to indoor water use reduction.Item Open Access Economic and environmental trade-offs of irrigation best management practices in the Lower Arkansas River Valley(Colorado State University. Libraries, 2017) Orlando, Anthony, author; Hoag, Dana, advisor; Goemans, Christopher, committee member; Gates, Timothy K., committee memberThe flows of the Arkansas River cascade through the Rocky Mountains and spill into Colorado's eastern plains. In the Lower Arkansas River Valley (LARV), these flows serve irrigators on over 250,000 acres, and are critical to the production of everything from corn to cantaloupes. Concurrent to the "goods" produced with this irrigation, are a series of "bads" occurring in the form of pollution. Elevated selenium, nitrate, and salinity concentrations have been related to high volumes of irrigation return flows, and threaten compliance with the Arkansas River Compact. Implementing a series of regional land and water Best Management Practices (BMPs) is thought to reduce the negative impacts ("bads") of irrigated agriculture in the region and in some cases, increase the productivity of land and water ("goods"). A deeper understanding of impacts of proposed BMPs is required. The specific question I hope to answer with this thesis is "What are the economic and environmental trade-offs face by Lower Arkansas River Valley producers when implementing a series a land and water best management practices?" To answer this question, an economic linear programming (LP) model is written to maximize regional net returns for a representative area within the LARV, using the General Algebraic Modeling System (GAMS). The LP is calibrated to match the physical characteristics of the region, historic water application volumes, and the historic crop mix. BMPs are tested by constraining various equations in the model, resulting in a series of economic measures. These economic measures are then compared to the output of a water flow, and reactive solute transport model to quantify the trade-offs that exist between regional net returns, in-stream selenium concentrations, in-stream nitrate concentrations, and yield losses to soil salinity. The results of this analysis suggest the existence of win-win scenarios, which increase net returns, and reduce pollution concentrations. No single BMP outperforms all others, supporting the notion that LARV producers and water policy makers face trade-offs in their efforts to control irrigation-induced pollution.Item Open Access Effectiveness and acceptability of congestion pricing(Colorado State University. Libraries, 2015) Janusch, Nicholas Roger, author; Kroll, Stephan, advisor; Goemans, Christopher, committee member; Loomis, John, committee member; Mushinski, David, committee memberUrban congestion is a pervasive and growing problem in developed and developing countries. The lack of excludability for scarce urban space, specifically roads and parking spaces, creates a common resource problem yielding a congestion externality that generates many external costs. Marginal social cost pricing has long been advocated as a means of alleviating market failures resulting from such negative (environmental) externalities. Congestion pricing comes in numerous forms (e.g., tolls on roads or express lanes), but has only been sporadically adopted despite congestion being a growing problem. The literature argues that concerns on equity and fairness issues and revenue redistribution are major hurdles of making an effective congestion pricing policy politically feasible and publicly acceptable. This dissertation investigates the effectiveness and acceptability of congestion pricing schemes in different contexts and examines whether individual beliefs in addition to the objective welfare effects determine voter acceptability. The first chapter employs laboratory experiments to examine the evolution of voting behavior after individuals become accustomed to the congestion problem and the congestion pricing policy, and the nature of the experience from the congestion policy. The congestion pricing policy exogenously creates inequitable outcomes which in some cases makes some people worse off. The second chapter develops and examines a three-player bottleneck congestion game and examines the ex-ante and ex-post welfare implications of an \textit{ex-ante} efficient tolling policy. The third chapter examines the effectiveness and acceptability of tolls in the three-player bottleneck congestion game using laboratory experiments where equity concerns are endogenously determined. The results suggest policymakers should be open to and considerate of the equity effects, the characteristics and beliefs of their constituents, and how to earmark revenues before implementing efficiency enhancing environmental policies.Item Embargo Integrated assessment of water shortage under climate, land use, and adaptation changes in the contiguous United States(Colorado State University. Libraries, 2024) Gharib, Ahmed AbdelTawab Fahmy AbdelMeged, author; Arabi, Mazdak, advisor; Goemans, Christopher, committee member; Sharvelle, Sybil, committee member; Warziniack, Travis, committee memberWater scarcity is a critical global challenge. Water managers pursue water supply- and demand-side strategies, including construction or enhancement of water supply systems, conservation, and water reuse, to address water security driven by changes in climate, population, and land use. However, the effects of these strategies to mitigate future water shortages under dynamic climate and socioeconomic conditions at various spatial and temporal scales remain unclear. The overarching goal of this dissertation is to (1) improve understanding of the interconnections and interactions between climate, socioeconomic, hydrological, and institutional factors that influence water shortage at the river basin level, and (2) conduct an integrated assessment of water and land use management strategies. The dissertation is organized into three research studies. The first study explores water shortages in the South Platte River Basin (SPRB) and the potential benefits of investing in storage infrastructure and demand management strategies. The second study develops a methodology to understand the interactions between land use planning, water demands, shortage vulnerability, and effects on associated economic value. The third study expands the integrative assessment framework to assess changes in water demand, supply, and withdrawals, and identify effective mitigation strategies across river basins in the Contiguous United States over a range of climatic and socioeconomic pathways that are forecasted for the coming decades. In the first study, we develop data analysis and modeling tools to project water demands, supply, and shortages in the SPRB by the mid and end of the 21st century, examine the efficacy of adaptation strategies to reduce water shortages, and explore conditions under which reservoir storage and demand management would serve benefits for reduction of the vulnerability of economic sectors to water shortages. We implement two demand modeling tools to simulate the current and future urban and agricultural water demand in the river basin. Water yield is simulated using calibrated and tested Variable Infiltration Capacity (VIC) model. The estimated water demands and supplies are integrated using the Water Evaluation and Planning (WEAP) model to simulate water allocation with a half-monthly timestep to 70 aggregate users in the basin. Population growth, climate change, reservoir operations, and institutional agreements were considered during the modeling. The study reveals that the vulnerability to water shortages across sectors would increase without adaptation strategies. Population growth tends to be the primary driver of water shortages in the river basin. Reservoirs in the basin can relieve the sequences of the earlier seasonal shift of the water supply by capturing water during the high flow to be used in the high-demand seasons. However, additional storage is only beneficial up to a threshold of storage capacity to the water supply mean ratio of 0.64. The second study focuses on integrating the effects of land use planning and water rights institutions into the shortage analysis of the SPRB. The goal is to build a framework to understand the complex interactions between climate change, water rights institutions, urban land use planning, and population growth, and how they collectively impact the water shortage and economic analysis. We apply this framework to the SPRB simulate three water institutions, update the urban demand modeling to be a function of the population density, and test different scenarios of population locations throughout the basin. Results show that changing water rights institutions has a small impact on total shortages compared to climate change, but substantially impacts which users experience shortages. Land use policies influencing population locations have larger impacts on shortage and economic value compared to water rights. Finally, distributing the population more evenly between upstream and downstream regions reduces water shortages and increases associated economic value regardless of water rights institutions and climate conditions. The third study employs an integrative modeling assessment framework to assess water shortage and effective mitigation strategies in river basins across the Contiguous United States. The goals are to improve the methodologies for estimation of water withdrawals, consumptive use, and water shortage, and explore the effectiveness of supply- and demand-side adaptation strategies. The simulated demands are integrated with the water supply components (groundwater, interbasin transfers, water yield, and reservoirs) into a water allocation model for simulating shortage under different scenarios. Results reveal that irrigation has the highest historical and future consumptive use, over 75% of the total consumptive use. Although the consumptive use ratio receives little attention in the literature, it appears to be the most significant parameter for shortage calculations. The allocation model provides comprehensive shortage analysis considering shortage volume, ratio, and frequency across multiple scenarios for the 204 sub-regions –Hydrologic Unit Code 4 watersheds– of the Contiguous United States. Water shortages concentrate between the boundaries of the West Region with both the Midwest and the South regions, in addition to Arizona, Florida, and the center valley of California. Relying only on sustainable groundwater pumping rates is essential to stop the ongoing groundwater depletion, but adds more pressure on demand reduction strategies. The ongoing research examining water demand, supply, and shortage is important and requires further integration of the key influencing variables. This dissertation demonstrates the necessity of an integrated approach to fully understand the relative impacts of the main drivers of water allocation and shortage. We highlight that reservoirs play a vital role in balancing seasonal fluctuations in the water supply. However, their effect on the 30-year mean annual shortage is effective until the storage volume ratio to mean water supply exceeds 64%. Additionally, land use policies carry higher direct significance on water shortages compared to water rights. We find that distributing the population more evenly throughout the river basin provides the lowest shortage. Lastly, the approaches targeting shortage calculation and mitigation should analyze both regional and national scenarios under integrated frameworks comparing demand- and supply-side options.Item Open Access Integrated water resources management under uncertainty: exploring interconnected technological, infrastructural and institutional solutions(Colorado State University. Libraries, 2018) Wostoupal, Benjamin, author; Arabi, Mazdak, advisor; Goemans, Christopher, committee member; Dozier, André, committee memberRapidly growing populations in many of the world's semiarid regions intensify competition for increasingly scarce freshwater resources. Growing urban demands, land-use change, and a changing climate will further exacerbate regional vulnerability to water scarcity. The intensification of these trends creates several challenges for the future planning and management of water resources. In this work we employ the use of an integrated socioeconomic, hydrologic, and ecological modeling framework to quantify the effects of water rights allocation on a representative semiarid river basin. Through this framework we analyze the tradeoffs of several water management practices, institutional settings, and regional policies on municipal and agricultural sectors. Generally, the agent-based adoption of water management strategies can alleviate the harm of water scarcity while providing positive feedbacks to reducing municipal costs and increasing agricultural profit from production. Household adoption of xeriscaping is considered the most important technology to lower urban demands and offset the negative externalities of rural-to-urban water transfers. Additionally, an uninhibited water market leads to the most effective allocation of water rights, providing benefits to both rural and municipal communities. The future allocation of water rights under climatic, institutional, agricultural, and technological uncertainty shows significant sensitivity to fluctuations in water conveyance infrastructure costs. Such changes in infrastructure costs (i.e. 50% to 150%) can nearly double the expected costs of reliably supplying water to urban households. However, urban water supply planners can incentivize the adoption of water management practices to stabilize these costs. Further, required water purchases for land developers set by urban planners can be used as a key policy tool for keeping costs low. This work contributes to existing literature in integrated water resources management to help understand the effects of water scarcity and provide practical solutions for urban water planners in rapidly urbanizing semiarid regions.Item Open Access Quantifying the relationship between irrigation activities and wetlands in a northern Colorado watershed: assessing this added value of irrigation(Colorado State University. Libraries, 2012) Smith, Meagan Blake, author; Arabi, Mazdak, advisor; Fontane, Darrell, committee member; Goemans, Christopher, committee memberThe construction over the past 130 years of an extensive canal system throughout Colorado has allowed for the spread of irrigated agriculture further and further from the water source. Irrigation activities and associated return flows serve multiple benefits to the surrounding ecosystem health and function, specifically the creation and maintenance of wetlands that would otherwise not exist. This research aims to quantify the relationship between cropland irrigation and down gradient "incidental" wetlands, to allow for the valuation of ecosystem services provided by water in agriculture. Non-linear and multiple-linear regression analyses were used in combination to explain the variability in the size of "incidental" wetlands in a northern Colorado watershed, in response to irrigation application and infrastructure within the contributing areas of each wetland. The explanatory variables included amount of area under flood and sprinkler irrigation, irrigation conveyance structures, and controls for heterogeneities in the landscape, including runoff potential and shallow groundwater flow potential. The analyses were performed using aggregated landscape properties at various distances from the edge of the wetlands, from 50 m to 500 m, in an attempt to identify a spatial area of influence for irrigation activities in the study area. Further analyses included evaluating the impact of changing irrigation scenarios on the size of "incidental" wetlands. The simulated scenarios included increasing application efficiency by converting all flood irrigated lands to sprinkler irrigation; and increasing conveyance efficiency by lining all existing canals. Research findings include (i) the most significant explanatory variables, irrespective of distance from wetland, were amount of flood-irrigated lands and length of irrigation conveyance structures, (ii) irrigation activities within 200 m of a wetland explained the greatest variability in wetland size (R2adj = 0.50), (iii) increasing runoff potential in the contributing areas, represented by area-weighted curve number values, increased the impact of irrigation variables on the size of "incidental" wetlands, and (iv) increasing irrigation efficiencies in the study area consistently resulted in decreasing total wetland area. Furthermore, an ecosystem benefits transfer model was utilized to estimate the dollar value of the ecosystem services provided by the "incidental" wetlands in the study area. At an estimated value of $5,647/ha, the ability to evaluate the impact of changing irrigation practices on nearby wetlands may influence the decision process of both landowners and water planners.Item Open Access Spatial dimensions of natural resource decisions: private responses to public resource decisions(Colorado State University. Libraries, 2012) Goldbach, Rebecca, author; Davies, Stephen, advisor; Thilmany, Dawn, advisor; Goemans, Christopher, committee member; Weiler, Stephan, committee memberThis dissertation illustrates how the use of spatial economics, as opposed to non-spatial methods, can enrich economic research related to natural resources decision-making. This research encompasses three distinct, but complementary, papers, based on two datasets that vary in richness and scale, and one data-driven model that will detail how data will need to be collected to inform natural resource infrastructure projects in a developing economy. The first essay uses cutting-edge spatial econometric techniques to evaluate the location decisions of private outdoor recreation providers. Here, I find clustering of outdoor recreation opportunities and that private providers are attracted to areas with existing public outdoor recreation opportunities when making their own location decisions. The second essay focuses on a specific form of privately provided outdoor recreation, agritourism, and again finds that the more existing outdoor recreation, the more agritourism trips will be taken. The second essay uses a hurdle travel cost model and focuses on the demanders, as opposed to the suppliers, of private outdoor recreation. The findings reveal that agritourists gain substantial consumer surplus (with averages ranging from $93 to $465) from their trip, and that the model treatment of multi-destination agritourists impacts the estimated consumer surplus. The first two papers use author-created outdoor recreation measures that are introduced in this dissertation. These measures were created to complement the USDA-Economic Research Service Natural Amenities Index, with input from the creators of the Natural Amenities Index, and have potential to be used in many natural resource and economic development studies as the Natural Amenities Index has been. In contrast to the other essays, the third essay recognizes that spatial relationships can be important in evaluating an economic question, even when dense spatial datasets are not available. The study uses an Equilibrium Displacement Model to evaluate water management and storage policies for a canal system in Afghanistan, a country where war and poverty have damaged infrastructure and made it difficult to collect accurate data. Producers' spatial location on the canal is of key importance to understanding their decisions and the failure to account for these spatial relationships could lead to misinformed policy decisions. The Equilibrium Displacement Model results show that water management and storage policies have different impacts on producers based on their spatial location on the canal. Through the use of three very different models, this dissertation illustrates the importance of incorporating spatial impacts when evaluating policies related to natural resources.Item Open Access Study to analyze the viability of rainwater catchment from roofs for its reuse in Tegucigalpa, Honduras(Colorado State University. Libraries, 2012) González, Ana Carolina, author; Sharvelle, Sybil, advisor; Roesner, Larry A., committee member; Goemans, Christopher, committee memberWater scarcity is a problem in many parts of the world. In some regions, there is physical water scarcity because there are not enough resources of water to supply the increasing demand, while other parts of the world have an economic scarcity, where resources are more abundant but poor governance and other problems render water unavailable for most of the population. Where the problem is economic water scarcity, there are many solutions that could ameliorate the problem, but most times the solutions require a change in government, more economic resources and a better willingness. Solving the problem requires long-term changes; however the need for water is immediate. This is why many methods have been developed for water storage and reuse, however because the problem is not a lack of water but poor management, implementing and maintaining systems is simply not a reality in many parts of the world, particularly in Africa and Latin America. Water supply systems in Honduras provide service to approximately 86% of the total population (WHO/ UNICEF 2010), however the service is not continuous, and the quality of the water supplied is not high enough to be considered potable. Simple mechanisms that address urgent problems have had to be used to supply citizens with water. Rainwater catchment or rainwater harvesting is one option worth analyzing for the capital city of Honduras, Tegucigalpa. Rainwater catchment systems are a simple solution that can be adopted in many parts of the country; many houses are already equipped with storage tanks and catching rainwater would require only a basic catchment system and make the most from the natural resources available. Stored rainwater can serve as a supplement to the city's supply system or as sole source of water for many growing areas that are not connected to the water supply network. Other alternatives include graywater reuse, well drilling and communal water storage tanks. For this study, household scale rainwater catchment systems were analyzed, where water can be channeled through pipes installed on each roof. The pipes transport water either to an underground or elevated tank, which many houses in Tegucigalpa already have. Water samples were collected from rooftops of different materials in three different locations and tested according to the Honduran regulation to analyze the quality of water. Precipitation data for Tegucigalpa was used to determine the amount of water that can be collected in order to compare this with the costs of implementing household scale rainwater catchment systems and determine whether it is a feasible solution for water scarcity in Tegucigalpa. In the end, all aspects were analyzed to determine whether this could be a solution worth implementing in Tegucigalpa to alleviate water scarcity problems as well as the possible positive and negative impacts it would have on the economy, society and the environment. Based on the analyses performed, it becomes clear that rainwater harvesting is not the one answer that will solve all water scarcity issues in Tegucigalpa. Storage tanks would need to be much larger, precipitation more abundant, roofs would have to have a bigger area and tanks be cheaper for it to be the sole source of water supply in the city. However, though maybe not ideal, it may be used as complementary to current public and private supply systems; it can reduce water bills and increase the supply in some areas of the city. It might be good investment for families that buy water from private companies and for homes where there already is a tank installed for water supply and storage.Item Open Access The value of water in agriculture: a typology of water valuation methods and estimate of economic activity from water in agriculture and associated mutual uses in the Arkansas River Basin, Colorado(Colorado State University. Libraries, 2013) Salcone, Jake, author; Pritchett, James, advisor; Goemans, Christopher, committee member; Shields, Martin, committee memberThe waterstressed Arkansas River Basin is experiencing a greater frequency of water transfers from agriculture to municipal and industrial uses. Removing water from agriculture may harm rural communities, impact ecosystems, and change recreation opportunities. In order to better understand the implications of transfers, the economic activity created by these water uses must be calculated. Previous water valuation efforts have neither included all stakeholder interests, nor quantified externalities of water allocation scenarios and thus do not accurately estimate the potential impact of transfers. This paper evaluates methods for calculating the value of water in agriculture, the value of water to recreational users, the economic spillovers from agriculture and recreation, and the value of environmental flows. Direct, indirect and induced economic activity from agriculture is estimated using IMPLAN; economic activity from recreation related to agricultural water is estimated using benefit transfer and IMPLAN. Implications to ecosystem benefits are described quantitatively. Impacts to economic activity in the region from potential reductions in irrigated acreage are considered, including hypothetical impacts from reduced water recreation. The results show that the vast majority of agriculture, and thus economic activity from agriculture, depends upon irrigation water. That said, irrigated crop farming makes up just 1% of employment and economic activity in the Arkansas Basin. However, the great quantities of water that are allocated to agriculture (almost 90% of all water withdrawn from basin water ways) offer recreation opportunities that generate employment and economic activity and support agro-ecosystems that have economic and consumer surplus benefits.