abstract: Water reuse and nutrient recovery are long-standing strategies employed in agricultural systems. This is especially true in dry climates where water is scarce, and soils do not commonly contain the nutrients or organic matter to sustain natural crop growth. Agriculture accounts for approximately 70% of all freshwater withdrawals globally. This essential sector of society therefore plays an important role in ensuring water sources are maintained and that the food system can remain resilient to dwindling water resources. The purpose of this research is to quantify the benefits of organic residuals and reclaimed water use in agriculture in arid environments through the development of a systematic review and case study. Data from the systematic review was extracted to be applied to a case study identifying the viability and benefits of organic residuals on arid agriculture. Results show that the organic residuals investigated do have quantitative benefits to agriculture such as improving soil health, reducing the need for conventional fertilizers, and reducing irrigation needs from freshwater sources. Some studies found reclaimed water sources to be of better quality than local freshwater sources due to environmental factors. Biosolids and manure are the most concentrated of the organic residuals, providing nutrient inputs and enhancing long-term soil health. A conceptual model is presented to demonstrate the quantitative benefits of using a reclaimed water source in Pinal County, Arizona on a hypothetical crop of cotton. A goal of the model is to take implied nutrient inputs from reclaimed water sources and quantify them against standard practice of using irrigated groundwater and conventional fertilizers on agricultural operations. Pinal County is an important case study area where farmers are facing cuts to their water resources amid a prolonged drought in the Colorado River Basin. The model shows that a reclaimed water source would be able to offset all freshwater and conventional fertilizer use, but salinity in reclaimed water sources would force a need for additional irrigation in the form of a large leaching fraction. This review combined with the case study demonstrate the potential for nutrient and water reuse, while highlighting potential barriers to address. / Dissertation/Thesis / Masters Thesis Engineering 2020

A small body of saline rich water rests in the saturated zone between the foredune and the shoreline at certain beaches. This region is beneath the water table and the top of the fresher groundwater, known as the Upper Saline Plume (USP). The USP is significant because density driven flow and chemical fluxes between freshwater, rainwater, and seawater contribute to biogeochemical processes in the subterranean estuary (Duque et al. 2020). The occurrence of the USP has been observed along beaches that have a moderate to gentle slope, fine to medium grain size, and higher wave energy. The goal of this study was to determine if conditions for the presence of USP are consistent throughout different coastal beaches in southeast Florida while mapping the groundwater salinity across the beach. To identify the existence and delimit the boundary interface of the USP in the southeastern coast of Florida, multi–depth samplers were designed, built, and deployed along cross-shore transects at Jupiter and Gulfstream Beaches in Palm Beach County, FL. Groundwater samples were extracted along the transects to measure specific conductance. Although this study did not confirm the existence of the USP in South Florida beaches, an intermediate zone of water that is in-between the specific conductance ranges of relatively freshwater and relatively salty water was identified. Furthermore, the size of this intermediate zone was corresponded with beach slope, showing larger intermediate zones for steeper slopes and vice versa. Finally, temporal changes in the location and morphology of this intermediate zone were also identified in relation to a distinct disturbance event (Hurricane Isaias) which resulted in elevated ocean water levels. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

Because of the endangerment of life of the human beings due to the environmental pollution, a serious study of the pollution of the environment is most vital. Because of increasing surface water pollution there is great hazard of ground water pollution. About half the United States of America derives drinking water from aquifers and much of the projected demand is expected to be met from subsurface sources. Therefore, a study was needed to determine the process of ground water contamination due to nutrients, especially Nitrogen, its degree and Length and Time of Travel and factors inhibiting its flow through soil. The present study was undertaken at the 'Pine Crest Duck Farm' at Sterling, Massachusetts, where the nature of the soil was Gravely Sandy Loam and Three unlined (from the side and bottom) waste stabilization ponds existed and there was a great danger of ground water contamination due to Nitrogen in the vicinity of ponds and further. In the field, observation wells were installed along the redial line and bi-monthly samples of water were taken to monitor the levels of B.O.D., Ammonium, Nitrate and Nitrite Nitrogen. Since the Adsorption of the Nitrogen by the soil is great inhibitor in the movement of the Nitrogen through soil profiles, this study was undertaken to study the adsorptive capacity of the soil in 'Bench Tests' and to test the applicability and validity of various adsorption isotherms of nitrogen in the soil; to develop a dimensional model or prediction equation for the nitrogen in the soil under natural flow conditions by studying the effects of varying concentration and flow rates on the adsorptive capacity of the soil, based on the principles of similitude; to correlate adsorption values in bench and column tests; and to determine the length and time of travel of nitrogen through soil. The soil from the Farm was obtained from a depth of six feet with enough care so that original structure was maintained. Adsorptive capacity of the soil was determined through series of 'Bench Tests' and 'Soil Adsorption Columns' in the laboratory under temperature controlled chambers. From the Bench Tests Adsorption values of the soil at various concentrations of Ammonium, Nitrate and Nitrite Nitrogen were determined and validity and applicability of Adsorption isotherms were confirmed. To study the Adsorption Process under natural flow conditions 'Soil Adsorption Column Tests' were done by using never done before Dimensional Model Analysis of Factors affecting Adsorption and getting dimensionless numbers and further obtaining 'Break Through Curves' at different Concentration and flow rates and Adsorption Values were obtained for Ammonium Nitrogen and Nitrite Nitrogen. Finally, Component and Prediction Equations were obtained for Ammonium Nitrogen and Nitrate Nitrogen. By knowing the Adsorption Values of the soil Length and Time of Travel of Ammonium and Nitrate Nitrogen through soil was calculated at various Concentration Levels. A mathematical Prediction Equation was also obtained between Bench and Column Tests and Length of Time of Travel, t predict the adsorption values under natural flow conditions by just performing less time consuming Bench Tests. It was also found that under equilibrium Bench Test conditions and natural flow conditions, adsorption of Ammonium, Nitrate and Nitrite Nitrogen increased with increasing solution concentration and adsorption of Ammonium Nitrogen was considerably higher than Nitrate and Nitrite Nitrogen. It was further found that for solution concentrations of 20, 40, 60, 80 and 100 mg/l Ammonium Nitrogen and nitrate nitrogen will travel one foot distance in 183 and 115 days; 168 and 111 days; 148 and 98 days; 145 and 81 days; 130 and 98 days; and 127 and 97 days respectively. It was determined that at the present time contamination of shallow water wells does not pose Nitrogen contamination problem and installation of these wells beyond 300 feet radial distance from the waste stabilization ponds was safe.

This study examines the barriers to sustainable water resources management in water vulnerable, yet a mining booming area. The case study is conducted in Omnogovi province of Mongolia in Nov-Dec 2016. This study presents how the Omnogovi province manages its water with increased mining and examines what hinders the province from practicing sustainable water resources management and examines the involvement of residents in the water resources management of Omnogovi province. Qualitative approaches such as semi-structured interviews, participatory observation and literature review were used in this study. This study demonstrates that the water resources management of Omnogovi province is unsustainable in this time period, yet the implementation of IWRM approach has improved the water resources management of the province. The barriers to sustainable water resources management in Omnogovi province are inefficient governance and poor enforcement of law, today. Despite it, data-scarcity and transboundary water issues might become barriers to practice efficient water resources management in the province. The involvement of residents in water resources management of Omnogovi province is deficient, yet the implementation of participatory approach and establishment of RBC might improve the participatory governance. The study shows IWRM can improve the water resources management of a developing country, yet it can be time-consuming, costly and challenging to implement in a country, which is still in socio-economic and political transition.

<p> The Lake Titlow watershed (approximately 35,000 acres) in south-central Minnesota is part of the Minnesota River Basin. The lake is listed in the draft 2010 Clean Water Act Section 303d for nutrient pollution, eutrophication, and biological indicators for impairment of aquatic life and recreational use. Over 90 percent of pre-settlement wetlands are currently drained for agricultural land use. The Lake Titlow watershed is over 80 percent row crops and land use is implicated as a primary cause of impairment in the lake. </p><p> Water samples were collected from the Lake Titlow tributaries McLeod-Sibley Judicial Ditch Number 18 (JD18), Sibley County Ditch Number 18 (CD18), and Ditch 250 (D250) during 2009 and 2010 and were analyzed for total suspended solids (TSS), total phosphorus (TP), and nitrate-nitrite nitrogen (NOx). Investigative methods included continuous recording stream stage and through the use of rating curves, discharge. Runoff, sediment loads, and nutrient loads were then determined from the field data. Four rain gauges collected precipitation each year and were used to assess the impact of precipitation on runoff and loading. Four characteristic precipitation events were selected for each of the calendar years 2009 and 2010 to estimate the loads of sediment and nutrients to the lake and more fully understand the specific roles that land use, hydrologic soil group, slope, and precipitation play with regard to causing sediment and nutrient loading in the lake. </p><p> Results indicate runoff and loads are significant and highly variable by position within the watershed, areas referred to herein as subsheds. The row crop land use, soils characteristics, and precipitation do contribute to overall runoff and loads; however, they do not control subshed variability. Although the low-sloping land surfaces of the watershed should not contribute to overall runoff and loads, results indicate that subtle slope changes in the JD18Lo and CD18Lo subsheds could contribute to the variability of loads seen in these portions of the watershed. </p><p> The location and type of best management practices to implement is debatable because the results of this study indicate that large runoffs and loads could originate within any given subshed during any given rainstorm event. This study was unable to precisely identify the root cause of the variability in subshed runoff and loading. Therefore, it is suggested to look at other factors (e.g., antecedent soil moisture, rainfall intensity, mass wasting, etc.) to explain the subshed variability in the sediment and nutrient loading in future studies of this lakeshed.</p>

<p> This study compared two remote sensing water indices: the Normalized Difference Water Index (NDWI) and the Modified NDWI (MNDWI). Both indices were calculated using publically-available data from the Landsat 8 Operational Land Imager (OLI). The research goal was to determine whether the indices are effective in locating open water and measuring surface soil moisture. To demonstrate the application of water indices, analysis was conducted for freshwater wetlands in the Tualatin River Basin in northwestern Oregon to estimate hydrologic connectivity and hydrological permanence between these wetlands and nearby water bodies. Remote sensing techniques have been used to study wetlands in recent decades; however, scientific studies have rarely addressed hydrologic connectivity and hydrologic permanence, in spite of the documented importance of these properties. Research steps were designed to be straightforward for easy repeatability: 1) locate sample sites, 2) predict wetness with water indices, 3) estimate wetness with soil samples from the field, 4) validate the index predictions against the soil samples from the field, and 5) in the demonstration step, estimate hydrologic connectivity and hydrological permanence. Results indicate that both indices predicted the presence of large, open water features with clarity; that dry conditions were predicted by MNDWI with more subtle differentiation; and that NDWI results seem more sensitive to sites with vegetation. Use of this low-cost method to discover patterns of surface moisture in the landscape could directly improve the ability to manage wetland environments.</p>

<p> Evaluating trends of historical rainfall on a weekly and seasonal basis is needed for optimizing the design and implementation of lawn water conservation strategies like outdoor water restrictions. While &ldquo;day of the week&rdquo; water restrictions are a typical strategy to limit the frequency and duration of urban lawn water use, they may not necessarily result in more conservative behaviors from end-users. Because weekly rainfall and local climate variables are seldom taken into account in water restriction strategies, they are not connected to actual lawn water demand. However, since lawn water demand is directly related to weekly rainfall totals, not to a particular number of watering days per week, water restriction schedules have the potential to unintentionally promote overwatering. This study investigated the weekly patterns of average seasonal rainfall and evapotranspiration in South Florida to determine the typical variability of weekly net irrigation needs and found that typical wet season weekly rainfall often provides a significant amount of water to meet the demand of residential lawns and landscapes. This finding underscores opportunity to reduce supplemental overwatering in residential landscapes if watering guidelines were modified to recognize seasonal average weekly rainfall in this region. </p><p> This study also tested a rainfall-based water conservation strategy to determine if providing residents with information about how local rainfall could promote more effective lawn watering behavior than just water restrictions alone. Experimental households reduced lawn water use by up to 61% compared to the control group by the end of the study. These results demonstrate that the neighborhood &ldquo;rain-watered lawn&rdquo; signs helped experimental study group households become more aware of rainfall as the primary input of water to their lawns. This study also investigated the role that lawn irrigation from self-supplied sources plays in the urban lawn water demand and investigates how the lawn water use and lawn watering behaviors of households that source from self-supply differ from those who source from the public supply.</p>

A Política Nacional de Recursos Hídricos acaba de completar dez anos, período ao longo do qual novos desafios se apresentaram ao gerenciamento dos recursos hídricos à medida que se consolidou a aplicação dos instrumentos de gestão, dentre eles a outorga de direito de uso. Os critérios comumente aplicados na determinação da disponibilidade hídrica para outorga, ao fixarem vazões muito restritivas como quantidade máxima outorgável, se mostraram inadequados à realidade de algumas bacias, que, em pouco tempo, se apresentaram com disponibilidade hídrica crítica ou em vias de criticidade, tendo a somatória das demandas consuntivas alcançado a restrita parcela destinada à outorga estabelecida em legislação. Neste trabalho buscou-se apresentar as inconveniências relacionadas ao uso da vazão mínima de 7 dias com 10 anos de recorrência - Q7,10 - e das vazões de permanência como referência para outorga. Através das leituras de vazões diárias de dois postos fluviométricos da bacia hidrográfica do rio Turvo, em São Paulo, já considerada crítica quanto à disponibilidade hídrica, foi calculada a Q7,10 por ajustes obtidos por quatro distribuições probabilísticas, e também foi construída a curva de permanência de vazões de ambos os postos. Os resultados foram usados no cálculo da vazão outorgável segundo os critérios estaduais baseados em vazão mínima e em vazão de permanência. Discutem-se, então, as imprecisões associadas à Q7,10 e às vazões de permanência em vários aspectos, bem como as inconveniências de se fixar um teto exíguo e universal de outorga a perfis de demandas distintos. Sugere-se, por fim, o abandono destes critérios de outorga e, a partir de algumas experiências de gestão de bacias críticas, apontam-se caminhos alternativos mais adequados, em especial a outorga negociada. / Through these ten years of the Water Resources Brazilian Policy, some difficulties have been presented to the water resources management in so far as the management instruments has becoming solid, mainly to the grant of right for using water resources. A problem of those refers to the low water availability in several water basins, where the total water demands exceed the maximum volume permitted in agreement with the law. This situation occurs by the state criteria which impose low limits for the surface outflows, expressed by minimum flow or flow according to duration curve. This work analyses the constraints when the hydrologic water availability is referred to the Q7,10 (minimum flow with duration of 7 days duration and 10 years of return period), to Q95% (flow equalized or overstated in 95% of the time) or to Q90%. These flows were calculated from the daily records in two hydrological stations located at Turvo River, State of São Paulo, where the consumptive uses are higher than the water availability. The Q7,10 flow was obtained through four probabilistic methods. Also the duration curves were obtained and the results was used to determine the maximum value granted according to state criteria referred to Q7,10, Q95% and Q90% flows. Then, it\'s argued the imprecision related to these three flows in several aspects and the inconvenience of fixing an scanty and universal ceiling to different demands profiles. In conclusion, it\'s suggested the substitution of these criteria and, through some cases of management of critical basins, it\'s pointed alternative methods of grant of right for using water resources.

Bibliography: leaves 61-64. This thesis reviews the sustainability of water resource management in Singapore and adequacy of the water conservation efforts put up by its government, population and industries. The write-up deliberates on the various trans-national water issues faced by the small Republic, interactions within its water sector and with the rest of the economy, management of its water supply and demand, as well as the various problems and challenges confronted by the country. This study is intended to highlight the relative wisdom of reducing water demand over pursuing supply solutions.

<p> This research advances a water infrastructure vulnerability index (WIVI) in order to assess levels of susceptibility within the water sector and its respective infrastructure system(s). WIVI provides an assessment tool that can assist decision makers and policymakers in making better investment decisions supported by a prudent data-driven instrument. The index is dependent upon individual water utility data that are publically available, making it a transparent process that is repeatable and reproducible. Normalization of the data was used to establish baselines, and indicators were developed to represent the different levels of a functional water utility. WIVI provides a quantifiable snapshot of a water utility&rsquo;s past and present state of vulnerability. WIVI is a supportive tool that assists in data-driven decision management, which will determine the direction and allocation of financial infrastructure upgrades pertaining to a water system&rsquo;s need to rehabilitate, replace, or abandon current water system infrastructure.</p>