Low streamflows and warm stream temperatures, caused mainly from agricultural diversions, currently limit available habitat and productivity of trout, including native Lahontan cutthroat trout in Nevada’s Walker River Basin. Environmental water purchases, which transfer water from willing sellers to instream uses (i.e for fish), are being evaluated to improve instream habitat. To determine which environmental water purchases to prioritize, this study was undertaken to build a computer model in order to simulate stream temperatures under differing environmental water transfer scenarios. Model runs simulate a range of environmental water transfers at major diversions and reservoirs throughout the Walker River Basin. Results indicate that low flows generally coincide with critically warm stream temperatures, cooler stream temperatures exist in the East Walker River, a tributary of the Walker River, during warm seasons which provide good habitat for fish, environmental transfers can improve stream temperatures for some highly impacted reaches by up to 3°C in dry years, and environmental water transfers have a greater effect in dry years than wet years.

This dissertation develops, tests and validates statistical methods for verifying the amount of water conserved as a result of investments in precision leveling, other on-farm conservation measures in place, weather variation and farmer behavior. This evaluation uses a sample of 328 unique fields from Lakeside Irrigation Division in Texas over a six-year period, totaling 966 observations. Results show that precision leveling accounts for a 0.30 acre-feet reduction of irrigation water per acre leveled. This Mixed-Level Model (MLM) estimate for precision leveling water savings is more precise than the estimates either from an Ordinary Least Square Model or a Fixed Effect Model. A meta analysis combines the results from this model with other similar studies. Although the mean estimate of the meta-analysis is similar to the MLM estimate, the meta-analysis further reduces the standard error of the mean precision leveling estimate by 2 percent. A better approximation of the acre-feet water savings per acre farmed translates into less uncertainty for water regulators, managers and policymakers regarding the volume of conserved water that is available for transfer. / text

This dissertation comprises theoretical and empirical models to manage watersupply risk in irrigated agriculture. While irrigation is by itself a strategy to regulate thesupply of water for farm use, water systems that depend on surface water sources are stillsubject to the random inflows that feed their reservoirs. Depending on the size of thereservoir, the demand for irrigation, and the seasonal distribution of inflows, wateravailability may decrease to levels that severely constraint agricultural production. Thisdissertation begins with a theoretical examination of on-farm cropping decisions underwater endowment risk. However, the analysis is extended to the use of a risk-sharinginnovation to transfer the water availability risk outside an irrigation district. Specifically,the design, use, and economic feasibility of an inflow-based derivative are studied for theRio Mayo irrigation district, located in Northwestern Mexico.On the theoretical front, the analysis consists of modeling the on-farm economicsof hedging against uncertain irrigation endowments. The basic model starts by analyzingthe role of crop diversification. As expected, the firm responds to higher degrees of risk,as measured by the variance in the supply of water, by allocating less land towards thewater-intensive crops. The underlying motivation in these strategies is the need to avoidthe relatively larger reductions in productivity sustained by water-intensive cropportfolios. However, crop diversification comes at the cost of reduced profits. As analterative to crop diversification, the model is modified to study the role of an institutionthat transfers water contingent on the states of nature. The extension shows that, undercertain conditions, enrolling in such a scheme produces the same profit as undercertainty.In the empirical component of the dissertation, the economics of an inflow-basedderivative are examined. The modeling strategy consists of simulating the economicenvironment and hydrological profile of the Adolfo Ruiz Cortinez Reservoir on the RioMayo irrigation district. Specifically, a stochastic dynamic simulation model is developedthat captures the intra and inter seasonal risk aspects associated with water risk and wateruse for irrigated agriculture. The results indicate that the inflow-based derivative is aviable instrument in the terms of affordability (i.e. premiums) and yield effective incomeprotection (i.e. risk reduction).

abstract: The act of moving water across basins is a recent phenomenon in Arizona water policy. This thesis creates a narrative arc for understanding the long-term issues that set precedents for interbasin water transportation and the immediate causes--namely the passage of the seminal Groundwater Management Act (GMA) in 1980--that motivated Scottsdale, Mesa, and Phoenix to acquire rural farmlands in the mid-1980s with the intent of transporting the underlying groundwater back to their respective service areas in the immediate future. Residents of rural areas were active participants in not only the sales of these farmlands, but also in how municipalities would economically develop these properties in the years to come. Their role made these municipal "water farm" purchases function as exchanges. Fears about the impact of these properties and the water transportation they anticipated on communities-of-origin; the limited nature of economic, fiscal, and hydrologic data at the time; and the rise of private water speculators turned water farms into a major political controversy. The six years it took the legislature to wrestle with the problem at the heart this issue--the value of water to rural communities--were among its most tumultuous. The loss of key lawmakers involved in GMA negotiations, the impeachment of Governor Evan Mecham, and a bribery scandal called AZScam collectively sidetracked negotiations. Even more critical was the absence of a mutual recognition that these water farms posed a problem and the external pressure that had forced all parties involved in earlier groundwater-related negotiations to craft compromise. After cities and speculators failed to force a bill favorable to their interests in 1989, a re-alignment among blocs occurred: cities joined with rural interests to craft legislation that grandfathered in existing urban water farms and limited future water farms to several basins. In exchange, rural interests supported a bill to create a Phoenix-area groundwater replenishment district that enabled cooperative management of water supplies. These two bills, which were jointly signed into law in June 1991, tentatively resolved the water farm issue. The creation of a groundwater replenishment district that has subsidized growth in Maricopa, Pinal, and Pima Counties, the creation water bank to store unused Central Arizona Project water for times of drought, and a host of water conservation measures and water leases enabled by the passage of several tribal water rights settlements have set favorable conditions such that Scottsdale, Mesa, and Phoenix never had any reason to transport any water from their water farms. The legacy of these properties then is that they were the product of the intense urgency and uncertainty in urban planning premised on assumptions of growing populations and complementary, inelastic demand. But even as per capita water consumption has declined throughout the Phoenix-area, continued growth has increased demand, beyond the capacity of available supplies so that there will likely be a new push for rural water farms in the foreseeable future. / Dissertation/Thesis / M.A. History 2013

Les horizons d'accumulations carbonatées (HAC) de Champagne sont des horizons particuliers présents de manière non systématique dans les profils de sol directement sous l'horizon organo-minéral. Bien que des travaux antérieurs se soient déjà attachées à l'étude de ces structures particulières, certaines questions restent encore en suspens, notamment en ce qui concerne leur localisation dans le cadre régional, leur caractérisation par rapport aux autres horizons du profil et la quantification de leur rôle dans les transferts hydriques. Leur localisation sur le terrain n'étant pas réalisable méthodes de prospection habituelles (pénétrométrie dynamique, tarière), les zones de localisation préférentielle des HAC ont été déterminées par une exploration bibliographique. Des analyses en laboratoire ont été conduites sur des échantillons prélevés sur un site pilote représentatif, le Mont du Ménil (08). En plus des analyses géochimiques et de la colorimétrie, les échantillons prélevés tout au long des profils ont subi des analyses pétrophysiques habituellement utilisées dans la caractérisation des pierres en œuvre (porosité totale à l'eau, porosimétrie mercure, cinétiques d'absorptions capillaires et d'évaporation). Ces analyses montrent que les HAC sont bien différents des horizons sus et sous-jacents. Ce sont des niveaux présentant une forte porosité qui va de pair avec leur induration plus faible contrairement à ce qui est généralement admis dans la bibliographie. Les HAC présentent également des micromorphologies différentes des autres horizons du profil pédologique ce qui justifient les réseaux poreux différents identifiés. L'étude des transferts hydriques en laboratoire montre également que ces réseaux poreux différents sont responsables de transferts hydriques plus rapides dans les HAC que dans leurs grèzes d'accueil. Il apparaît donc que contrairement à ce qui est généralement avancé dans la littérature, les HAC champardennais ne semblent pas faire obstacle aux transferts hydriques mais semble au contraire les favoriser. Ce phénomène pourrait avoir des conséquences agronomiques importantes favorisant le drainage et les remontées capillaires. / Carbonate accumulation horizons (CAH) are structures un-systematically present in Champagne-Ardenne soils (NE of France) and are localized directly under de rendic leptosol. They have already been studied but their regional repartition, characterization compare to other soils horizons and impact on water transfers remain unknown. On the field, CAH cannot be directly localized by currently prospection methods. Preferential location areas have been determined by literature analyze. Geochemistry, colorimetry and petrophysical analyzes (total water porosity, mercury porosimetry, absorption en evaporation kinetics tests) have been applied on samples took on a representative site : Mont du Ménil. These analyses have shown that CAH present a high porosity linked to their weak induration contrary to what is generally advanced in the literature. The micromorphology of CAH is different from others horizons that induces porous network différences. Laboratory water transfers study links these porous network differences to faster water transfers measured for CAH contrary to the others horizons. CAH of Champagne do not impede water transfers contrary to what is generally fund into the literature but seems to favor them. This phenomenon could have important agronomic implications favouring draining and capillary rises.

This study developed a general framework that can be applied to integrating environmental sustainability aspects into economic development planning in the case of exploiting water resources through inter-basin water transfers (IBWT). Using the Lesotho Highlands Water Project (LHWP) between Lesotho and South Africa (SA), the study used the multi-country ecological social accounting matrix (MC-ESAM) for Lesotho and SA to integrate ecological implications of the LHWP with the economic benefits of the project. The study further used the developed MC-ESAM multipliers to analyse the impact of lost ecological services downstream the LHWP dams in Lesotho on the wellbeing of households directly affected by the project in Lesotho and the general economies of Lesotho and SA. The MC-ESAM multipliers were also used to analyse different policy scenarios aimed at compensating affected households in Lesotho for ecological losses. The results revealed that while the LHWP has significant direct and indirect benefits in terms of social and economic development in Lesotho and SA, the project has serious unitended impacts on ecological resources and services, with resultant deleterious wellbeing implications for populations residing within the reaches of the LHWP rivers and downstream the LHWP dams in Lesotho. The results from the MC-ESAM multiplier analysis indicated that not only the income of populations directly affected by the project in Lesotho is likely to fall, but also that of other households and social groups, as well as the general economies of Lesotho. Also, because of economic dependence of Lesotho on SA in terms of imports, SA will also loose. The policy simulation results showed that compensating the ecological losses would greatly improve the welfare of directly affected populations and the rest of Lesotho economy. The empirical analysis and policy simulations results showed relatively small impacts in general, but were significant for groups of people directly affected by the project in Lesotho. The study demonstrated the importance of integrating ecological consequences into impact assessment of IBWT before such transfers can be implemented to ensure Pareto optimality and of considering economy-wide impacts and multi-sector, multi-country linkages associated with IBWT for a holistic impact assessment of IBWT. / Thesis (PhD (Agricultural Economics))--University of Pretoria, 2007. / Agricultural Economics, Extension and Rural Development / unrestricted

Human impacts from land and water development have degraded water quality and altered the physical, chemical, and biological integrity of Nevada's Walker River. Reduced instream flows and increased nutrient concentrations affect native fish populations through warm daily stream temperatures and low nightly dissolved oxygen concentrations. Environmental water purchases are being considered to maintain instream flows, improve water quality, and enhance habitat for native fish species, such as Lahontan cutthroat trout. This study uses the River Modeling System (RMSv4), an hourly, physically-based hydrodynamic and water quality model, to estimate streamflows, temperatures, and dissolved oxygen concentrations in the Walker River. Stream temperature and dissolved oxygen changes were simulated from potential environmental water purchases to prioritize the time periods and locations that water purchases most enhance stream temperatures and dissolved oxygen concentrations for aquatic habitat. Environmental water purchases ranged from 0.03 cms to 1.41 cms average daily increases. Modeling results indicate that increased water purchases generally affect dissolved oxygen in two ways. First, environmental water purchases increase the thermal mass of the river, cooling daily stream temperatures and warming nightly temperatures. This prevents conditions that cause the lowest nightly dissolved oxygen concentrations (moderate production impairment thresholds are

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: South Africa‟s hydrological and geographical characteristics, coupled with the location of a large part of its mineral endowment, required the development of the complex Vaal River Supply System, including inter-basin water transfer (IBT) projects which have been in operation for over twenty-five years. This research compares the actual water transfers of two such IBTs with their original, appraisal stage, predictions. Transfers are shown to be significantly less and also more variable than predicted. Further research reveals that the state of the receiving system has a large bearing on year-to-year decisions regarding transfers. Past appraisals, following what is called the Incremental Approach, do not adequately consider the likely future inter-basin transfer operating regime. Examination of six case studies, four South African, one Chinese and one Australian, shows that the Incremental Approach is still in general use – despite tools available for an improved approach. A new approach is proposed to upgrade estimations of variable costs associated with water transfers – often substantial life-cycle cost components of IBTs. The generally used unit reference value (URV) measure for appraising and ranking water resource projects in South Africa is also rooted in the economic theory of cost-effectiveness. This shows that the current approach is conceptually flawed; it fails to distinguish between water transfers and effectiveness outputs. The determination of the URV equation is expanded and improved. The upgraded appraisal approach, inclusive of the improved URV methodology, is named the Comprehensive Approach. A step-wise demonstration of the Comprehensive Approach is provided. Uncertainty regarding future water transfers and associated variable costs are provided for by stochastic simulation modelling. Decision analysis theory is applied to obtain the appropriate input value of variable costs. It is shown that the Comprehensive Approach can lead to an outcome significantly different from the Incremental Approach. The research provides new insights, placing water resource planning practitioners in a better position to recommend appropriate IBTs in future. These insights can also be transferred to the design of institutional and financial models related to IBTs, as well as the configuration and operation of supply systems including sea-water desalination projects. / AFRIKAANSE OPSOMMING: Suid-Afrika se hidrologiese en geografiese eienskappe, gekoppel aan die ligging van 'n groot deel van sy minerale bates, het gelei tot die ontwikkeling van die komplekse Vaalrivier Voorsieningstelsel, insluitend tussen-bekken oordragskemas waarvan sommige al vir meer as vyf-en-twintig jaar in werking is. Hierdie navorsing vergelyk die werklike wateroordragte van twee sulke oordragskemas met die oorspronklike vooruitskattings tydens die beplanning-stadium. Daar word getoon dat oordragte noemenswaardig minder en ook meer onreëlmatig was as wat voorspel is. Verdere ondersoek toon dat die stand van die stelsel, aan die ontvangskant, die besluitneming rakende die jaar-tot-jaar oordrag beïnvloed het. Historiese evaluerings het 'n “Inkrementele Benadering” (soos hier genoem) gevolg, wat nie voldoende die toekomstige bedryfsomgewing ten opsigte van tussen-bekken oordragte inagneem nie. Ondersoek van ses gevalstudies, vier Suid-Afrikaans, een Sjinees en een Australies, toon dat die Inkrementele Benadering nog algemeen in gebruik is, ten spyte daarvan dat hulpmiddels vir 'n verbeterde benadering beskikbaar is. 'n Nuwe benadering word voorgestel vir die verbetering van vooruitskattings van veranderlike koste wat met wateroordragte geassosieer word – dikwels 'n aansienlike gedeelte van die lewenssiklus-koste van sodanige skemas. Die Eenheidverwysingswaarde (EVW) maatstaf, wat algemeen in Suid-Afrika gebruik word om waterbronprojekte te beoordeel en in rangorde te plaas, word ook geanker in die ekonomiese teorie van koste-effektiwiteit. Daarmee word getoon dat die huidige gebruik van die EVW konsepsioneel gebrekkig is; dit tref nie 'n onderskeid tussen wateroordragte en effektiwiteitsuitsette nie. Die bepaling van die EVW vergelyking is verbreed en verbeter. Die opgegradeerde benadering, met insluiting van die verbeterde EVW metodiek, word die Omvattende Benadering genoem. 'n Stapsgewyse uiteensetting van die Omvattende Benadering word voorsien. Onsekerhede ten opsigte van wateroordragte en geassosieerde veranderlike koste word deur middel van stogastiese modellering aangespreek. Besluitnemingontledingsteorie word ingespan om die toepaslike insetwaarde van die veranderlike koste te bepaal. Daar word getoon dat die Omvattende Benadering tot 'n resultaat kan lei wat aansienlik verskil van wat met die Inkrementele Benadering verkry word. Die navorsing verskaf nuwe insigte wat die waterbronbeplanner in 'n beter posisie sal plaas om gepaste tussen-bekken oordragskemas voor te stel. Hierdie insigte kan ook oorgedra word na die ontwerp van institusionele en finansiële modelle rakende oordragskemas, asook die uitleg en bedryf van voorsieningstelsels, insluitend seewater-ontsoutingsaanlegte.

La digestion anaérobie en voie sèche représente une opportunité de développement de la méthanisation sur le territoire français au vu des gisements agricoles disponibles sur le territoire. Toutefois, l’importance des verrous scientifiques et technologiques de par leur nombre et leur complexité rend cette technologie non mature et peu développée sur le territoire français. Dans ces travaux de thèse, il a été étudié dans un premier axe la mise au point de la détermination de la demande chimique en oxygène (DCO) pour des substrats solides avec un kit commercial rendant celle-ci utilisable sans dilution des déchets et utilisant une faible quantité de réactifs. Cette méthode est un outil de suivi des installations. Un deuxième axe d’étude qui s’est attaché à l’étude de la phase d’acidification, verrou majeur de la méthanisation phase sèche, a démontré l’impact de la conservation et de l’origine des inocula sur leur capacité à gérer une phase d’acidification en présence de déchets facilement hydrolysables. L’inoculum est un paramètre majeur de la méthanisation voie sèche et est pourtant peu étudié. Un troisième axe de cette thèse concerne l’étude des transferts hydriques sur des substrats d’origine agricole par une méthodologie de traçage et de modélisation via le modèle à deux régions d’eau mobile et immobile. L’évolution des transferts hydriques a été étudiée au cours de la digestion anaérobie de fumier bovin en digesteur 60 L montrant une diminution de la perméabilité du massif après le deuxième pic de production de méthane. Par conséquent, tout l’inoculum recirculé passe par les côtés et non au sein du massif solide. Deux fréquences de recirculation ont été testées permettant d’obtenir une amélioration de la production de méthane d’environ 20 %. La caractérisation des transferts hydriques obtenus pour ces deux modalités sont identiques après 32 jours de dégradation anaérobie. Le gain de méthane obtenu se fait donc jusqu’au deuxième pic de production de biogaz par la recirculation. Les bilans hydriques et massiques effectués sur ces digesteurs 60 L démontrent que 36 % de la matière organique sont retrouvés dans le digestat montrant un procédé non optimisé. Le quatrième axe d’étude a été de comprendre et d’étudier la dynamique des populations méthanogènes au sein de digesteurs de méthanisation voie sèche de 60 L selon deux configurations. Des expérimentations modulant l’immersion du massif solide ont conduit à obtenir une amélioration de 13 % de production de méthane pour la condition favorisant l’immersion. Cette augmentation de production de méthane est induite par une plus forte quantité de Methanosarcinaceae. La dynamique des populations méthanogènes a été étudiée dans la phase solide et liquide au cours de la digestion anaérobie montrant un transfert microbien de la phase liquide à solide pour un ordre des bactéries hydrogénotrophes, une hiérarchie de ces « hydrogénotrophes » dans le milieu et un fort développement des « acétotrophes » dans le milieu solide servant de support. Dans un cinquième axe, la mise en oeuvre de la tomographie électrique sur un digesteur de 30 m3 a permis de valider son utilisation pour localiser la phase liquide, les zones de potentiels méthane et les zones dégradées dans un container en fonction des protocoles de remplissage et de vidange du digesteur. Cette méthode est disponible pour localiser les zones mortes et donc pour optimiser le procédé de méthanisation en voie sèche type batch. A travers ces expérimentations menées à différentes échelles et avec différentes problématiques, des méthodologies ont été adaptées pour la compréhension des mécanismes et le suivi du procédé de méthanisation par voie sèche. / The dry anaerobic digestion (AD) process is an opportunity to develop the methanization in France. Agricultural waste is abundant in France. However, many scientific and technical locks are complex and must be solved to develop the dry anaerobic digestion process in France. In this work, the chemical oxygen demand (COD) method was adapted for solid waste no implying waste dilution or a high quantity of reagent. This COD method was available to monitor and manage the dry AD process. The study of acidification phase, a major lock of the dry AD process, showed that the storage condition and the origin of inoculum influence the capacity to manage this phase. The inoculum is a major parameter of the dry AD process. But, the inoculum is few studied.On another part of experiments concerned the water transfers studied on agricultural waste with a tracing method. The modeling of the elution curves to determine the diffusion and the convective transfers was made with a model with two Mobile-Immobile regions. The evolution of water transfers was studied during the AD cycle showing a decrease about the permeability of solid phase after the second peak of methane production. Thus, the inoculum passes on the board of solid phase. Two recirculations were tested allowing to obtain an improvement the methane production about 20 % after the AD cycle. The water transfers of these two recirculations modalities were identical after the AD cycle. The improvement of methane production occurred after the second peak of the methane production. Water and mass balances made showing that 36 % of organic matter was find in the digestat. Consequently, the process was not optimized. Others experiments modulating the immerged part of solid phase showed an improvement of the methane production about 13 % with the increasing of immerged part. This methane improvement was induced by the development of Methanosarcinaceae. The methanogens dynamics were studied in the liquid and solid phases during the AD process showing (i) a population transfer between the liquid phase to the solid phase, (ii) a hierarchy of hydrogenotrophs methanogens in the media, and (iii) a strong development of acetotrophs methanogens in the solid phase. In the final part, the electrical tomography was implemented in a dry AD batch at full scale (30 m3). This method was adapted to localize the liquid phase, the zones of methane potential and the degraded zones according to filling and the emptying protocols. This method can detect the “dead” zones of process in dry AD process.Though, experiments carried out at different scales and with different problematic and several methodologies were adapted to understand the dry AD process. Moreover, the optimization of dry AD process was finding to increase the methane production.