UMD Theses and Dissertations
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Item Interdisciplinary Geospatial Assessment of Malaria Exposure in Ann Township, Myanmar(2020) Hall, Amanda Hoffman; Loboda, Tatiana V; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Despite considerable progress toward malaria elimination in Myanmar, challenges remain owing to the persistence of complex focal transmission reservoirs. Nearly all remaining infections are clinically silent, rendering them invisible to routine monitoring. Moreover, limited knowledge of population distributions and human activity on the landscape in remote regions of Myanmar hinders the development of targeted malaria elimination approaches, as advocated by the World Health Organization (WHO). This is especially true for Ann Township, a remote region of Myanmar with a high malaria burden, where a comprehensive understanding of local exposure, which includes the characterization of environmental settings and land use activities, is crucial to developing successful malaria elimination strategies. In this dissertation, I present an interdisciplinary approach that combines satellite earth observations with two separate on-the-ground surveys to assess human exposure to malaria at multiple scales. First, I mapped rural settlements using a fusion of Landsat imagery and multi-temporal auxiliary data sensitive to human activity patterns with a classification accuracy of 93.1%. A satellite data-based map of land cover and land use was then used to assess landscape-scale malaria exposure as a function of environmental settings for a subset of ten villages where a malaria prevalence survey was carried out. While multiple significant associations were discovered, the relationship found between malaria exposure and satellite-measured village forest cover was the most significant. Finally, a separate detailed survey that explored a variety of land use activities, including their frequency and duration along with testing for clinical or subclinical malaria, was used to identify and quantify factors promoting an individual’s likelihood of malaria infection regardless of the environmental settings. This analysis established strong associations between malaria and individual land use activities that bring respondents into direct contact with forested areas. These results highlight that the current Myanmar malaria elimination strategies, which focus on prevention from within the home (i.e., bednets and indoor spraying), are no longer sufficient to remove remaining malaria reservoirs in the country. A paradigm shift in malaria elimination strategies towards targeted interventions that can disrupt malaria transmission in the settings where the exposure occurs are critical to achieving country-wide malaria elimination.Item ENVIRONMENTAL IMPACTS OF CHANING DIETARY QUALITY(2018) He, Pan; Baiocchi, Giovanni; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The food sector has been recognized as a significant contributor to multiple environmental issues including GHG emissions, water shortage and contamination, ecological disruption, etc., while the malnutrition issues has been increasingly affecting global public health over the years, especially in developing countries such as China where the diet patterns have been shifting considerably over the decades. To develop a sustainable diet that can minimize the environmental impact while meeting nutritional quality targets within economic affordability and cultural acceptability, knowledge is required on how these aspects are interconnected via dietary patterns not only for different countries but also across heterogeneous subnational socio-economic status. The overall aim of this research is to quantitatively evaluate the environmental impacts and nutritional quality of different dietary patterns characterized by socio-economic status. With this overarching question, this study explores three specific research questions that address the historical and assumed dietary patterns at different scales: 1) How have the environmental impact of the Chinese dietary patterns changed with the human nutritional quality for different socio-economic groups over the years? 2) How would an improvement in nutrition quality change the dietary environmental footprints in China? 3) How would the global adoption of healthy diets affect the environmental impacts in each country caused by agricultural production? This dissertation is a synthesized analysis combining the environmental impact accounting and dietary quality evaluation. It links individual food consumption records with environmental impact factors and dietary recommendations to quantitatively analyze the nutrition-environmental nexus for individuals from different income groups, living areas, and countries, and compare how such nexus differ by these socio-economic features. In this way, this dissertation identifies opportunities and challenges in achieving a “win-win” solution for protecting the natural environment and improving public health jointly for individuals from various socio-economic contexts. Its findings provide implications for goal setting and cost-benefit analysis of integrative policymaking concerning joint nutrition development and environmental management.Item IMPACT OF LAND SURFACE VEGETATION CHANGE OVER THE LA PLATA BASIN ON THE REGIONAL CLIMATIC ENVIRONMENT: A STUDY USING CONVENTIONAL LAND-COVER/LAND-USE AND NEWLY DEVELOPED ECOSYSTEM FUNCTIONAL TYPES(2010) Lee, Seung-Jae; Berbery, Ernesto H; Atmospheric and Oceanic Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Naturally occurring or human induced changes in land surface vegetation have been recognized as one of the important factors influencing climate change. The La Plata Basin in South America has experienced significant changes in structural land-cover/land-use types, and those changes can involve changes in the surface physical properties such as albedo and roughness length, evapotranspiration, infiltration, and water storage eventually affecting the development of precipita-tion and the hydroclimate of the basin. In this study, the Weather Research and Forecast (WRF) modeling system was employed to investigate the role of changing land surface conditions in the La Plata Basin. For this purpose, ensembles of seasonal simulations were prepared for a control case and two extreme land cover scenarios: the first one assumes an expansion of the agricultural activities and the second one assumes a "natural" vegetation cover where no croplands are present. An extreme anthropogenic land-cover change -simulating an extensive agricultural practice- implies that the northern part of the basin, where croplands replace forests and savannah, would experience an overall increase in albedo and reduced surface friction. The two changes lead to a reduction of sensible heat and surface temperature, and a somewhat higher evapotranspiration due to decreased stomatal resistance and stronger near-surface winds. The effect on sensible heat seems to dominate and leads to a reduction in convective instability. The stronger low level winds due to reduced friction also imply a larger amount of moisture advected out of the basin, and thus resulting in reduced moisture flux convergence (MFC) within the basin. The two effects, increased stability and reduced MFC, result in a reduction of precipitation. On the other hand, the southern part of the basin exhibits the opposite behavior, as crops would replace grasslands, resulting in reduced albedo, a slight increase of surface temperature and increased precipitation. Notably, the results are not strictly local, as advective processes tend to modify the circulation and precipitation patterns downstream over the South Atlantic Ocean. A newly developed land surface classification, so-called Ecosystem Functional Types (EFTs, systems that share homogeneous energy and mass exchanges with the atmosphere), is implemented in the WRF model to explore its usefulness in regional climate simulations of surface and atmospheric variables. Results show that use of the EFT data improves the climate simulation of 2-m temperature and precipitation, making EFTs a good alternative to land cover types in numerical climate models. An additional advantage of EFTs is that they can be calculated on a yearly basis, thus representing the interannual variability of the surface states. During dry years the 2-m temperature and 10-m wind are more sensitive to changes in EFTs, while during wet years the sensitivity is larger for the 2-m water vapor mixing ratio, convective available potential energy, vertically-integrated moisture fluxes and surface precipitation. This indicates that the impact of land-cover and land-use changes on the climate of the LPB is dependent not only on the wetness of the year, but also on the meteorological or climate variables. Comparisons with observations show that the simulated precipitation difference induced by EFT changes resembles the overall pattern of observed precipitation changes for those same years over the LPB. In the case of the 2-m temperature, the simulated changes due to EFT changes are similar to the observed changes in the eastern part and the southern part of the basin (especially in Uruguay), where t he strongest EFT changes occurred.Item Watershed land use and nutrient dynamics in Maryland Coasal Bays, U.S.A.(2008) Beckert, Kristen A.; O'Neil, Judith M.; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Upstream and inshore regions of the Maryland Coastal Bays exhibit degraded water quality. Six streams and three shallow bays were sampled in May and July 2006 and 2007 to compare spatial patterns in relation to land use and nutrient loading. St. Martin River, having a high percentage of crop agriculture and a low percentage of forest and wetlands, experienced the most degraded water quality of the three regions, and stream total nitrogen in its watershed was linked to feeding operations and anthropogenic land use. Despite having a much less developed watershed, Johnson Bay experienced degraded water quality, especially in inshore regions. Sinepuxent Bay had the best water quality of the three bays, but still demonstrated anthropogenic impacts. Nutrient loading from land use is directly related to the observed patterns in St. Martin River, while residence time, groundwater flows, and within-bay cycling has led to water quality degradation in Johnson Bay.Item Evaluation of Nitrogen Nonpoint-source Loadings using High Resolution Land Use Data in a GIS: A Multiple Watershed Study for the State of Maryland.(2008-08-14) Ahmed, Sarah Naveed; Moglen, Glenn E; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The performance of three monitoring perspectives, for the detection of watershed compliance with water quality standards, was evaluated. In order to compare performances 35 watershed nonpoint-source nitrogen loading cases were calculated within a GIS. Calculations showed that the probability of loads exceeding a criterion at the watershed outlet is more representative of upstream conditions than a nominal mean load comparison at the watershed outlet. Combined outlet compliance interpretations were found to isolate loading conditions that on average did not exceed the criterion; however, variations within loading distributions were large such that compliant conditions were threatened. The whole watershed perspective mapped the relationship between stream network structure, land cover/land use, and loadings. Comparisons between the perspectives suggested that both outlet perspectives usually are consistent with whole watershed conditions. Semivariograms were demonstrated to characterize spatial variability in loadings and predict the accuracy with which monitoring sites represent loads at upstream locations.Item The regulation of bacterioplankton carbon metabolism in a temperate salt-marsh system(2005-09-21) Apple, Jude Kolb; del Giorgio, Paul A.; Kemp, W. Michael; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study describes an investigation of the factors regulating spatial and temporal variability of bacterioplankton carbon metabolism in aquatic ecosystems using the tidal creeks of a temperate salt-marsh estuary as a study site. Differences in land-use and landscape characteristics in the study site (Monie Bay) generate strong predictable gradients in environmental conditions among and within the tidal creeks, including salinity, nutrients, and the quality and quantity of dissolved organic matter (DOM). A 2-yr study of bacterioplankton metabolism in this system revealed a general positive response to system-level nutrient enrichment, although this response varied dramatically when tidal creeks differing in salinity were compared. Of the numerous environmental parameters investigated, temperature and organic matter quality had the greatest influence on carbon metabolism. All measures of carbon consumption (i.e., bacterioplankton production (BP), respiration (BR) and total carbon consumption (BCC)) exhibited significant positive temperature dependence, but the disproportionate effect of temperature on BP and BR resulted in the negative temperature dependence of bacterioplankton growth efficiency (BGE = BP/[BP+BR]). Dissolved organic matter also had an influence on carbon metabolism, with higher BCC and BGE generally associated with DOM of greater lability. Our exploration of factors driving this pattern suggests that the energetic content and lability of DOM may be more important than nutrient content or dissolved nutrients alone in determining the magnitude and variability of BGE. Investigations of single-cell activity revealed that BCC and BGE may be further modulated by the abundance, proportion, and activity of highly-active cells. Differences in single-cell activity among creeks differing in freshwater input also imply that other cellular-level properties (e.g., phylogenetic composition) may be an important factor. Collectively, results from this research indicate that the variability of bacterioplankton carbon metabolism in temperate estuarine systems represents a complex response to a wide range of environmental and biological factors, of which temperature and DOM quality appear to be the most important. Furthermore, this research reveals fundamental differences in both cellular and community-level metabolic processes when freshwater and marine endmembers of estuaries are compared that may contribute to the variability in bacterioplankton carbon metabolism within and among estuarine systems.Item An Analysis of Pedestrian-Vehicular Crashes Near Public Schools in the City of Baltimore, Maryland(2005-05-04) Fults, Kandice Kreamer; Clifton, Kelly J; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In previous research, children have been shown to be involved in pedestrian-vehicular crashes in high numbers due to improper pedestrian behaviors. Little research has been conducted to examine the relationship between schools and pedestrian crashes. This study analyzes pedestrian-vehicular crashes in the City of Baltimore, Maryland to determine any relationships that may exist between crashes near public schools and the physical and social attributes of these schools. It was found that the presence of a driveway decreases crash occurrence and severity. A setback from the road will decrease crash occurrence but increase the severity of the crashes. The presence of off-street parking was shown to increase the severity of a crash, particularly for children ages 16-18. Recreational facilities are shown to increase the crash occurrence and severity of crashes. This study however, is limited as it does not include pedestrian demand data and the results should be interpreted as such.Item Pedestrian-Vehicular Crashes: The Influence of Personal and Environmental Factors(2005-05-03) Burnier, Carolina Valdemarin; Clifton, Kelly J; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This thesis examines the relationship between land use and pedestrian-vehicle crashes. Analysis focuses on how the pedestrian crashes vary by personal characteristics (age, sex, condition, and severity of injury) and physical characteristics of the crash area (location type, population density, land use, pedestrian activity, and demand). The data for this study are pedestrian- vehicle crashes in Baltimore City, MD occurring between 2000 and 2002, supplied by the State of Maryland Motor Vehicle Accident Report. The results from the analysis suggest that in general, there are significant effects of land use on pedestrian crashes and, more importantly, pedestrian exposure. When controlling for demand, urban downtown areas with high population and roadway densities and good commercial accessibility are found to have negative relationships to pedestrian exposure. The results may justify the promoting of denser urban neighborhood designs and advocate the need to guide safety policy investments to these urban areas with high pedestrian activity.Item INTEGRATED ECOLOGICAL ECONOMIC MODELING OF ECOSYSTEM SERVICES FROM THE BRAZILIAN AMAZON RAINFOREST(2004-10-26) Portela, Rosimeiry G.; Costanza, Robert; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation links the natural and social sciences, using modeling techniques to enhance understanding of the functioning of a complex ecosystem and its relevance to humans. For this purpose, I developed a Regional Unified Metatomodel of the Brazilian Amazon (RUMBA) to simulate the Amazon forest provision of ecosystem goods and services and their contribution to human economy and welfare. The model was also used to simulate the potential effect of an incentive to reduce deforestation in return for a payment for avoided releases of carbon into the atmosphere. Simulation was done from 1975 to 2100, with calibration performed for the first 25 years, and for four scenarios: a baseline scenario, based on historical trends, and four alternative scenarios based on different assumptions and policy choices. The baseline scenario shows deforestation proceeding at high rates, leading to decreasing provision of forest goods and services and increasing economic growth. The growth of GRP per capita, on the other hand, remains much smaller than that of GRP. Regional welfare decreases significantly over the simulated period. The overall monetary contribution of ecosystem goods and services to the regional economy is estimated as 5 times the GRP in year 2100. Scenarios of increased investment in development yielded higher economic growth accompanied by lower levels of welfare, while opposite trends were found for scenarios of higher investment in human, knowledge and natural capital. Finally, results also show that in order for a monetary compensation to represent a significant incentive to land owners to reduce deforestation, higher prices for avoided carbon emissions would have to be set than current prices of the emerging carbon market. Main research findings are that increasing land use change in the Brazilian Amazon incurs significant losses of ecosystem services without this being adequately offset by increasing monetary income or welfare of people. This reseach has also found that in the absence of significant incentives from global beneficiaries for any one ecosystem service, or a combination of incentives addressing several types of ecosystem services, rational land uses at the local level lead to sub-optimal provision of these services from the global perspective.