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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.
171

Assessment of Wetland Water Quality and Plant Species Composition across the Rural, Peri-Urban, and Urban Gradient

Steinman, Alexis January 2017 (has links)
The Prairie Pothole Region, specifically eastern North Dakota, has experienced intense disturbance from agricultural demands and urban sprawl. This study assessed wetlands across the rural, peri-urban, and urban gradient to determine the impacts of urbanization on water quality and vegetation composition. Thirty wetlands were randomly selected and compared based on land use type and the impervious to pervious surface ratio within one mile of each wetland. Water quality samples were taken in 2015 and 2016, and a vegetation assessment was completed at all wetlands. Results indicate disturbance from urbanization impacts wetland water quality and vegetation composition. Rural wetland water quality and vegetation significantly differ from both peri-urban and urban wetlands, whereas peri-urban and urban wetland water quality and vegetation do not differ. Information from this study is useful to wetland professionals across the globe as urban development and sprawl continue to impact wetlands.
172

Phragmites reed beds :: constructed wetlands for municipal wastewater treatment /

Begg, Jonathan S. 01 January 2000 (has links) (PDF)
No description available.
173

Evaporation in a Coastal Subarctic Wetland During the Growing Season

Blanken, Peter 04 1900 (has links)
<p> Energy balance components were measured over a coastal subarctic wetland in northwestern James Bay during the growing season. The Penman-Monteith combination model was used to determine surface and atmospheric controls on evaporation. The Priestley-Taylor combination model was used to calculate an evaporability parameter, a. Combining these two models resulted in determining the sensitivity of a to surface and atmospheric controls. </p> <p> Canopy, aerodynamic, and climatological resistances were influenced by onshore or offshore wind directions. Canopy resistance was dominant and showed a strong seasonal trend a averaged 0.78 and was influenced by wind direction a is most sensitive to canopy resistance, followed by vapour pressure deficit, net available energy, and aerodynamic resistance. </p> / Thesis / Bachelor of Arts (BA)
174

Water Quality in the Cranberry Run Wetland

Houser, Ronald L., Jr. 06 October 2009 (has links)
No description available.
175

Wetlands in the Urban Landscape: The Process of Wetlands Restoration in Baltimore, Maryland and Paris, France

Porter, Abigail M. 16 July 2003 (has links)
No description available.
176

The effects of habitat size and isolation on wetland benthos

Barnes, Karen January 1993 (has links)
</p> I investigated the effects of habitat fragmentation in terms of spatial scale (enclosures of different sizes) and the degree of isolation (different mesh sizes) on benthic macroinvertebrates in the littoral zone of a shallow lake. I hypothesized that decreasing diversity and increasing temporal variation will occur with decreasing size and increasing isolation of enclosures. This hypothesis was tested by examining spatial and temporal variation (coefficient of variation) among replicate enclosures. Variation in benthic diversity was further examined within and among enclosures. The degree of isolation and habitat size interacted to determine variation of species abundance in the benthic community. Specifically, at higher levels of isolation (plastic enclosures), variance among enclosures of the same and of different sizes was the greatest compared to less isolated enclosures. We also investigated the persistence of benthic macroinvertebrates where persistence is defined as constancy in the number of organisms through time. We hypothesized that persistence is lower in small and more isolated enclosures as opposed to large less isolated ones. We simultaneously tested the hierarchical nature of community persistence as outlined by Rahel (1990) to determine if there is a difference in the assessment of persistence of the assemblage depending on the analytical scale used. There is a possible scale effect at the level of abundance rank since small (1 and 4 m2 ) enclosures had lower persistence than large (9 and 16m2 ) enclosures. Low persistence in both abundance and abundance rank over time prevented a conclusive test of the hierarchical nature of community persistence. I conclude that it is important for benthic enclosure experiments to be conducted at various spatial and analytical scales and that, where replication is possible, spatial and temporal variation allows a thorough examination of different community responses. </p> / Thesis / Master of Science (MSc)
177

Characterization of Section 404 Permit Mitigation Plans, Coastal Margin and Associated Watersheds, Upper Texas Coast

Conkey, April A. 14 January 2010 (has links)
A predicted loss of agricultural rice-wetlands and increasing urbanization and development threatens the remaining freshwater wetlands along the upper Texas coast. To avoid, minimize, and mitigate wetland loss, the U.S. Army Corps of Engineers (Corps) is directed to enforce Section 404 of the Clean Water Act (1975 amendment) by administering permits for development. Furthermore, a 1990 Memorandum of Agreement (MOA) between the Corps and the U.S. Environmental Protection Agency (EPA) proposed a national goal of no net wetland loss (NNL). My goals were to identify the frequency of occurrence of freshwater wetland loss due to dredge or fill, assess final plans to mitigate wetland loss, and verify the persistence of the created compensatory wetlands. I created a database of 96 individual, Section 404 permits issued from 1981 to 2001 in the counties of Chambers, Hardin, Jefferson, Liberty, Montgomery, Orange, and San Jacinto (Galveston District Office, U.S. Army Corps of Engineers). Descriptive statistics were calculated for permit characteristics in relation to issue date (pre- or post-NNL). Public comments received from national and state agencies were rank ordered against mitigation plan type to determine Spearman's Rank Order Correlation Coefficient. Visual identification (via site visits and 1996 aerial photos) was used to validate compensatory wetland persistence. Shoreline protection of private property and oil and gas drilling (64% of permit applicants and 59% of impacts) had the greatest effect on wetland loss in the region, particularly Chambers, Jefferson, and Montgomery counties. Overall, 79.3 ha of freshwater wetlands were gained; however, gain was overestimated due to large projects for habitat enhancement. Permits issued post-NNL were more likely to have formal mitigation plans (58% vs. 13% pre-NNL) and allowed no net wetland loss. Although agency comments recommending more formal mitigation plans increased after NNL, only a weak positive correlation was detected (Spearman's r less than or equal to 0.4). Six of seven created wetlands remained in existence through 2006 though they are freshwater ponds replacing more diverse aquatic systems. I recommend the development of a comprehensive method to track wetland loss, mitigation, and changes in watersheds over time.
178

A Study of the Junior High School Student¡¦s Knowledge, Attitude, and Behaviors on Wetland Conservation. ¡ÐA case Study of Kaohsiung's corridor of wetlands

Su, Yu-hung 17 February 2011 (has links)
Kaohsiung's corridor of wetlands is the first of its kind in Taiwan. Therefore, the wetland-related knowledge, attitude, and behavior of the junior high school students are worth exploring and realizing. The main purpose of this study is to explore the student¡¦s background variables (sexual, grade, family socioeconomic status, experience of wetlands, school location) to find out the difference on students¡¦ knowledge, attitude, behavior, and realize the correlation among the ecological conservation of wetlands. The instrument used in this study is the self-compiled questionnaire titled the Kaohsiung junior high school students¡¦ wetland ecological conservation knowledge, attitude, and behavior. The subjects are 891 junior high school students in Kaohsiung city. The data collected are analyzed by descriptive statistics, t tests, single-factor variations data analysis, Pearson product-moment correlation, and etc. The main findings are as follows: 1. The major source of ecological wetland conservation of junior high school students were from the TV & internet, secondly from teachers, parents, and the least was from broadcasting. 2. The students¡¦ knowledge of ecological conservation of wetlands described as good, attitude towards consent and positive, but behavior toward negative. 3. In students¡¦ knowledge of wetland ecological conservation, different grade, family socioeconomic status, and school location exhibited significant differences. However, different sex, and experience of wetlands revealed no significant differences. 4. In students¡¦ attitude of wetland ecological conservation, the experience of wetlands showed significant differences. No significant differences were observed in different sex, grade, family socioeconomic status, and school location. 5. In behavior of wetland ecological conservation, significantly differences were found in different grade, experience of wetlands, and school location. Different sex and family socioeconomic status revealed no significant differences. 6. There was significantly positive correlation between the knowledge and attitude towards wetland ecological conservation of junior high school students; and the significant positive correlation was also found between the attitude and behavior of wetland ecological conservation. There was no significant correlation between the knowledge and behavior towards wetland ecological conservation of junior high school students. Based on the results, several suggestions may be offered for the junior high school in Kaohsiung city, related-educational associations, and future research.
179

Characterization of Section 404 Permit Mitigation Plans, Coastal Margin and Associated Watersheds, Upper Texas Coast

Conkey, April A. 14 January 2010 (has links)
A predicted loss of agricultural rice-wetlands and increasing urbanization and development threatens the remaining freshwater wetlands along the upper Texas coast. To avoid, minimize, and mitigate wetland loss, the U.S. Army Corps of Engineers (Corps) is directed to enforce Section 404 of the Clean Water Act (1975 amendment) by administering permits for development. Furthermore, a 1990 Memorandum of Agreement (MOA) between the Corps and the U.S. Environmental Protection Agency (EPA) proposed a national goal of no net wetland loss (NNL). My goals were to identify the frequency of occurrence of freshwater wetland loss due to dredge or fill, assess final plans to mitigate wetland loss, and verify the persistence of the created compensatory wetlands. I created a database of 96 individual, Section 404 permits issued from 1981 to 2001 in the counties of Chambers, Hardin, Jefferson, Liberty, Montgomery, Orange, and San Jacinto (Galveston District Office, U.S. Army Corps of Engineers). Descriptive statistics were calculated for permit characteristics in relation to issue date (pre- or post-NNL). Public comments received from national and state agencies were rank ordered against mitigation plan type to determine Spearman's Rank Order Correlation Coefficient. Visual identification (via site visits and 1996 aerial photos) was used to validate compensatory wetland persistence. Shoreline protection of private property and oil and gas drilling (64% of permit applicants and 59% of impacts) had the greatest effect on wetland loss in the region, particularly Chambers, Jefferson, and Montgomery counties. Overall, 79.3 ha of freshwater wetlands were gained; however, gain was overestimated due to large projects for habitat enhancement. Permits issued post-NNL were more likely to have formal mitigation plans (58% vs. 13% pre-NNL) and allowed no net wetland loss. Although agency comments recommending more formal mitigation plans increased after NNL, only a weak positive correlation was detected (Spearman's r less than or equal to 0.4). Six of seven created wetlands remained in existence through 2006 though they are freshwater ponds replacing more diverse aquatic systems. I recommend the development of a comprehensive method to track wetland loss, mitigation, and changes in watersheds over time.
180

Construction and Management of Water Environment for the Habitat of Wetland Parks in Urban Areas: A Case Study of Zhou-Zai Wetland Park, Kaohsiung, Taiwan

Chen, Fang-shuan 07 February 2006 (has links)
¡§Zhou-Zai Wetland Park¡¨ is a specific prototype of created wetland ecosystems constructed in urban areas, This park represents integration between development and preservation of a wetland habitat through ecotechnology. It is a created wetland designed to conserve the endangered species of Jacanas in Taiwan, which were suffered from the destruction of habitat in the past. The wetland comprises pool and marsh types of wetland systems, and the inflow of the systems is pumped from the Lian-Chih Lake. Several problems were found when we operated and managed the park including eutrophication, low water exchange rate, and hypoxia in some water areas, emergence, and invasive alien species. The current management strategies are difficult to improve the status. Therefore some suggestions are given to solve such problems including constructing a treatment wetland in injection area in order to improve the water quality of influent and then provide a better water environment of habitat for water fowls as well as to prevent the intrusion of invasive alien species.

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