Дисертації з теми "Groundwater ecosystems"
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Kellermann, Claudia. "Autotrophy in Groundwater Ecosystems." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-104813.
Повний текст джерелаGiusti, Andrea. "Impact of climate changes on groundwater levels and dependent ecosystems." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
Знайти повний текст джерелаIsokangas, E. (Elina). "Quantifying the groundwater dependence of boreal ecosystems using environmental tracers." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526220376.
Повний текст джерелаTiivistelmä Pohjavedestä riippuvat ekosysteemit (GDE) ovat vesi- tai maaekosysteemejä, jotka ovat suoraan tai epäsuorasti riippuvaisia pohjavedestä. Euroopan Unionin ja Suomen lainsäädännön mukaan pohjavesien hallinnassa tulisi ottaa paremmin huomioon GDEt. Tämän työn tavoitteena oli kehittää uusia menetelmiä näiden ekosysteemien luokitteluun ja hallintaan. Luonnollisia merkkiainemenetelmiä soveltaen saatiin uutta tietoa pohjavesi-pintavesi vuorovaikutuksesta ja kehitettiin uusia menetelmiä GDE-luokitteluun järville, soille, puroille ja lähteille. Veden stabiilit isotoopit osoittautuivat tehokkaaksi työkaluksi järvien pohjavesiriippuvuuden määrittämisessä. Iteratiivista isotooppimassatase-menetelmää käytettiin 67 Rokuan järven pohjavesiriippuvuuden selvittämiseen. Veden stabiileilla isotoopeilla pystyttiin myös määrittämään suon pinnan pohjavesiriippuvuus. Viinivaaran harjun viereisen suoalueen tutkimus näytti, että suon pohjavesiriippuvuus voi vaihdella merkittävästi ja pohjavedestä riippuvia alueita löytyy myös nykyisten pohjavesirajojen ulkopuolelta. Lisäksi soilla havaittiin selkeitä pohjavedenpurkupaikkoja lämpökamerakuvauksen avulla. Puroille kehitettiin uusi menetelmä, jolla niiden pohjavesiriippuvuutta voidaan arvioida perustuen pohjaveden määrään puroissa, puroveden lämpötilaominaisuuksiin ja puroveden laatuun. Menetelmää testattiin Viinivaaran ja Rokuan harjuista purkautuville puroille ja sillä havaittiin pohjavesiriippuvuuden vaihtelevan purojen eri osissa. Oulangan lähteitä luokiteltiin eri tyyppeihin hydrologisen ja kemiallisen karakterisoinnin ja tilastollisten menetelmien avulla. Lähteiden altitudin ja δ2H-arvon havaittiin ennustavan lähdeveden kemiallista koostumusta. Tässä tutkimuksessa kehitetyt menetelmät voivat olla hyödyllisiä GDE-luokittelussa, eri ekosysteemien tutkimisessa ja luonnollisten merkkiainemenetelmien soveltamisessa eri ympäristöissä. Kun ekosysteemin pohjavesiriippuvuus tiedetään, voidaan arvioida pohjavedenotosta, ojituksesta ja/tai ilmaston muutoksesta mahdollisesti aiheutuvan pohjavedenpinnan laskun vaikutuksia. Suuressa mittakaavassa, GDE-luokittelumenetelmien tulee olla käytännöllisiä, tehokkaita ja halpoja. Veden stabiilien isotooppien ja muiden merkkiaineiden yhdistetty käyttö vaikuttaa olevan tähän erityisen tehokas työkalu, jolla voidaan ymmärtää ekosysteemien hydrologiaa eri temporaalisissa ja spatiaalisissa mittakaavoissa
Rossi, P. M. (Pekka M. ). "Integrated management of groundwater and dependent ecosystems in a Finnish esker." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526204789.
Повний текст джерелаTiivistelmä Pohjaveteen, hydrologisen kierron avainosaan, kohdistuu kasvavia paineita eri maankäytön muodoista ja ilmastonmuutoksesta. Pohjaveden hallintaan ei kuitenkaan ole kiinnitetty tarvittavaa huomiota. Tässä väitöstyössä yhdistettiin hydrologista ja sosioekonomista tutkimusta Rokuan harjualueella pohjaveden hallintakonseptin päivittämiseksi. Rokuan alueella on useita pohjavedestä riippuvaisia järviä, joiden vedenpinta on kausittain laskenut voimakkaasti. Pintojen lasku on kasvattanut paikallisten huolta järvien tilasta. Harjua ympäröivät metsäojitetut turvemaat, ja ojituksia on syytetty pohjaveden tilan ja sitä kautta myös järvien tilan heikkenemisestä. Työn ensimmäisessä osassa tutkittiin pohjaveden hydrologisia purkautumisprosesseja harjun pohjavesiesiintymästä ojitetulle suoalueelle. Tulokset osoittivat hydraulisen yhteyden akviferin ja turvemaan välillä: pohjavesi pääsi purkautumaan metsäojiin joko suotautumalla tai turpeen kaksoishuokoisuusrakenteiden kautta. Seuraavassa vaiheessa työtä pohjavesimallinnusta käytettiin määrittämään kriittisiä pohjaveden tilaan vaikuttavia tekijöitä pohjavesi-turvemaa-systeemissä. Mallinnustulosten perusteella niin ilmasto kuin maankäyttökin vaikuttavat kumpikin suoraan pohjaveden pinnankorkeuden tilaan. Turvemaiden ojituksilla pohjavesialueella voi olla samoja vaikutuksia pohjaveden pinnankorkeuden tasoihin kuin pohjaveden otolla tai kuivilla kausilla. Turvemaiden ennallistaminen ojia täyttämällä voi osittain palauttaa vedenpinnan tasoja pohjavesialueella. Rokuan harjualueen tapauksessa suuren mittakaavan oja-alueiden ennallistaminen todettiin kuitenkin liian epävarmaksi ja kalliiksi toimenpiteeksi hyötyihin nähden, varsinkin jos kuivien kausien vaikutus suurilla harjualueilla heikkenee tulevaisuudessa sademäärien kasvun myötä. Työn kolmannessa osassa käytettiin monitavoitearviointia eri sidosryhmien osallistamiseen ja oppimiseen pohjavesien hallinnassa. Osallistavasta prosessista saadut tulokset vahvistivat, että menetelmää voidaan käyttää oppimisen edesauttamiseen vaikeissa pohjavesiasioissa sekä yhteistyön muodostamiseen ristiriitaisessa ja monimutkaisessa tapauksessa. Monitavoitearvioinnin prosessi johti keskustelun avaukseen yhtenäisemmän suunnittelun puolesta, joka ottaa huomioon eri sidosryhmien näkökulmat ja tuo ne osaksi keskustelua. Tämä väitöstyö osoitti miten eri pohjavesialueen hallintaan tarvittavat näkökulmat, kuten maankäyttö, ilmasto, ekologiset ja ekonomiset arvot, sekä sidosryhmien mielipiteet voidaan kaikki ottaa huomioon yhdistämällä eri metodeja. Näin tutkimuksella ja informoinnilla vähennetään epäluottamusta eri intressitahojen välillä ja luodaan pohja vakaammalle pohjavesialueiden tulevaisuuden suunnittelulle
Roets, Wietsche. "Groundwater Dependence of Aquatic Ecosystems associated with the Table Mountain Group Aquifer." Thesis, University of the Western Cape, 2008. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3210_1263507816.
Повний текст джерелаResults from this study enables a better understanding of groundwater surface water interactions in the TMG, particularly regarding aquatic ecosystems. It has also highlighted the necessity to do proper impact assessments before proceeding with bulk abstraction from this important aquifer. The results also demonstrated the importance of differentiating between real groundwater and non-groundwater discharge contributions to surface hydrology and where these interface areas are located.
Hernández, del Amo Elena. "Origin and fate of nitrite in model ecosystems: case studies in groundwater and constructed wetlands." Doctoral thesis, Universitat de Girona, 2019. http://hdl.handle.net/10803/668664.
Повний текст джерелаLa contaminació de l’aigua per excés de nitrogen és habitual en el nostre entorn, especialment en llocs impactats per l’agricultura i la ramaderia, zones de descàrrega d’aigües residuals, o com a resultat de l’activitat industrial. L’amoni i el nitrat són els contaminants més freqüents i poden ser eliminats principalment pels microorganismes. Aquesta eliminació la duen a terme diferents microorganismes que habiten en aquests ambients en forma de comunitats, l’estudi de les quals és cabdal per a valorar l’eficiència de l’eliminació del N de l’aigua. En aquesta tesi es desenvolupen mètodes per a fer un estudi acurat d’aquests microorganismes en dos tipus d’ambients altament sensibles a la contaminació, els aiguamolls i l’aigua freàtica.
Sigonyela, Vuyolwethu. "Towards understanding the groundwater dependent ecosystems within the Table Mountain Group Aquifer: a conceptual approach." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_9454_1183462560.
Повний текст джерелаUnderstanding of Groundwater Dependent Ecosystems (GDEs) and their extent within the Table Mountain Group (TMG) aquifer is poor. To understand the dependence to basic ecological and hydrogeological concepts need explanation. The use of current literature aided in identification and classification. From the literature it has come clear that groundwater dependence centers around two issues, water source and water use determination. The use of Geographical Information System (GIS) showed its potential in proof of water sources. Rainfall data and a Digital Elevation Model (DEM) for the Uniondale area have been used to do watershed delineation, which is in line with locating GDEs on a landscape. Thus the conceptual approach should be a broad one that sets a basis for both investigation (scientific research) and institutional arrangements (management).
Lehosmaa, K. (Kaisa). "Anthropogenic impacts and restoration of boreal spring ecosystems." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526218533.
Повний текст джерелаTiivistelmä Ihmistoiminta muuttaa yhä enemmän vesiekosysteemejä. Maankäyttö on johtanut elinympäristöjen häviämiseen, ja siihen liittyvä ravinne- ja haitta-ainekuormitus maa- ja metsätaloudesta sekä kaupunkiympäristöistä on merkittävästi huonontanut veden laatua johtaen maailmanlaajuiseen vesiluonnon monimuotoisuuden heikentymiseen. Vesiekosysteemien tutkimus on keskittynyt pääasiassa järvi- ja jokiympäristöihin, kun ihmistoiminnan vaikutukset pohjavesiriippuvaisiin ekosysteemeihin tunnetaan edelleen huonosti. Samoin kunnostusten merkitys pohjavesiriippuvaisten ekosysteemien tilan parantamiseksi on selvittämättä. Väitöskirjassani tarkastelin kahden keskeisen ihmistoiminnan – metsäojituksen ja pohjaveden laadun heikkenemisen – vaikutuksia lähde-ekosysteemeihin sekä arvioin elinympäristökunnostusten vaikutuksia niiden rakenteeseen ja toimintaan. Sovelsin työssäni rakenteellisia (pohjaeläimet, sammalet, lehtikariketta hajottavat sienet ja pohjavesibakteerit) ja toiminnallisia (eloperäisen aineksen hajoaminen ja perustuotanto) mittareita tuottamaan kattavan käsityksen tutkimuskysymyksiini. Sekä metsäojitukset että pohjaveden laadun heikkeneminen aiheuttavat muutoksia lähteiden rakenteessa ja toiminnassa. Metsäojitukset hidastavat keskeisiä ekosysteemitoimintoja ja johtavat lähdesammallajiston muutokseen ja monimuotoisuuden taantumiseen. Pohjaveden pilaantuminen, jota työssä ilmennettiin kohonneilla nitraatti- ja kloridipitoisuuksilla, heikentää lähdelajiston monimuotoisuutta, muuttaa lajikoostumusta ja johtaa perustuotannon laskuun voimakkaimmin kuormitetuissa lähteissä. Kunnostus parantaa lähde-elinympäristön laatua vähentämällä metsäojien aiheuttamaa pintavesivaikutusta palauttaen pohjavesivaltaisen hydrologisen tilan. Lähdekunnostusten myötä lähdesammaleet runsastuvat ja pohjaeläinyhteisön rakenne palautuu luonnontilaisten lähteiden kaltaiseksi, vaikka kunnostuksista on kulunut vasta muutamia vuosia. Väitöskirjan tulokset osoittavat, että ihmisen toiminta voi aiheuttaa muutoksia lähde-ekosysteemien rakenteessa ja toiminnassa ja lähteiden luontainen palautuminen häiriöstä on hidasta. Lähde-elinympäristöjen kunnostus vaikuttaa lupaavalta suojelutoimenpiteeltä metsäojitusten vaikutusten vähentämisessä, mutta lähteiden säilyttäminen monimuotoisena ja suojelullisesti arvokkaana luontotyyppinä edellyttää pohjavesivarojen hallinnan ja tilan suojelun tehostamista
Mendez-Estrella, Romeo, Jose Romo-Leon, Alejandro Castellanos, Fabiola Gandarilla-Aizpuro, and Kyle Hartfield. "Analyzing Landscape Trends on Agriculture, Introduced Exotic Grasslands and Riparian Ecosystems in Arid Regions of Mexico." MDPI AG, 2016. http://hdl.handle.net/10150/621492.
Повний текст джерелаMaier, Nadine [Verfasser]. "A new method for spatio-temporally explicit predictions of groundwater, surface water and habitat interactions in riparian ecosystems / Nadine Maier." Gießen : Universitätsbibliothek, 2018. http://d-nb.info/1168145619/34.
Повний текст джерелаGosselin, Marie-Pierre. "Aquatic habitat characterization and use in groundwater versus surface runoff influenced streams : brown trout (Salmo trutta) and bullhead (Cottus gobio)." Thesis, Coventry University, 2009. http://curve.coventry.ac.uk/open/items/8d69e5ee-5c54-1d43-2390-e9bea23aad35/1.
Повний текст джерелаMarozava, Sviatlana [Verfasser], Rainer U. [Akademischer Betreuer] Meckenstock, and Wilfried F. M. [Akademischer Betreuer] Röling. "Insights into the microbial physiology of bacteria capable of degrading pollutants in contaminated groundwater ecosystems / Sviatlana Marozava. Gutachter: Rainer U. Meckenstock ; Wilfried F.M. Röling. Betreuer: Rainer U. Meckenstock." München : Universitätsbibliothek der TU München, 2013. http://d-nb.info/1044680474/34.
Повний текст джерелаNeufeld, David A. "Planning to protect groundwater, toward an ecosystem approach." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0011/NQ30636.pdf.
Повний текст джерелаHenderson, James D. "An ecosystem approach to groundwater management in the Gulf Islands." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0010/MQ26766.pdf.
Повний текст джерелаMuschiol, Daniel [Verfasser]. "Meiofauna in a chemosynthetic groundwater ecosystem: Movile Cave, Romania / Daniel Muschiol." Bielefeld : Universitätsbibliothek Bielefeld, 2009. http://d-nb.info/1036110915/34.
Повний текст джерелаAlaibakhsh, Masoomeh. "Digital change detection and separation of anthropogenic and natural impacts on ecohydrological conditions in the Pilbara region, WA." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2017. https://ro.ecu.edu.au/theses/1951.
Повний текст джерелаArufe, Jorge A. "Urbanization, water quality, and aquatic ecosystem condition in the lower Truckee River watershed." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1436471.
Повний текст джерелаau, Stefan@calm wa gov, and Stefan Eberhard. "Ecology and Hydrology of a Threatened Groundwater-Dependent Ecosystem:The Jewel Cave Karst System in Western Australia." Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20051010.141551.
Повний текст джерелаEberhard, Stefan M. "Ecology and hydrology of a threatened groundwater-dependent ecosystem: the Jewel Cave karst system in Western Australia." Thesis, Eberhard, Stefan M. (2004) Ecology and hydrology of a threatened groundwater-dependent ecosystem: the Jewel Cave karst system in Western Australia. PhD thesis, Murdoch University, 2004. https://researchrepository.murdoch.edu.au/id/eprint/61/.
Повний текст джерелаEberhard, Stefan M. "Ecology and hydrology of a threatened groundwater-dependent ecosystem : the Jewel Cave karst system in Western Australia /." Access via Murdoch University Digital Theses Project, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20051010.141551.
Повний текст джерелаEberhard, Stefan. "Ecology and hydrology of a threatened groundwater-dependent ecosystem: the Jewel Cave karst system in Western Australia." Eberhard, Stefan (2004) Ecology and hydrology of a threatened groundwater-dependent ecosystem: the Jewel Cave karst system in Western Australia. PhD thesis, Murdoch University, 2004. http://researchrepository.murdoch.edu.au/61/.
Повний текст джерелаLee, Robert F. "Human health and coastal ecosystem risk assessment of the Massachusetts Military Reservation main base landfill groundwater plume." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/41358.
Повний текст джерелаAdjei, Cornelius Owusu. "Citizen Action, Power Relations and Wetland Management in the Tampa Bay Urban Socio-ecosystem." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/3942.
Повний текст джерелаFranklin, Hannah Mayford. "Understanding Variation in Water Quality using a Riverscape Perspective." Thesis, University of Canterbury. Biological Sciences, 2010. http://hdl.handle.net/10092/5197.
Повний текст джерелаBen, Maamar Sarah. "Biodiversité des eaux souterraines dans un gradient de temps de résidence et d'influence anthropique : approches métagénomique et géochimique couplées." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S108/document.
Повний текст джерелаHard-rock aquifers are heterogeneous geological structure very widespread in Britany that have the property to store groundwater. These aquifers are often made of a weathered zone and a fractured zone. The weathered zone is a rather thin layer close to the surface and is constituted of weathered rocks submerged in groundwater. In this zone, groundwater circulates rapidly from the upper parts of the watershed to the aquifer outlet, thus shows short groundwater residence time (< 20y) and is often polluted by nitrates. The fractured zone is located deeper and is thicker. It is composed of fresh rocks crossed by fractures in which groundwater exclusively flows with a very slow velocity, thus groundwater residence time in this zone is rather long (>40 y). In the fractured zone, groundwater is much more mineralized and often rich in iron, in Britany. The differences of flow velocities in the weathered and the fractured zones are responsible for contrasted chemical conditions in these two zones, but the influence of groundwater flow velocity on the microbial ecosystem in groundwater remains largely unexplored. This work shows hydrologic circulations influence the microbial community structuration in hard-rock aquifer groundwater at regional and local scales. Position of a groundwater along a hydrologic flowpath or a “hydrological loop” directly controls microbial community structure through the control of the successively available electron donors and acceptors. The analyzed microbial communities show a predominance of Betaproteobacteria. In recent groundwater (< 20y) thus particularly in the weathered zone, Betaproteobacteria are mainly Comamonadaceae and Oxalobacteraceae, which are generalists able to do denitrification. In old and isolated groundwater (> 40y) thus particularly in the fractured zone, Betaproteobacteria are mainly Gallionellaceae, which are microaerophilic iron-oxidizer. The predominance of Gallionellaceae in the fractured zone suggests a deep ecosystem based on iron oxidation. However, this process implies a minimal input of oxygen in the deeper part, for instance via mixing with recent oxygenated groundwater. Proportion of Gallionellaceae in the different analyzed groundwater shows a positive correlation with the degree of mixing between old and recent groundwater, up to a limit of 20% of recent groundwater. The temporal microbial community dynamics in a single aquifer, before and during the beginning of recharge, demonstrated in the weathered part very fluctuant chemical conditions and a shifting microbial community that remains always composed of numerous potential denitrifiers. In the fractured part, microbial community is dominated by Gallionellaceae and remains rather stable, despite the punctual but substantial changing of the chemical conditions and degree of mixing (up to 60% of recent groundwater) at the beginning of the recharge. Gallionellaceae seem thus able to resist to important and punctual chemical conditions changings. Groundwater in the deeper part of aquifers, even isolated, remains relatively connected to surface, likely allowing the deep microbial ecosystem to maintain
FERRARINI, ANDREA. "Furnitura multipla di servizi ecosistemici da culture energetiche poliennali." Doctoral thesis, Università Cattolica del Sacro Cuore, 2016. http://hdl.handle.net/10280/10802.
Повний текст джерелаThe 21st century will challenge agriculture to feed and fuel a growing world while conserving the environment. In this thesis an alternative bioenergy land use scenario to the conversion of marginal land has been tested: the bioenergy buffers. Given the environmental issues related to “food-energy-environment” trilemma, the Millennium Ecosystem Assessment framework on ES provides an opportunity to examine the environmental impacts of this new bioenergy land use scenario. In this thesis I aimed to determine to what extent do the perennial bioenergy crops affect the delivery of multiple ES when cultivated as bioenergy buffers. To reach this aim, I combined a systematic revision of literature on ES provided by perennial bioenergy crops with a field experiment on bioenergy buffers. Applying an impact scoring methodology to the effects on ES extracted from literature, I showed that, cultivating perennial bioenergy crops along field margins of former croplands offer a great opportunity to sustain the provision of multiple ES. The cultivation of perennial bioenergy crops on field margins can improve climate, biodiversity and water regulation services, sustain soil health and provide biomass for energetic purposes. On the contrary, grassland conversion showed a net negative impact on multiple ES provision. Nevertheless, I found two main shortcomings related to bioenergy buffers establishment and management. First, several site-specific factors along field margins must be taken into account, because they can affect crop establishment and buffers long-term productivity. Second, regarding to biomass supply chain, a limited working space for the farm machinery operations has been recognized as the main disadvantages of bioenergy buffers compared to large-scale bioenergy plantations. This spatial logistics constraint may inevitably increase harvest and collection operation times and fossil fuel consumption. Conducting a field experiment with bioenergy buffers in a nitrate-enriched shallow groundwater, I showed that miscanthus and willow buffers are able to efficiently intercept and remove from groundwater the incoming NO3-N as much as buffer strips with spontaneous species. Yet, due to their deep rooting systems, bioenergy buffers promote significant plant-microbial linkages along the soil profile. At deeper soil layers, a higher fine root biomass led perennial bioenergy crops to outperform patches of adventitious vegetation in terms of biological N removal from soil and belowground GHG mitigation potential. The results on biomass production and N removal via harvesting further confirmed that the cultivation of perennial bioenergy crops along watercourses is an effective win-win strategy: biomass production and protection of the environment. In conclusion, the revealed potential of perennial bioenergy crops on multiple ES provision implies that their cultivation as perennial landscape elements in strategic locations within landscape is a promising option to promote the ecological sustainable intensification of agroecosystems.
Kellermann, Claudia [Verfasser]. "Autotrophy in groundwater ecosystems / vorgelegt von Claudia Sabine Kellermann." 2008. http://d-nb.info/99651869X/34.
Повний текст джерелаFurlong, Michelle Ann. "Bacterial communities in natural ecosystems : groundwater, soil, earthworm casts and burrows." 2000. http://purl.galileo.usg.edu/uga%5Fetd/furlong%5Fmichelle%5Fa%5F200008%5Fphd.
Повний текст джерелаGaskill, Teresa G. Restom. "Hydrology of forest ecosystems in the Honouliuli Preserve implications for groundwater recharge and watershed restoration /." Thesis, 2004. http://proquest.umi.com/pqdweb?index=0&did=813798261&SrchMode=1&sid=4&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1235092745&clientId=23440.
Повний текст джерелаDekker, Peter Andrew. "Evaluating the Potential for Low Impact Development to Mitigate Impacts of Urbanization on Groundwater Dependent Ecosystems using MIKE SHE." Thesis, 2012. http://hdl.handle.net/10214/5286.
Повний текст джерела(5930639), Carolyn L. Gleason. "LIFE IN THE RAIN SHADOW: UNDERSTANDING SOURCES OF RECHARGE, GROUNDWATER FLOW, AND THEIR EFFECTS ON GROUNDWATER DEPENDENT ECOSYSTEMS IN THE PANAMINT RANGE, DEATH VALLEY, CALIFORNIA, USA." Thesis, 2019.
Знайти повний текст джерелаDespite its location in the rain shadow of the southern Sierra Nevada, the Panamint Range within Death Valley National Park, CA hosts a complex aquifer system that supports numerous springs. These springs, in turn, support unique groundwater-dependent ecological communities. Spring emergences range in elevation from 2434 m above sea level (within the mountain block) to 77 m below sea level (in the adjacent basins). Waters were collected from representative Panamint Range springs and analyzed for environmental isotopes and geochemical tracers to address the following questions: 1) What is the primary source of recharge for the springs? How much recharge occurs on the Panamint Range? 2) What groundwater flowpaths and geologic units support springflow generation? and 3) What are the residence times of the springs? The stable isotopic composition (δ18O and δ2H) of spring water and precipitation indicate that localized high-elevation snowmelt is the dominant source of recharge to these perennial springs, though recharge from rainfall is not wholly insignificant. Geochemical evolution was evaluated using principle component analysis to compare the concentrations of all major spring cations and anions in a multidimensional space and group them according to dominant geochemical signatures. These resulting geochemical groups are controlled primarily by topography. The Noonday Dolomite and other carbonate units in the range are identified as the water-bearing units in the mountain block based on the 87Sr/86Sr of spring waters and rock samples. These units also offer higher hydraulic conductivities than other formations and are chemically similar. Radiocarbon- and 3H derived residence times of these spring waters range from modern to approximately 1840 years, with the shortest residence times at higher altitudes and Hanaupah Canyon and increasing residence times with decreasing altitude. This residence time-altitude relationship is likewise likely topography-driven though there are significant disparities in mountain block storage between the various canyons of the range resulting in variable residence times between drainages. Lower Warm Springs A and B, however, are the exceptions to this trend as they emerge at lower altitudes (750m above sea level) and are likely driven by the transport of groundwater to the surface along faults which increases both the temperature and groundwater residence times of waters from these springs. Benthic macroinvertebrates and benthic and planktonic microbes were also sampled for each spring studied. BMI and microbial community structure in the Panamint Range is likewise topography-controlled with more tolerant communities at lower elevations (within more chemically evolved waters) and less tolerant species in the unevolved waters at higher elevations.
"Desert Playa Wetlands: Ecological Controls of their Functioning and Responses to Climate Change." Doctoral diss., 2016. http://hdl.handle.net/2286/R.I.40695.
Повний текст джерелаDissertation/Thesis
Doctoral Dissertation Biology 2016
Wilson, Kevin Patrick. "An in-situ temperature manipulation of a shallow groundwater ecosystem : analysing consequences of global warming /." 2008. http://proquest.umi.com/pqdlink?did=1670249881&sid=14&Fmt=2&clientId=12520&RQT=309&VName=PQD.
Повний текст джерелаFan, Yen-Tzu, and 范晏慈. "Importance of groundwater activities in downstream urban river ecosystem: A case study in Jingmei River, Taiwan." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/3jp677.
Повний текст джерела國立臺灣大學
生物環境系統工程學研究所
101
In river ecosystems, groundwater (GW) and surface water (SW) exchange is an important natural process for maintaining vertical hydrological connectivity, material fluxes and ecosystem health. The vertical GW-SW exchange could increase the habitat complexity and maintain the stability of the water physiochemistry and hydrology in the rivers. Spatial variation of GW-SW exchange pattern could represent a key factor for characterizing aquatic biodiversity and faunal community structure. Also, GW activities exhibit seasonality resulting in the dynamic patterns of river ecosystems. In the northern Taiwan, high GW level in Taipei basin during March to July and low level during September to October are influenced by the seasonal variation of precipitation and evaporation. Such temporal variation could thus be important for enhance the diversity of river habitat and aquatic biota. However, Taiwan as other countries in the world, it has been rapid population increase and urban development since the recent decades, most downstream rivers have been channelized to avoid flood and increase urban land use. River beds of some channelized rivers are commonly covered with impermeable concrete materials. This man-made structure causes the blockage of GW-SW exchange. Also, urbanization usually results in the dominance of invasive species in aquatic ecosystems and this can endanger the native communities. In this study, we first carried out small-scale field manipulative experiment on river bed of Jingmei River and compared the areas of “pit” (depression structure directly caused by GW) and “non-pit” (areas not directly affected by GW activities) to investigate the influences such as water and habitat quality, faunal composition, and the trophic basis associated with GW activities in an urban river ecosystem. Our study site located at the downstream Jingmei River in the Taipei basin where sufficient GW layer lies underground. Taipei basin is one of the densely urbanized areas and most rivers in the basin are channelized with impervious river bed to reduce flood impacts. However, sufficient GW layer widely extends underneath the Taipei basin especially at Jingmei district. The downstream Jingmei River is channelized at both river banks but the river bed remains unmodified so that GW-SW exchange could be maintained. In addition, the dominant fish in downstream Jingmei River is dominated by tilapia (Cichlidae: Oreochromis niloticus) which has a special breeding behavior that male fish make bowl-shaped craters to attract the female for spawning. As we found many bowl-shaped pits on the river bedduring our preliminary survey, we conducted the fish exclusion experiment to confirm whether the pits were formed from GW activity or fish breeding behavior in downstream Jingmei River. Then, flow visualization experiment was undertaken at pits and control locations to determine the direction of the GW activity in Jingmei River. We further compared the water chemistry between pits and non-pits to determine the differences of water quality influenced by GW activities. In addition, we investigated the invertebrate biodiversity and community structure at pits and non-pits to evaluate the biological response to GW activity. Finally, we used stable carbon and nitrogen isotope analysis in conjunction with gut content analysis to study the GW influence on the trophic basis in downstream Jingmei River. As the bowl-shaped pits were formed under both the fish exclusion and control areas, our results confirmed that GW-SW exchange did occur in downstream Jingmei River. Flow visualization experiment results revealed that the sinking rate at pits was significantly lower than at non-pits (1-way ANOVA, p < 0.05). This indicated that the GW activities at pits was via GW upwelling. In addition, conductivity, TDS, ORP, pH, and water temperature were significantly different between pits and non-pits (1-way ANOVA, p < 0.05) suggesting that GW activities strongly affected the water quality in this urban river. Moreover, our study showed that invertebrate density was higher in subsurface sediment at pits although the taxon richness and biodiversity of invertebrates were not particularly higher at pits than non-pits. This indicated that GW influenced pits by providing more suitable habitats to support high faunal density. Our findings also showed that fishes utilized high proportion (~ 40%) of pit resources in Jingmei River. Since food resources of pits were characterized by lower C/N ratio, consumers tended to use the pit resources and the dependence of pit resources was related to ontogenetic development of tilapia. Our study confirmed that GW activities could effectively enhance the habitat quality through increasing the habitat diversity in the hydromorphologically homogeneous urban river. Hence, our results could provide important information for the urban river restoration in the future.
Peterson, Tim J. "Multiple hydrological steady states and resilience." 2009. http://repository.unimelb.edu.au/10187/8540.
Повний текст джерелаAguilar, Perez Raquel. "Arid groundwater dependent ecosystem response to salinization processes in a coastal aquifer: deriving vegetation indicators of the aquifer condition." Master's thesis, 2013. http://hdl.handle.net/10400.1/6823.
Повний текст джерелаManter a qualidade das águas subterrâneas constitui uma preocupação crucial devido aos crescentes níveis de contaminação dos lençois freáticos a nível mundial. Este tópico é particularmente importante nas zonas áridas, uma vez que as precipitações, que representam uma fonte importante de abastecimento de água doce subterrânea para a sociedade e para os ecosistemas, são escassas nas zonas áridas. Neste estudo utilizamos uma abordagem ecohidrológica para obter indicadores de esforço da condição dos aquíferos, com base na monitorização da vegetação freatófita, um caso particular de Ecossistemas Dependentes de Águas Subterrâneas (GDEs: Groundwater dependent ecosystems). Como exemplo de vegetação freatófita das zonas áridas analisou-se o Z.lotus que é um arbusto de folha caduca do Norte de África e Sudeste de Espanha. Este estudo teve como objetivo relacionar a estado biológico do Z. lotus com o estado das águas subterrâneas para explorar a viabilidade de utilização de indicadores de vegetação para informar sobre os níveis de salinização das águas subterrâneas dos aquíferos costeiros. Para isso: 1) avaliaram-se os níveis de salinização do aquífero do Parque do Cabo de Gata-Níjar Natural, através de amostragem de poços; 2) determinou-se o gradiente de distância de água salobra com recurso a uma sondagem elétrica vertical (SEV), a condição fisiológica do Z. lotus através da análise química foliar e os índices espectrais de vegetação (NDVI e NDWI) ao longo de um gradiente de salinidade. Os resultados mostraram que através da análise química das folhas de Z. lotus foi possivel determinar o nível freático, a distância ao mar, a salinidade e a água doce disponíveis para os GDEs. No entanto, os níveis de salinidade não se refletiram claramente no verdor da vegetação (NDVI) e no teor de água da vegetação (NDWI), provavelmente por Z. lotus apresentar tolerância ao sal dentro da gama de salinidade presente no aquífero. Em conclusão, recomendamos como bom indicador da salinização das águas subterrâneas a concentração de íons nas folhas. Em contrapartida, sugerimos que os índices espectrais de vegetação são bons indicadores da saúde da vegetação, mas não são bons para a quantificação da salinização das águas subterráneas. Z. lotus é provavelmente o único EDAS terrestre nas zonas áridas da Europa e o seu estudo é fundamental para a gestão e conservação deste ecossistema.
Universidade do Algarve, Faculdade de Ciências e Tecnologia
Knüppe, Kathrin. "Comparative case study analysis of adaptive groundwater governance and management regimes: Exploring ecosystem services in South Africa, Spain and Germany." Doctoral thesis, 2012. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-2012102210424.
Повний текст джерелаCrowell, Morgan. "An ecosystem service approach to inform reactive nitrogen management in the lower Yakima River Basin, Washington." Thesis, 2012. http://hdl.handle.net/1957/35853.
Повний текст джерелаGraduation date: 2013
"Deep Percolation in Arid Piedmont Watersheds and Its Sensitivity to Ecosystem Change." Doctoral diss., 2017. http://hdl.handle.net/2286/R.I.48444.
Повний текст джерелаDissertation/Thesis
Doctoral Dissertation Geological Sciences 2017
Medina, Israel. "Characterization of a Karst Coastal Ecosystem in the Mexican Caribbean: Assessing the Influence of Coastal Hydrodynamics and Submerged Groundwater Discharges on Seagrass." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9060.
Повний текст джерелаKim, John H. "Trading Carbon and Water Through Vegetation Shifts." Diss., 2011. http://hdl.handle.net/10161/5703.
Повний текст джерелаIn this dissertation, I explored the effects of vegetation type on ecosystem services, focusing on services with significant potential to mitigate global environmental challenges: carbon sequestration and groundwater recharge. I analyzed >600 estimates of groundwater recharge to obtain the first global combined analysis of groundwater recharge and vegetation type. Using a regression model, I found that vegetation was the second best predictor of recharge after precipitation. Recharge rates were lowest under forests, intermediate in grasslands, and highest under croplands. The differences between vegetation types were higher in more humid climates and sandy soils but proportionately, the differences between vegetation types were higher in more arid climates and clayey soils. My extensive field estimates of recharge under paired vegetation types in central Argentina and southwestern United States provided a more direct test of the relationships between vegetation and recharge. The field data confirmed the strong influences of vegetation and its interactions with abiotic factors on recharge observed in the synthesis. The results indicate that vegetation shifts have a proportionately larger potential to affect recharge in more arid climates and clayey soils.
At the same study systems, I compared my field estimates of recharge to organic carbon stocks (in biomass, litter and soil) under the different vegetation types to evaluate tradeoffs between carbon sequestration and groundwater recharge as affected by vegetation shifts. To determine net values of vegetation shifts, I combined the changes in carbon and water with reported economic values of the ecosystem services. Based on physiological tradeoffs between photosynthesis and transpiration in plants, I hypothesized that vegetation promoting carbon storage would reduce recharge and vice versa. Changes in water and carbon services were inversely proportional, with rain-fed cultivation increasing groundwater recharge but decreasing carbon storage compared to the grasslands they replaced whereas woody encroachment did the opposite. In contrast, cultivated plots irrigated with ground water decreased both ecosystem services. Higher precipitation and clay content both exacerbated changes in carbon storage with grassland conversions, whereas higher precipitation accentuated, but higher clay content diminished, those in recharge. Regardless of the nature of vegetation shift, most of the net values of grassland conversions were negative, with the shifts representing increasing costs in the following order: woody encroachment, rain-fed cultivation and irrigated cultivation. Values of changes in carbon were greater in magnitude than those of recharge, indicating that establishment of carbon markets may drive land-use changes in grasslands over water markets.
Lastly, I examined the effects of changes in subsurface hydrology resulting from grassland conversion to croplands on soil inorganic carbon stocks in the same U.S. study system. I observed significantly lower inorganic carbon stocks under both rain-fed and irrigated croplands compared to the grasslands they replaced. The losses were visible to past 6 m depth in the soil profile and were uncharacteristically rapid for the carbon pool that is considered to be relatively inert. Based on the negative relationship between the inorganic carbon stocks and recharge rates and higher estimated exports of bicarbonates in recharge under croplands, I concluded that increased recharge with cultivation resulted in dissolution and leaching of grassland soil carbonates. Ecosystem services and their relationships to biotic and abiotic factors quantified here will further our understanding of the tradeoffs and interactions between the two services through vegetation shifts.
Dissertation
Ramusiya, Fhedzisani. "Hydrological Characterisation of the Shingwedzi and Mphongolo River Basins in Kruger National Park, South Africa." Diss., 2010. http://hdl.handle.net/11602/1057.
Повний текст джерелаLamberts, Jill S. "Nutrient release and cycling in the soils of a continental lodgepole pine (Pinus contorta Doug.) ecosystem, Bootleg Mountain, B.C." Thesis, 2005. http://hdl.handle.net/1828/46.
Повний текст джерела