Storing almost a third of the global soil carbon pool, wetlands are an essential component of the carbon cycle, and carbon-rich peat soil accumulates when carbon input through primary productivity exceeds output through decomposition. However, woody shrub encroachment in herbaceous wetlands can alter soil carbon processes, potentially diminishing stored carbon. To examine the effects of shrub encroachment on soil carbon, I compared soil carbon input through litterfall and fine root production, output through decomposition, and below-canopy microclimate conditions between Carolina willow shrub (Salix caroliniana) and herbaceous sawgrass (Cladium jamaicense) in the Blue Cypress Marsh Conservation Area (BCMCA), FL. To assess the level of production and its response to water level, I compared aboveground green biomass by measuring normalized difference vegetation index (NDVI) and photosynthetic stress by measuring photochemical reflectance index (PRI) between sawgrass and willow. I collected willow litterfall using litter traps and measured sawgrass and willow fine root production with fine root ingrowth bags. Litter decomposition was measured with decomposition bags deployed using a reciprocal litter placement design at BCMCA and incubated in a greenhouse to examine the effects of char and water level on decomposition. Above and belowground microclimate conditions were measured using sensors installed within sawgrass and willow canopies. Despite experiencing more photosynthetic stress, willow produced more green biomass than sawgrass. However, willow produced fewer fine roots than sawgrass and these roots were deeper within the soil. Willow litter decomposed faster even though sawgrass decomposition increased under drier conditions. Compared to the sawgrass canopy, the willow canopy had greater light availability, lower evaporative demand plus warmer and drier soils; however, litter decomposition did not differ between the canopies. These results suggest that willow encroachment can reduce the amount and alter the distribution of carbon within an herbaceous wetland, likely resulting in a net loss of soil carbon. Although willow encroachment may increase aboveground biomass carbon stocks, these stocks will likely be offset by a loss of soil carbon due to reduced fine root production and increased decomposition. Therefore, the transition from herbaceous wetland to shrub wetland will likely result in a loss of stored soil carbon. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

With a global population about 7 billion people and their continued growth are pressuring global natural resources, in freshwater matter this pressure is altering both the river flows; timing season of water flows; and spatial patterns in order to meet human demands both in urban as rural areas. However, water stress in urban areas are increasing and expectations by 2050 are grim with a global urban development by 70 percent moreover urbanization rate expected by 2030 in Latin America is 80 percent, thus the water concerns because of high average water consumption 220 lpd, and water leakage by 29 percent in the third largest city of Ecuador Cuenca have motivated to perform this analysis. The analysis is based on a metabolic perspective in order to determine anomalies in the urban water cycle at household level for then apply one of the tools of stormwater management in short term such as harvesting rainwater to find how feasible can be this system both individually as communally in Cuenca urban area based on criteria of rainfall, roof surface, roof material, water average consumption, and costs; in order to generate social, economic, and environmental benefits. Moreover, give recommendations and strategies in mid and long term to get an Integrated Urban Water Management (IUWM) model that allow ensuring the enough natural resources, environmental health, and economic sustainability for current and future demands. The main problems in the urban water cycle are in a outdated urban water management because of water leakage in the delivery network and unsuitable water pricing as well as bad consumers habits; these are affecting economically the water enterprise; nonetheless these problems are not putting in risk freshwater resources, and infrastructure capacity to meet future demands but the implementation of harvesting rainwater systems both individual as community can allow water savings by 18 percent at household level, and by 11 percent in whole water production process at city level. Moreover, the implementation can generate 750.000 job positions both direct as indirect. Finally, the risk of floods can be mitigated due to, roughly 2.88 million m3 of runoff rainwater a year are not released on rivers. To conclude, economic losses are avoiding that this money can be used to improve and maintain the current infrastructures, and development socio-technical projects in order to get a more suitable water metabolism. In other hand, encourage a harvesting culture at household level is a good strategy in short term but its feasibility is related directly to five drivers of which four can be handled such as roof surface area, roof material, domestic water consumption, and costs; in order to get most efficient systems. Finally, there are more tools and strategies to get sustainable goals in short mid and long term through an Integrated Urban Water Management model, in order to urban dwellers can move from simply consumers to a status of suppliers and managers of resources.

Water scarcity is a common phenomenon in sub-Saharan Africa, and Kenya is one of the hardest-hit countries. Estimates show that up to 41% of the population lacks access to clean and safe drinking water, and ten million people collect their daily drinking water from polluted sources. The situation is particularly critical in Machakos County, which has the country's lowest level of developed water resources, such as piped infrastructure. This study aims to understand which characteristics affect water users' participation in collaborative environmental management and whether resource users' involvement in managing water resources affects their perceptions of the performance of water services. The study shows a low level of participation among domestic water users in Machakos County. The low level of participation is mainly due to the lack of social interaction between the resource users and the governing institutions. At the same time, the study cannot link the outcome of water management to the level of participation among resource users.

Intermittent water supply is a major challenge in informal settlements (slums) in Nairobi, Kenya. Smart water man- agement is an emerging technology that uses sensory net- works for continuous monitoring of water infrastructure to detect anomalies and inform effective distribution of wa- ter resources. This thesis investigates how visualization of data collected from the water network can support the lo- cal water utility in the Nairobi slums in improving water distribution, including maintenance and development. An explorative qualitative study, including interviews with util- ity staff members and field observations informed the devel- opment of three conceptual prototypes to propose how the collected data could be incorporated in the water utility’s practices. The design of the prototypes lead to a discussion on how smart water management can be adapted to the specific challenges of the context. The thesis concludes by suggesting that a successful implementation of smart water management, besides supporting efforts directly related to the slum areas, must also address the problems of inefficient and inequitable water allocation concerning the whole city of Nairobi. ­­ / Oregelbunden vattenförsörjning är en stor utmaning i informella bosättningar (slumområden), i Nairobi, Kenya. Smart water management är ett ny tekniskt område som använder sensornätverk för kontinuerlig övervakning av vatteninfrastrukturer för att upptäcka avvikelser, som t.ex. läckage, och informera effektiv distribution av vattenresurser. Denna studie undersöker hur visualisering av data som samlats från vattennätet kan stödja det lokala vattenbolaget i Nairobi i arbetet med att förbättra vattendistributionen, inklusive underhåll och utbyggnad. En explorativ kvalitativ förstudie baserad på intervjuer med anställda på vattenbolaget och fältobservationer användes som underlag för en designprocess av interaktiva datavisualiseringar. I designprocessen skapades tre konceptuella prototyper som exemplifierar hur den insamlade datan skulle kunna inkorporeras i vattenbolagets praxis. Utformningen av prototyperna ledde till en diskussion om hur smart water management kan anpassas till de särskilda förutsättningarna i Nairobis informella bosättningar.  En lyckad implementation av smart water management måste, förutom att stödja de insatser direkt relaterade till de informella bosättningarna, också adressera problematiken gällande ineffektiv och ojämlik fördelningen av vattenresurser i hela staden Nairobi.

Shale gas has emerged as a potential resource to transform the global energy market. Nevertheless, gas extraction from tight shale formations is only possible after horizontal drilling and hydraulic fracturing, which generally demand large amounts of water. Part of the ejected fracturing fluid returns to the surface as flowback water, containing a variety of pollutants. Thus, water reuse and water recycling technologies have received further interest for enhancing overall shale gas process efficiency and sustainability. Thereby, the objectives of this thesis are: - Develop mathematical models to treat flowback and produced water at various salinities and flow rates, decreasing the high environmental impact due to the freshwater withdrawal and wastewater generated during shale gas production at minimum cost. - Develop mathematical programming models for planning shale gas water management through the first stage of the well's life to promote the reuse of flowback water by optimizing simultaneously all operations belonging several wellpads. Within the first objective, we developed medium size generalized disjunctive-programming (GDP) models reformulated as mixed integer non-linear programming problems (MINLPs). First, we focused on flowback water pretreatment and later, in wastewater desalination treatment. Particularly, an emergent desalination technology, Membrane Distillation, has been studied. All mathematical models have been implemented using GAMS® software. First, we introduce a new optimization model for wastewater from shale gas production including a superstructure with several water pretreatment alternatives. The mathematical model is formulated via GDP to minimize the total annualized cost. Hence, the superstructure developed allows identifying the optimal pretreatment sequence with minimum cost, according to inlet water composition and wastewater desired destination (i.e., water reuse as fracking fluid or desalination in thermal or membrane techonologies). As each destination requires specific composition constraints, three case studies illustrate the applicability of the proposed approach. Additionally, four distinct flowback water compositions are evaluated for the different target conditions. The results highlight the ability of the developed model for the cost-effective water pretreatment system synthesis, by reaching the required water compositions for each specified destination. Regarding desalination technologies, a rigorous optimization model with energy recovery for the synthesis of multistage direct contact membrane distillation (DCMD) system has been developed. The mathematical model is focused on maximizing the total amount of water recovered. The outflow brine is fixed close to salt saturation conditions (300 g·kg-1) approaching zero liquid discharge (ZLD). A sensitivity analysis is performed to evaluate the system’s behavior under different uncertainty sources such as the heat source availability and inlet salinity conditions. The results emphasize the applicability of this promising technology, especially with low steam cost or waste heat, and reveal variable costs and system configurations depending on inlet conditions. Within the second objective, large-scale multi-period water management problems, and collaborative water management models have been studied. Thus, to address water planning decisions in shale gas operations, in a first stage a new non-convex MINLP optimization model is presented that explicitly takes into account the effect of high concentration of total dissolved solids (TDS) and its temporal variations in the impaired water. The model comprises different water management strategies: direct reuse, treatment or send to Class II disposal wells. The objective is to maximize the “sustainability profit” to find a compromise solution among the three pillars of sustainability: economic, environmental and social criteria. The solution determines freshwater consumption, flowback destination, the fracturing schedule, fracturing fluid composition and the number of tanks leased at each time period. Because of the rigorous determination of TDS in all water streams, the model is a nonconvex MINLP model that is tackled in two steps: first, an MILP model is solved on the basis of McCormick relaxations for the bilinear terms; next, the binary variables that determine the fracturing schedule are fixed, and a smaller MINLP is solved. Finally, several case studies based on Marcellus Shale Play are optimized to illustrate the effectiveness of the proposed formulation. Later, a simplified version of the shale gas water management model developed in the previous work has been used to study possible cooperative strategies among companies. This model allows increasing benefits and reduces costs and environmental impacts of water management in shale gas production. If different companies are working in the same shale zone and their shale pads are relatively close (under 50 km), they might adopt a cooperative strategy, which can offer economic and environmental advantages. The objective is to compute a distribution of whatever quantifiable unit among the stakeholders to achieve a stable agreement on cooperation among them. To allocate the cost, profit and/or environmental impact among stakeholders, the Core and Shapley value are applied. Finally, the impact of cooperation among companies is shown by two examples involving three and eight players, respectively. The results show that adopting cooperative strategies in shale water management, companies are allowed to improve their benefits and to enhance the sustainability of their operations. The results obtained in this thesis should help to make cost-effective and environmentally-friendly water management decisions in the eventual development of shale gas wells.

Water shortages resulting from increased demand or reduced supply may be addressed, in part, by redirecting recycled water for irrigation, industrial reuse, groundwater recharge, and as effluent discharge returned to streams. Recycled water is an essential component of integrated water management and broader adoption of recycled water will increase water conservation in water-stressed coastal communities. This study examined spatial patterns of recycled water use in Florida in 2009 and 2015 to detect gaps in distribution, quantify temporal change, and identify potential areas for expansion. Databases of recycled water products and distribution centers for Florida in 2009 and 2015 were developed by combining the 2008 and 2012 Clean Water Needs Survey databases with Florida’s 2009 and 2015 Reuse Inventory databases, respectively. Florida increased recycled water production from 674.85 mgd in 2009 to 738.15 mgd in 2015, an increase of 63.30 mgd. The increase was primarily allocated to use in public access areas, groundwater recharge, and industrial reuse, all within the South Florida Water Management District (WMD). In particular, Miami was identified in 2009 as an area of opportunity for recycled water development, and by 2015 it had increased production and reduced the production gap. Overall, South Florida WMD had the largest increase in production of 44.38 mgd (69%), while Southwest Florida WMD decreased production of recycled water by 1.68 mgd, or 3%. Overall increase in use of recycled water may be related to higher demand due to increased population coupled with public programs and policy changes that promote recycled water use at both the municipal and individual level.

For the water management the forecast of precipitation is an important input variable for hydrologic models. With a accurate forecast, suitable protection measures, for example dam-predischarges can be initiated on time. However, the precipitation forecast is difficult, because it has a large spatial and temporal variability. This can be seen by the large differences of predicted precipitation height of different forecasts. With a validation of predictions of the COSMO-EU-Model and the radar-based analysis data of RADOLAN a possible optimum warning time shall be found. In addition, different continous verification methods are applied. Additionally, a possible spatial influence of the orography and different general weather situations where analysed. A total of 57 days, with more than 50mm precipitationheight in 24 h were validated in the years from 2006 to 2014. The data refer to five different catchment areas of Saxony which are managed by the State Reservoir Administration of Saxony (LTV). It has been found that at 62% of the validated forecasts not enough precipitation was predicted. The closer in time forecast and precipitation event are, the better is the forecast skill. An optimal earlier forecast time cannot be found under the use of the currently available precipitation forecasts. / Für dieWasserwirtschaft ist die Niederschlagsvorhersage eine wichtige Eingangsvariable für hydrologische Modelle. Mit einer guten Vorhersage können die entsprechenden Schutzmaßnahmen wie z.B. Talsperrenvorentlastungen rechtzeitig eingeleitet werden. Jedoch ist die Vorhersage des Niederschlags schwierig, da er eine große räumliche und zeitliche Variabilität hat. Diese zeigt sich auch in der Variabilität der Niederschlagshöhe zu unterschiedlichen Vorhersageterminen. Mit einer Validierung zwischen Vorhersagen des COSMO-EU-Modells und den radargestützen Analysedaten von RADOLAN für Regenmengen in verschiedenen Talsperreneinzugsgebiet Sachsens soll untersucht werden, ob es einen optimalen Warnzeitpunkt gibt, der gekennzeichnet ist durch eine möglichst frühe gebietsgenaue Niederschlagsprognose, so dass für das Durchführen wasserwirtschaflicher Maßnahmen ausreichend Zeit verbleibt. Um dies einschätzen zu können, werden hier verschiedene kontinuierliche Gütemaße angewandt. Auch ein möglicher räumlicher Einfluss durch die Orographie und der Einfluss verschiedener Großwetterlagen wurde dabei untersucht. Es wurden insgesamt 57 Tage, an welchen mehr als 50 mm Niederschlag in 24 h fiel, in den Jahren 2006 bis 2014 validiert. Die Daten beziehen sich auf fünf Wassereinzugsgebiete Sachsens, die durch die Landestalsperrenverwaltung des Freistaates Sachsen (LTV) bewirtschaftet werden. Dabei hat sich herausgestellt, dass bei 62 % der untersuchten Vorhersagen zu wenig Niederschlag vorhergesagt wurde. Die unterschiedlichen Gütemaße zeigen das erwartete Verhalten, dass je näher der Vorhersagetermin am Ereignis liegt, desto besser das Gütemaß und somit auch die Vorhersage ist. Ein optimaler früherer Vorhersagezeitpunkt kann unter Verwendung der derzeit verfügbaren Niederschlagsprognosen nicht gefunden werden.

This thesis explores two examples of water management in the highland Peruvian villages, San Pedro de Llancha and San Antonio de Chinchina. One example is of cooperation and union between the two communities. The other is of conflict between the same two villages just 40 years prior. I examine ethnographic and ethnohistorical data from both the collaborative period and the conflictive period of these two communities’ relations over water. The data suggest that, while the outcomes of these two periods were drastically different, the processes through which these communities came into relation with one another were quite similar. Their communal union or fragmentation depended on subtle differences in their positional relations to a common resource, water, others who needed the resource, and external entities who had authority over that resource. The result is two neighboring sister communities who flow in to and out of each other’s communal orbit according to circumstance and practice, rather than permanent, abstract village identity.

System models have been used to improve water management and environmental decision making. In spite of the many existing mathematical models and tools that attempt to improve environmental decision making, few efforts have been made to identify how scarce resources (e.g., water, budget) can be more efficiently allocated to improve the environmental and ecological performance of different ecosystems (e.g., wetland habitat). This dissertation presents a set of management tools to improve the environmental and ecological performance. These tools are described in three studies. First, a simple optimization model is developed to help regulators and watershed managers determine cost-effective best management practices (BMPs) to reduce phosphorus load at the Echo Reservoir Watershed, Utah. The model minimizes the costs of BMP implementation to achieve a specified phosphorus load reduction target. Second, a novel approach is developed to quantify wetland habitat performance. This performance metric is embedded in a new optimization model to recommend water allocations and invasive vegetation control in wetlands. Model recommendations are subject to constraints such as water availability, spatial connectivity of wetland, hydraulic infrastructure capacities, vegetation growth and responses to management, plus financial and time resources available to allocate water and invasive vegetation control. Third, an agent-based model is developed to simulate the spread of the invasive Phragmites australis (common reed), one of the most successful invasive plant species in wetlands. Results of the agent-based model are embedded into an optimization model (developed in the second study) to recommend invasive vegetation control actions. The second and third studies were applied at the Bear River Migratory Bird Refuge, which is the largest wetland complex on the Great Salt Lake, Utah. These three studies provide a set of decision-support tools that recommend: (1) BMPs to reduce phosphorus loading in a watershed, (2) management strategies to improve wetland bird habitat, and (3) control strategies to minimize invasive Phragmites spread. Together, these models provide important insights and recommendations for managers to make informed decisions to manage excess nutrients in water bodies as well as to improve wetland management.

Tourism is one of the leading industries, in terms of international trading between countries. In addition to receipts received at destinations, international tourism has also generated US$211 billion in exports through international passenger transport services. The study is conducted in Isfahan, a city in center of Iran. The city is unique in its cultural heritage and archeology. It is one of Iran's oldest cities at more than 1,500 years of age. An important cultural and commercial center, Isfahan is Iran's third largest metropolitan area. Isfahan experiences an arid climate, like the rest of the Iranian plateau with low rainfall. Isfahan has a high capacity to attract international tourists to provide a better understanding of Iran’s history, culture, and natural environment to the world. Zayandeh Rud which means “life-giving River” is the largest Iranian plateau and the most important surface water in Isfahan. It starts from Zagros Mountains and ends in the Gavkhouni Swamp, a seasonal salt lake in the southeast of Isfahan. The catchment area has been affected by two drought periods within the last 15 years. Decreasing surface and groundwater availability has been accompanied by an increase in water withdrawal for irrigation, domestic uses, industry, and water transfers to neighboring provinces. This has led to severe ecological and social consequences. This study identifies the potentials of Isfahan in attracting international tourists and also evaluate the water crisis that the city faces. The research is based on qualitative method. The primary data is gathered through face to face and phone interviews and questionnaires. The results show some finding solutions to water crisis in Isfahan and some suggestions for improving tourism industry in the city.