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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Evaluation of Environmental Impacts of Short Rotation Coppice with Regard to the Amount and Quality of Groundwater Recharge

Schmidt-Walter, Paul 23 September 2019 (has links)
No description available.
182

Short-Term Water Use Dynamics in Drainage Lysimeters

Dlamini, Musa V. 01 May 2003 (has links)
Turfgrass water use (seasonal turfET) and crop coefficients were determined and a mathematical soil-water balance model for non-weighing drainage lysimeters, which simulates the occurrence (timing and amount) of drainage, was developed. Pairs of non-weighing drainage lysimeters were used to determine crop coefficients for turfgrass in four locations in the state of Utah: Logan Golf and Country Club, Murray Golf Course, Brigham Young University (Spanish Fork) Experiment Farm, and Sunbrook Golf Course (St. George). Daily weather data including air temperature, relative humidity, average wind travel, total solar radiation, precipitation, and average soil temperature were collected with an electronic weather station at each site. Daily precipitation was measured in three sites throughout the season: Murray, Spanish Fork, and Sunbrook. At Logan Golf and Country Club, precipitation was measured to November 10,2002. Water use (averages of two lysimeters) during the growing season varied from 684 to 732 mm for three years (2000- 2002) for the mid-April through late-October observation period at Logan Golf Course; 699 mm for May through October at Murray; 469 mm at Spanish Fork; and 896 mm for late-February through early November at Sunbrook, for 2002 growing season. Calculated seasonal Etr using the 82 Kimberly Penman equation with a 1 00-miles-per-day wind travel limit varied from 1166 to 1229 mm at Logan Golf and Country Club, 1067 mm at Murray, 839 mm at Spanish Fork, and 1574 mm at Sunbrook. Seasonal Etr calculated using the PM ASCE std Etr equation was greater than the 82 Kimberly Peru11an . Seasonal Eto calculated using the FAO#56 Eto equation was less than both the 82 Kimberly Penman and the PM ASCE std Etr equations. Calculated crop coefficients (as a ratio of measured crop water use and calculated potential evapotranspiration) based on alfalfa reference evapotranspiration with the 1982 Kimberly-Penman equation averaged 0.58 for the three years at Logan. Seasonal averages varied from 0.57 to 0.60. Seasonal crop coefficients (2002) were 0.57 for Logan, Spanish Fork, and Sunbrook, and 0.65 for Murray. Short-period crop coefficients also varied within a given season. Short-term crop coefficients derived from a time of wetting and drainage experiment averaged 0.55 at Logan, 0.56 at Murray, 0.60 at Spanish Fork, and 0.56 at Sunbrook.
183

Characterization of domestic wastewater discharge and its impact on material flows in urban Hue, Vietnam / ベトナム国フエ都市部における生活排水の排出特性及び物質フローへの影響

Tran, Nguyen Quynh Anh 23 September 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第20039号 / 地環博第155号 / 新制||地環||31(附属図書館) / 33135 / 京都大学大学院地球環境学舎環境マネジメント専攻 / (主査)教授 藤井 滋穂, 准教授 田中 周平, 准教授 大下 和徹 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM
184

Furrow Irrigation Strategies for Peanut Production in the Mid-Southern USA

Leininger, Stephen 10 August 2018 (has links)
Accurately delivering and precisely timing sprinkler irrigation improves peanut yield and profitability, but there are no data on how to achieve this in the mid-southern USA where furrow-irrigation dominates. This research was conducted to determine if soil water potential could be manipulated through land preparation method, irrigation delivery, and irrigation scheduling. The effects of land preparation method (flat vs bed), furrow-irrigation delivery (every vs every-other furrow), and irrigation scheduling [Food and Agriculture Organization and drainage paper 56 (FAO-56), - 50 kPa, -75 kPa, and -100 kPa] on peanut yield, net returns above irrigation costs, and irrigation water use efficiency were investigated near Stoneville, MS on a Bosket very fine sandy loam. Our data indicate that regardless of land preparation method, peanut yield, net returns above irrigation costs, and irrigation water use efficiency are most often optimized in the mid-southern USA by irrigating every other furrow at a threshold of -50 kPa.
185

Development and Its Impact on the Water Balance of an Urban Watershed

Chenevey, Benjamin 15 October 2013 (has links)
No description available.
186

Landward moisture fluxes for the Northern Hemisphere

Omolayo, Aribilola Samuel. January 1980 (has links)
Thesis: M.S., Massachusetts Institute of Technology, Department of Meteorology, 1980 / Bibliography: leaves 39-41. / by Aribilola Samuel Omolayo. / M.S. / M.S. Massachusetts Institute of Technology, Department of Meteorology
187

Vattenförbrukningen på Storsudret : en modellering av ett begränsat områdes vattenförbrukning och dess årsvariationer / The water consumption at Storsudret : a modeling of a definied area's water consumption and its annual variations

Söderberg, Rebecka, Hermansson, Linnea January 2018 (has links)
Syftet med detta arbetet är att skapa en förståelse kring vattenförbrukningen på Storsudret, som är beläget på Gotland, samt hur den varierar över året. Detta för att kunna planera för en framtida hållbar vattenförsörjning i ett område där vattenbrist periodvis hotar och klimatförändringar förväntas ge betydande konsekvenser. Genom framtagning av en modell som beräknar vattenförbrukning för fyra kategorier har den totala årsförbrukningen på Storsudret sammanställts. Vattenförbrukningen kan användas som riktlinje vid dimensionering av grundvattendammar som planeras i området för att stärka lagringen av grundvatten. Modellen är skapad i programmet Excel och kategorierna består av hushåll, djurhållning, bevattning och service. Modellen innehåller ett antal parametrar som anges för de olika kategorierna samt vilka månader som antas tillhöra låg-, medel- och högsäsong. Vattenförbrukningen för respektive kategori räknas ut i kubikmeter per månad och år och redovisas i en sammanställning över året. Utöver vattenförbrukningen i dagsläget har två scenarier tagits fram och studerats där Scenario 1 är baserat på strålningsdrivningsscenariot RCP 8.5, framtaget av FN:s Klimatpanel för att bilda en uppfattning om framtidens klimat vid fortsatt höga utsläpp, samt Scenario 2 som är baserat på hur mycket åkermark som bevattnas.  Sammanställningen av vattenförbrukningen för Storsudret framgick till ett värde på 407 000 kubikmeter per år och visade på en kraftig variation över året där vattenförbrukningen var som högst under sommarmånaderna. För vattenförbrukningen i dagsläget antogs att tio procent av Storsudrets åkerareal bevattnas vilket gav det överlägset största bidraget till vattenförbrukningen. I Scenario 2.1 beräknades årsförbrukningen utan bevattning vilken resulterade i 187 000 kubikmeter. Scenario 2.2 innebar full bevattning och resulterade i en mycket stor total årsförbrukning på 2,4 miljoner kubikmeter vatten. Scenario 1 resulterade i en vattenförbrukning på 611 000 kubikmeter per år och 199 000 kubikmeter exklusive bevattning. Klimatförändringarnas förväntade effekter på vattenförbrukningen bör beaktas vid planering för en framtida hållbar vattenförsörjning. Vid dimensionering av grundvattendammar är det rimligt att bortse från bevattning förutsatt att bevattningen även fortsättningsvis sker genom bevattningsdammar och att kapacitet för detta finns. / The purpose of this work is to create a better knowledge of the water consumption at Storsudret, which is located on the island of Gotland, and how it varies over the year. This to be able to plan for a future sustainable water consumption in an area where water shortage periodically is threatening and climate changes are expected to have significant consequences. By creating a model which calculates the water consumption for four categories, the total annual consumption at Storsudret has been compiled. The total water consumption can be used as a guideline when dimensioning the groundwater dams that are planned in the area to reinforce the magazines of groundwater. The model is created in the program Excel and the categories consists of household, animal husbandry, irrigation and service. The model contains a number of parameters which is entered for the different categories and which months that belongs to off-season, mean season and peak season. The water consumption for each category is calculated in cubic meters per month and year and is presented in a compilation over the year. In addition to the water consumption at present, two scenarios have been developed and studied where Scenario 1 is based on the Representative Concentration Pathway RCP 8.5, developed by the Intergovermental Panel on Climate Change to form an opinion about the future climate if continuing a high rise of emission, and Scenario 2 is based on how much of the cropland is being irrigated.  The compilation of the water consumption at Storsudret resulted in a value of 407 000 cubic meters a year och showed a strong variation over the year, where the water consumption was at its highest during the summer months. When calculating the water consumption at present, an irrigation of ten percent of the cropland was assumed which represented the biggest addition to the water consumption. In Scenario 2.1 the total water consumption for a year was calculated without any irrigation and resulted in 187 000 cubic meters. In Scenario 2.2 the irrigation was at full-scale (when calculating the water consumption for a year) and resulted in a very large total annual consumption at 2,4 million cubic meters of water. Scenario 1 resulted in a water consumption of 611 00 cubic meters a year and 199 000 cubic meters excluding the irrigation. The climate change’s expected impacts on the water consumption should be taken into account when planning for a future sustainable water supply. It is reasonable to ignore the irrigation when dimensioning the groundwater dams hence most of the irrigation is done with the help of irrigation dams.
188

Grundvattenbalans i Kustnära Områden

Hildingsson, Hugo January 2018 (has links)
Vatten är en livsviktig resurs för allt liv. I Sverige kommer hälften av allt dricksvatten från grundvatten. I kustnära områden begränsas grundvattentillgången av omgivningens lagringsförmåga och begränsad tillrinningsyta och det leder till att tillgången på vatten ett växande problem. Det är därför viktigt att förstå alla parametrar som påverkar grundvattnet, både för nutida och framtida brukare. Förändringen av grundvatten i geologiskt blandad miljö är svårt att kartlägga på grund av lagerföljder, materialens heterogenitet, låg kinematisk porositet och okunskap om strömningen mellan olika lager. Grundvattennivåerna skiftar dessutom med klimatet, både över året och över längre tid. Även människans påverkan är av stor betydelse. Rapportens syfte är att se hur dessa parametrar påverkar grundvattenytan i förhållande till varandra. För att undersöka dessa parametrar har tre olika geografiska, kustnära områden jämförts: Stor, Blidö, och Insjön, Rådmansö, i Norrtälje kommun samt Klintemåla i Oskarshamns kommun. För att sätta vattenanvändningen i ett sammanhang har uppgifterna relaterats till vattenexploateringsindexet (WEI). Uppgifter har hämtats från SGU, SMHI och Lantmäteriets arkiv. I två fall har kompletterande fältundersökningar genomförts. Informationen har bearbetats i Excel och programmet GWBal. I dessa områden råder lokal akut eller total vattenbrist under vissa sommarmånader. Förekomsten av vatten är en fråga om lokal tillgång och en generellt god situation i Sverige döljer stora regionala och lokala obalanser. Vad fritidsboende gör spelar större roll än permanentboende då det är under sommarsäsongen problemen är störst. Mindre reservoarer är känsligare när parametrar för klimat, vattenförbrukning och kemisk sammansättning förändras. De klimattendenser som nu uppvisas leder till konklusionen att grundvattentillgången i områdena under den kritiska perioden kommer att minska. / Water is a vital resource for all human life. Half of all drinking water in Sweden comes from groundwater and in some coastal areas, the access to water is a growing problem. It is therefore crucial to properly understand all parameters that affect the access to water, both for present and future users. The change in groundwater level in geologically varied environments is hard to get a complete picture of. Stratification, heterogeneity of soil and rock, low kinematic porosity and flow between the layers are partially unknown parameters and therefore highly uncertain. Groundwater levels also change with the climate, both over the year and over longer period of time. The impact of humans is of great importance. The objective is to see how these parameters effects groundwater level in relation to each other. To analyze these factors, three different geographic areas in Sweden will be compared: Stor, Blidö, and Insjön, Rådmansö, in Norrtälje kommun and Klintemåla in Oskarshamns kommun. To put the water use and potential stress in context, the results will be related to the Water Exploitation Index (WEI). Data was obtained from the archives of SGU, SMHI and Lantmäteriet. In two cases, the information was supplemented with field investigation. The information was processed in Excel and the program GWBal. Overall, the local shortage of water in these areas is urgent during some summer months. The water supply is a local resource and the generally good situation in Sweden conceals major regional and local imbalances. The part time residents have a much greater impact since the problem is at its peak during summer. Changes in the climate, withdrawal of water and chemical composition have greater impact on small reservoirs then on big ones. With today’s trend in climate, the conclusion is that the availability of groundwater in the areas will decrease.
189

Hydrological and chloride transport processes in a small catchment of the Norrström Basin : a MIKE SHE modelling approach

Liu, Zhuhuan, Zhou, Chen January 2019 (has links)
Water is ubiquitous on our planet and constitutes a vital part of ecosystems. It supports the life of all beings on the earth while simultaneously evokes water-related issues such as water shortage, water contamination. As UN advocates, a globally shared blueprint for available clean water is depicted in Sustainable Development Goals (SDGs). However, there still exists a gap between current water management situations and our sustainable goals Modelling based on Hydro-Meteorological Data provides a way to understand regional hydrological processes and monitor environmental chemistry changes, especially for anthropogenic pollution. Furthermore, hydrological models make it possible to predict changes in water quantity and quality, under the context of climate change. The study area of this project is located in the Kringlan catchment, Norrström basins, occupying an area of 54.5 km2. The local discharges merge into Rastälven river and flow to the east, eventually discharging into the Baltic Sea. This project builds up a water balance model based on the meteorological data in the time frame from 2011 to 2012. The water balance model is calibrated to accurately simulate realistic hydrological components interactions, during each process, various parameters have been tested and adjusted to improve model robustness. Meanwhile, the project tries to strike a balance between the complexity of the model and amount of time it takes to run the model. The calibrated model is also validated to ensure model performance using statistical analysis. Additionally, a particle tracking model for the saturated zone is developed on the basis of the water balance model. Chloride is chosen as the trace element due to its feature of unreactive in ecological systems. The model results could also provide a value to groundwater age estimation. Suggested by previous researches targeting the area, leakage from vegetation and forest soil in this catchment have contributed to imbalances in local Cl- budgets. An internal source of chloride from soil leaching is specified in the model at the same time with an external source from stream discharge. The coupled modelling through the application of MIKE SHE software and calibration process help us to understand dynamic processes of hydrological modelling and chloride particle transport in the Kringlan catchment. A future improvement to consider is extending the current model boundary to a larger area and introducing more reference data. It is also possible to establish a fully integrated solute transport model to investigate Chloride transport in the catchment. / Vatten ersätter en viktig del av ekosystemet men det framkallar vattenrelaterade problem som vattenbrist och vattenförorening samtidigt. Emellertid finns det fortfarande ett gap mellan nuvarande vattenhanteringssituationer och våra hållbara mål. Modellering baserad på meteorologiska data erbjuder en möjlighet att förstå regionala hydrologiska processer och övervaka förändringar av miljömässiga kemikalier, särskilt för antropogena föroreningar. Dessutom finns det en hög potential för att förutse förändringar i vattenmängd och kvalitet med hydrologiska modeller, i samband med klimatförändringar. Studieområdet ligger i Kringlans upptagningsområde som ett av Norrström basins, med en yta på 54,5 km2. De lokala utsläppen sammanfogas i Rastälven och strömmar österut, så småningom mynnar i Östersjön. Detta projekt bygger upp en vattenbalansmodell baserad på meteorologiska data inom tidsramen från 2011 till 2012. Vattenbalansmodellen är kalibrerad för att exakt simulera realistiska hydrologiska komponentinteraktioner. För att förbättra modellens robusthet har olika parametrar testats och anpassats under varje process. Samtidigt försöker projektet att hitta en balans mellan modellens komplexitet och hur lång tid det tar att driva modellen. En partikelspårningsmodell för den mättade zonen har utvecklats med utgångspunkt i vattenbalansmodellen. Klorid används som spårämne eftersom det är inert i ekologiska system. Modellsresultaten kan också ge ett värde för grundvattenberäkningen. Tidigare undersökningar inriktade på området föreslår att läckage från vegetation och skogsmark i detta avrinningsområde har bidragit till obalanser i lokala Cl- budgetar. Med hjälp av MIKE SHE modellen har vi undersökt dynamisk process för hydrologisk modellering och kloridpartikelspårning i Kringlan avrinningsområde. Vad som kan gör i framtiden är att förlänga den nuvarande modellgränsen till ett större område med mer referensdata. Det är också möjligt att upprätta en fullständigt integrerad lösningsmodell för att undersöka kloridtransporter i ett avrinningsområde.
190

Land Use Effects On Energy And Water Balance-developing A Land Use Adapted Drought Index

Cheng, Chi Han 01 January 2012 (has links)
Climate change is expected to increase the frequency, intensity and duration of droughts in all parts of the United States (US). Snow packs are disappearing earlier in the spring and summer, with reduced stream-flow. Lower reservoir levels, higher temperatures, and greater precipitation variability have been observed. Drought events in the US have threatened drinking water supplies for communities in Maryland and Chesapeake Bay as observed in 2001 through September 2002; Lake Mead in Las Vegas in 2000 through 2004; Peace River and Lake Okeechobee in South Florida in 2006; and Lake Lanier in Atlanta, Georgia in 2007. ENSO influences the climate of Florida; where El Niño years tend to be cooler and wetter, while La Niña years tend to be warmer and drier than normal in the fall through the spring, with the strongest effect in the winter. Both prolonged heavy rainfall and drought potentially have impacts on land uses and many aspects of Florida's economy and quality of life. Drought indices could integrate various hydrological and meteorological parameters and quantify climate anomalies in terms of intensity, duration, and spatial extent, thus making it easier to communicate information to diverse users. Hence, understanding local ENSO patterns on regional scales and developing a new land use drought index in Florida are critical in agriculture and water resources planning and managements. Current drought indices have limitations and drawbacks such as calculation using climate data from meteorological stations, which are point measurements. In addition, weather stations are scarce in remote areas and are not uniformly distributed. Currently used drought indices like the iv PDSI and the Standardized Precipitation Index (SPI) could not fully demonstrate the land use effects. Other limitations include no single index that addresses universal drought impact. Hence, there is a renewed interest to develop a new “Regional Land Use Drought Index (RLDI) that could be applied for various land use areas and serve for short term water resources planning. In this study, the first and second research topics investigated water and energy budgets on the specific and important land use areas (urban, forest, agriculture and lake) in the State of Florida by using the North American Regional Reanalysis (NARR) reanalysis data. NARR data were used to understand how drought events, EI Niño, La Niña, and seasonal and inter-annual variations in climatic variables affect the hydrologic and energy cycle over different land use areas. The results showed that the NARR data could provide valuable, independent analysis of the water and energy budgets for various land uses in Florida. Finally, the high resolution land use (32km×32km) adapted drought indices were developed based on the NARR data from 1979 to 2002. The new regional land use drought indices were developed from normalized Bowen ratio and the results showed that they could reflect not only the level of severity in drought events resulting from land use effects, but also La Niña driven drought impacts.

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