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Delineating wetlands using geographic information system and remote sensing technologiesVilleneuve, Julie 12 April 2006 (has links)
During the last century wetlands have considerably decreased. The principal cause
is urbanization, especially in large urban regions such as the Houston area. In order
to protect the remaining wetlands, they have to be monitored carefully. However
monitoring wetland is a difficult and time-demanding task because it has to be done
repetitively on large areas to be effective. This study was conducted to determine if
Geographical Information System (GIS) and remote sensing technologies would allow
accurate monitoring of wetland as a less time-consuming method. With this idea,
a suitability model was developed to delineate wetlands in the Houston area. This
model combined GIS and remote sensing technologies. The data used for this study
were as high spatial resolution as possible and were generally easy to obtain. This
suitability model consisted of four submodels: hydrology, soil, vegetation and multi-
attribute. Each submodel generated a Wetland Suitability Index (WSI). Those WSI
were summed to obtain a general WSI. The suitability model was calibrated using
half of the study area. During calibration, the general model was evaluated as well as
each individual index. Generally, the model showed a lack of sensitivity to changes.
However, the model was slightly modified to improve the delineation of upland wet-
lands by increasing the weight of the soil submodel. This model was validated using
the second half of the study area. The validation results improved a bit compared to
the calibration results; however they remained weak. It was demonstrated that the
model does not favor riverine wetlands over upland wetlands, nor large size wetlands. The model ground truth data were evaluated and were suffciently proven to be up to
date. Those results indicated that the weakness of the model must come from inac-
curacy in the input data. Therefore, the study showed that while existing computing
capacity supports remote delineation, spatial accuracy is still insuffcient to perform
correct wetland delineation using remote sensing and GIS technologies.
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Hydroperiod of wetlands and reproduction in wood frogs (rana sylvatica) and spotted salamanders (ambystoma maculatum) /Kolozsvary, Mary Beth, January 2003 (has links) (PDF)
Thesis (Ph. D.) in Ecology and Environmental Science--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 88-96).
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Crayfish (Procambarus spp.) response to hydrologic restoration of the Florida Everglades /Hendrix, Albert Noble. January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 133-144).
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A review of freshwater wetland conservation in Hong Kong: policy and practiceLee, Kai-tung., 李啟同. January 2006 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
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The medieval exploitation of the peat moors of the Somerset LevelsMusgrove, David James January 2000 (has links)
No description available.
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The effects of Common Carp (Cyprinus carpio L.) on water quality, algae and submerged vegetation in Delta Marsh, ManitobaHertam, Susan 21 September 2010 (has links)
Common Carp, (Cyprinus carpio), have long been associated with the degradation of wetlands worldwide. Through their feeding activities they resuspend sediments leading to reductions in the abundance and diversity of submerged macrophytes, and the alteration of water chemistry which can lead to the phytoplankton-dominated state. This study took in Delta Marsh, a freshwater coastal wetland of Lake Manitoba, in Manitoba, Canada. It was the second part of a four-year study in which baseline data were collected in 2001 from ten ponds (1-13 ha) with varying degrees of connectivity to the main marsh and carp-accessibility. I continued to monitor a subset of the control and altered ponds two and three years following their alteration (2003 and 2004); I included new ponds, including one large open bay (20.3 ha). The overall four-year study has shown that the presence of carp is at least partially responsible for the turbid, phytoplankton-dominated state that exists in Delta Marsh, and that carp abundance is an important factor. Ponds previously isolated then exposed to carp activity, particularly in the spring when they were gathered at high densities, shifted to the turbid, phytoplankton-dominated state with few macrophytes, and the removal of carp from ponds led to the clear-water state, though not necessarily an abundance of macrophytes. Due to the complexity of natural ecosystems, the effects of carp were not as predictable as smaller-scale studies would suggest. In my study, water quality, submerged vegetation biomass and algal growth varied both temporally and spatially in carp-accessible and carp-free ponds. Nutrient deficiency among periphyton assemblages was hypothesized to be alleviated by the presence of carp. Using nutrient diffusing substrata, I found that nutrient deficiencies varied from year to year among carp-free and carp-accessible ponds. In 2003 the hypothesis was supported, however, in 2004 two of the carp-free ponds exhibited no-nutrient limitations to periphyton assemblages while N and P co-limitation became prevalent in one carp-accessible pond. Parameters over which there was no control, such as the spatial and temporal distribution of carp, their density within a pond, water depth and unquantified top-down effects, including zooplankton grazing, may have contributed to the variability of the results.
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The effects of Common Carp (Cyprinus carpio L.) on water quality, algae and submerged vegetation in Delta Marsh, ManitobaHertam, Susan 21 September 2010 (has links)
Common Carp, (Cyprinus carpio), have long been associated with the degradation of wetlands worldwide. Through their feeding activities they resuspend sediments leading to reductions in the abundance and diversity of submerged macrophytes, and the alteration of water chemistry which can lead to the phytoplankton-dominated state. This study took in Delta Marsh, a freshwater coastal wetland of Lake Manitoba, in Manitoba, Canada. It was the second part of a four-year study in which baseline data were collected in 2001 from ten ponds (1-13 ha) with varying degrees of connectivity to the main marsh and carp-accessibility. I continued to monitor a subset of the control and altered ponds two and three years following their alteration (2003 and 2004); I included new ponds, including one large open bay (20.3 ha). The overall four-year study has shown that the presence of carp is at least partially responsible for the turbid, phytoplankton-dominated state that exists in Delta Marsh, and that carp abundance is an important factor. Ponds previously isolated then exposed to carp activity, particularly in the spring when they were gathered at high densities, shifted to the turbid, phytoplankton-dominated state with few macrophytes, and the removal of carp from ponds led to the clear-water state, though not necessarily an abundance of macrophytes. Due to the complexity of natural ecosystems, the effects of carp were not as predictable as smaller-scale studies would suggest. In my study, water quality, submerged vegetation biomass and algal growth varied both temporally and spatially in carp-accessible and carp-free ponds. Nutrient deficiency among periphyton assemblages was hypothesized to be alleviated by the presence of carp. Using nutrient diffusing substrata, I found that nutrient deficiencies varied from year to year among carp-free and carp-accessible ponds. In 2003 the hypothesis was supported, however, in 2004 two of the carp-free ponds exhibited no-nutrient limitations to periphyton assemblages while N and P co-limitation became prevalent in one carp-accessible pond. Parameters over which there was no control, such as the spatial and temporal distribution of carp, their density within a pond, water depth and unquantified top-down effects, including zooplankton grazing, may have contributed to the variability of the results.
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Implications of shallow groundwater and surface water connections for nitrogen movement in typical Boreal Plain landscapesVallarino, Amy 05 September 2014 (has links)
This thesis examines both surface water and shallow groundwater connections in boreal watersheds at two study sites in the Athabasca Oil Sands Region using conventional hydrological techniques as well as stable water isotope techniques. Increased emissions due to oil sands development are expected to contribute significantly to acidifying airborne emissions. Specifically, nitrogen is forecasted to be deposited on the surrounding area within approximately 100 km of operations. The purpose of the research is to provide background information for predicting how individual terrain units such as fens, bogs, and uplands will respond to increased nitrogen loads, and to assess whether or not these units will act as sources or sinks of nitrogen under higher nitrogen deposition.
Two study sites situated within 100 km of Fort McMurray, Alberta were instrumented with a total of 30 nested piezometers, 26 water table wells, 4 micro-meteorological stations, and two gauging stations (weirs) at outflow points. Monitoring occurred during the open water season of 2011 and 2012. This study estimates evaporation through a simplified energy balance, documents hydraulic conductivity of shallow aquifers, utilizes stable isotopes of water to assist in mapping seasonal flow patterns, and calculates a vertical water balance for the sites. Bogs and fens were hydrologically connected, as bogs fed fens laterally at shallow depths within the acrotelm during wet years. Upland terrain units were found to have more variable connections. In spring, upland runoff recharged the wetlands at both sites. At JPH groundwater flowed towards the fen, whereas in ML limited connections were observed between the uplands and the fen. Also, no connections were seen to indicate that the wetlands recharged the uplands. A conceptual model is developed that emphasizes the role of connectivity in the boreal landscape. The main implication for nitrogen cycling is that it is difficult to quantify one landscape as a source or sink for additional nitrogen as its role may vary depending on seasonality and temporal scales. Further work is needed to identify if nitrogen loadings will have adverse affects on geochemistry of water at the sites. / Graduate / 0366 / amyvallarino@gmail.com
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Habitat classification with reference to flooding and salinity, to assist with the vegetation of a saline artificial wetland /Hunter, Sally Ann. January 1998 (has links) (PDF)
Thesis (M. Env. Sc.)--University of Adelaide, Mawson Graduate Centre for Environmental Studies, 1999. / Includes bibliographical references (leaves 104-110).
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Mangrove wetlands in Bangladesh /Begum, Fatema. January 1998 (has links) (PDF)
Thesis (M. Env. Sc.)--University of Adelaide, Mawson Graduate Centre for Environmental Studies, 1998. / Includes bibliographical references (leaves 65-71).
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