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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.
141

Elephant space use in relation to ephemeral surface water availability in the eastern Okavango Panhandle, Botswana

Makati, Anastacia 03 July 2023 (has links) (PDF)
The movement and distribution of elephants can be influenced by environmental factors over time (Foley, 2002). Examining how features in the landscape such as vegetation productivity, water sources and anthropogenic activities drive the movement of elephants can help in understanding patterns of movement. It can also help to inform the establishment and alignment of protected areas, wildlife corridors and identification of tourism hotspots as well as policy interventions to manage Human-Elephant Conflict (HEC). The Okavango Panhandle in Botswana is a HEC hotspot and the focus of My study. A number of strategies to address HEC are underway in the area, however one longer term strategy that has been proposed in this area involves provision of artificial water sources to influence elephant movements and keep animals away from fields during the cropping season. However, an improved understanding of how elephants utilize their habitats in relation to natural ephemeral surface water and other factors that influence their movements from dryland habitats to the Okavango Delta resources is needed to inform such management decisions. My study seeks to establish the role of ephemeral surface water on elephant distribution in the eastern Okavango Panhandle, Botswana as well as assess the movement distribution of elephants in relation to the seasonality, proximity and spatial extent of water presence represented by ephemeral surface water. Time series analysis of water extent on ephemeral surface water of the eastern Okavango panhandle will be developed and overlaid with elephant movement datasets. Elephant collar data from 15 elephants (5 males and 10 females) in the eastern Okavango Panhandle, Botswana have been analysed and Home Range (HR) sizes estimated using Kernel Density Estimation (KDE). The relative importance/probability of environmental variables in determining elephants' movement based on the Utilization Distribution (UD) were computed using Generalized Linear Mixed Models (GLMMs). I utilized a remote sensing spectral index, namely the Automated Water Extraction Index (AWEI) to delineate ephemeral surface water in dryland (excluding permanent waters) of the study area. The results reveal that during the wet season, elephants were evenly spread out all over the study area until the early dry season (April-June) when the ephemeral waterholes dried up. Elephants moved southwards towards the permanent waters of the Okavango River, where there are many human settlements and farms. Male HR sizes were found to be bigger than those of female elephants. Wet season (early and late) home range sizes were also bigger when compared to dry season (early and late) HR size. Mean daily distances were computed to investigate the effect of season on elephant daily distances and the distances ranged between 5km and 6.8km in the late wet and in the early wet and late dry season respectively. The Resource Selection Function (RSF) analysis shows that water adjacent sites are preferred over distant ones and both sexes prefer areas with high NDVI, with this preference being more pronounced in males. The seasonal variation of water use is notable in that it affirms the importance of proximity to water for elephants and has implications for their management and HEC. For example, I found that ephemeral surface water has a significant role in influencing elephant spatial use in the area, particularly during the early and late wet season. As ephemeral pans dried and NDVI (vegetation greenness) decreased, elephants started to move closer to the Okavango Delta and consequently human settlements and fields. However, further investigations into the timing of movements away from ephemeral waterholes and the influence of other environmental factors on elephant movements in the area would be needed before any recommendations can be made regarding artificial water provision in this area.
142

A Laboratory Scale Assessment of the Effect of Chlorine Dioxide Pre-Oxidation on Disinfection By-Product Formation for Two Surface Water Supplies

Rodriguez, Angela 01 May 2015 (has links)
Chemical disinfection is the cornerstone of safe drinking water. However, the use of chemical disinfection results in the unintentional formation of disinfection by-products (DBPs), an outcome of reactions between the disinfectant and natural organic matter (NOM) present in the native (raw) water. DBPs are suspected carcinogens, and as such, have been regulated by the U.S. Environmental Protection Agency (USEPA) under the Safe Drinking Water Act (SDWA). This document reports the results of a study that investigated the use of chlorine dioxide pre-oxidation for the reduction of DBP precursors, and subsequently, DBP formation potential (FP). To determine the effectiveness of the chlorine dioxide pre-oxidation process, two surface waters were studied: raw water from Lake Claire (Orlando, FL) and raw water from the East Maui Watershed (Makawao, HI). Lake Claire water contains approximately 11-12 mg/L of NOM and 35 mg/L as CaCO3 of alkalinity, while the Maui source water typically ranges between 7-8 mg/L of NOM with 2-10 mg/L as CaCO3 of alkalinity. Two chlorine dioxide doses were investigated (0.75 mg/L and 1.5 mg/L) and compared to a control to quantify the effectiveness of this advanced pre-treatment oxidation process. Water collected at each site was subject to the following treatment process: oxidation, coagulation, flocculation, sedimentation, ultrafiltration, and disinfection with free chlorine. Disinfection by-product formation potential (DBPFP) analysis showed that ClO2 pre-oxidation, in general, increased the 7-day DBPFP of the East Maui water, and decreased the 7-day DBPFP of the Lake Claire source water. For the Lake Claire water at the higher ClO2 dose, total trihalomethanes (TTHM) were decreased by 37 percent and the five regulated haloacetic acids (HAA5) by 23 percent. For the East Maui source water at the higher ClO2 dose, TTHM’s were increased by 53 percent and HAA5’s by 60 percent. Future research should determine the effect of alkalinity on DBPFP, which could be the reason why chlorine dioxide pre-oxidation caused one water source’s DBPFP to decrease and the other to increase.
143

CHEMICAL MEASURES OF THE GREAT MIAMI WATERSHED: A SEASONAL POSITION WITH MIDWEST BIODIVERSITY INSTITUTE

Day, Rachel Elise 23 January 2014 (has links)
No description available.
144

Multiscale Hyporheic Exchange Through Strongly Heterogeneous Sediments

Pryshlak, Timothy Theodozij 20 May 2015 (has links)
No description available.
145

Evaluation and Mitigation of the Temporal Evolution of Microbial Contamination Risk in Surface Water Systems

Myers, John R. January 2018 (has links)
No description available.
146

Defining Benthic Organism Exposure: Bioavailability and Effects of Non-Polar Organics

Greenberg, Marc Samuel January 2002 (has links)
No description available.
147

Investigation of Spatial and Temporal Groundwater Thermal Anomalies at Zanesville Municipal Well Field, Ohio: Implications for Determination of River-Aquifer Connectivity Using Temperature Data

Holmes, Stuart W. 19 September 2016 (has links)
No description available.
148

Using Contaminant Photoreactivity as a Holistic Indicator to Monitor Changes in Wetland Water Characteristics

Langlois, Maureen Connell 21 October 2011 (has links)
No description available.
149

Design to Promote UrbanEcosystem Services : Examples of solutions with green - blueinfrastructure in public spaces / Bevara och förbättra urbana ekosystemtjänster : En exempelsamling av lösningar för grön-blå infrastruktur på allmänna platser

YIN, XING January 2017 (has links)
The world is increasingly urbanizing with approximately 54% of the world population livingin cities (Langemeyer, 2015). This number is expected to rise to 66% by 2050 (UN, 2014),which means that urbanized areas will expand in size with an additional 2.5 billion new urbaninhabitants (Langemeyer, 2015). Studies show that urban expansion has the effect ofdecreasing, fragmenting, and isolating natural patches by altering the size, shape, andinterconnectivity of the natural landscape (Ricketts, 2001; Alberti, 2005). The consequentloss and degradation of urban and peri-urban green/blue space and elements couldadversely affect ecosystem and its services as well as human health and well-being.Through literature review, the concepts of urban ecosystem services and green-blueinfrastructures are introduced, as well as the main design principles for green-blueinfrastructures. The thesis also briefly introduces urban policies and implementation throughcase study with a focus on Malmö city. Meanwhile, the thesis discusses how the planninginstruments of Green Space Factor and Green Points are used in the Bo01 project and howthey contributed to promote ecosystem services in built environment.Through literature review and case study, the aim of this thesis is to collect design solutionsthat can be used as inspiration and guidance to promote urban ecosystem services throughgreen-blue infrastructures in built environments at different scales.
150

Design to Promote UrbanEcosystem Services : Examples of solutions with green - blueinfrastructure in public spaces / Bevara och förbättra urbana ekosystemtjänster : En exempelsamling av lösningar för grön-blå infrastruktur på allmänna platser

Xing, Yin January 2017 (has links)
The world is increasingly urbanizing with approximately 54% of the world population livingin cities (Langemeyer, 2015). This number is expected to rise to 66% by 2050 (UN, 2014),which means that urbanized areas will expand in size with an additional 2.5 billion new urbaninhabitants (Langemeyer, 2015). Studies show that urban expansion has the effect ofdecreasing, fragmenting, and isolating natural patches by altering the size, shape, andinterconnectivity of the natural landscape (Ricketts, 2001; Alberti, 2005). The consequentloss and degradation of urban and peri-urban green/blue space and elements couldadversely affect ecosystem and its services as well as human health and well-being.Through literature review, the concepts of urban ecosystem services and green-blueinfrastructures are introduced, as well as the main design principles for green-blueinfrastructures. The thesis also briefly introduces urban policies and implementation throughcase study with a focus on Malmö city. Meanwhile, the thesis discusses how the planninginstruments of Green Space Factor and Green Points are used in the Bo01 project and howthey contributed to promote ecosystem services in built environment.Through literature review and case study, the aim of this thesis is to collect design solutionsthat can be used as inspiration and guidance to promote urban ecosystem services throughgreen-blue infrastructures in built environments at different scales.

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