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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.
1

Environmental impact of urban expansion in Ibb City, Yemen : application of GIS and remote sensing

Al-Haj, Mohamed Saleh January 2001 (has links)
No description available.
2

The impact of land cover and land use on the hydrologic response in the Olifants

Ncube, Mthokozisi 23 October 2008 (has links)
Water availability in Southern Africa is highly variable both in time and space, thereby exposing the region to high risks in water availability. This is further compounded by numerous human activities which have significant impact on water resources. The brunt of the risks associated with water scarcity is particularly heaviest on resourceconstrained farmers who depend largely on rain-fed agriculture for subsistence. With continuously increasing demands on the water resources, the need for a better understanding of the hydrological systems becomes crucial as it forms the gateway for providing reliable information for managing water resources. It is also increasingly becoming more important to address land and water linkages because land use decisions are water use decisions. Operational hydrology provides an insight into the effects of man-made changes, the foreseeable hydrological characteristics at a given site, and the long-term prediction of the future hydrological effects of human activities. This provides for a more holistic approach in managing land and water resources as well as the impact of land use on partitioning rainfall into streamflow. This report discusses the application of the SWAT model to the B72E - F quaternary catchments in the Olifants Water Management Area to assess streamflow generation and the effects of human-environment interactions on the hydrology. Results show an expected correlation between land cover and the hydrologic response where an increase in land cover corresponds to a reduction in the streamflow. Range grass shows a higher reduction in the streamflow followed by forestry with arid land giving the highest increase in streamflow. Prediction in the similar neighbouring and ungauged B72A catchment gives a MAR of 68mm. Additionally, a rigorous analysis of the concepts of a local hydrological model, HDAM, is done with respect to rainfall which is the main driver of the model. Modifications of some of the relationships used in the model are suggested with the potential of streamlining the model and making it more applicable in the region.
3

Understanding and Mapping Land-Use and Land-Cover Change along Bolivia's Corredor Bioceancio

Redo, Daniel J. 2010 May 1900 (has links)
The Corredor Bioceanico is a major transportation project connecting the agricultural heartlands of South America to the Atlantic and Pacific coasts. The final link is in southeastern Bolivia - an underdeveloped area that is home to two indigenous groups and globally-significant woodlands and wetlands. Infrastructure developments - comprising a major highway upgrade, revitalized railway services and increased flows along gas pipelines to Brazil - pose major threats to livelihoods and the region's ecological integrity. There are two broad objectives: (i) to map and quantify the spatial patterns of land change using a time-series of coarse and medium resolution satellite imagery; and (ii) to understand the socio-economic and political drivers of change by linking household surveys and interviews with farmers; environmental, climatic, and political data; and classified satellite imagery. Overall, large-scale deforestation has occurred along the Corredor Bioceanico for mechanized commercial production of oil-seed crops such as soybeans and sunflower. The significance of these findings is that agriculture-driven deforestation is pushing into sensitive areas threatening world-renowned ecosystems such as the Chaco, Chiquitano and Pantanal as well as noteworthy national parks. Though quantity remains relatively small compared to other parts of South America, rates of forest loss match or exceed those of more publicized regions such as Rondonia or Mato Grosso, Brazil. Moreover, rates of forest loss are accelerating linearly with time due to policies implemented by incumbent president Evo Morales. Results also show that in the first years of cultivation, pasture is the dominant land-use, but it quickly gives way to intensively cropped farmland. The main findings in terms of percentage area cleared according to forest type is that farmers appear to be favoring transitional forest types on deep and poorly drained soils of alluvial plains. Semi-structured interviews with farmers and representatives of key institutions illustrate that price determined by the global market is not proportionally the most dominant motive driving LULCC in the lowlands of Santa Cruz, Bolivia - an area seen as a quintessential neoliberal frontier.
4

Simulating urban growth for Baltimore-Washington metropolitan area by coupling SLEUTH model and population projection

Zhao, Suwen 18 June 2015 (has links)
This study used two modelling approaches to predict future urban landscape for the Baltimore-Washington metropolitan areas. In the first approach, we implemented traditional SLEUTH urban simulation model by using publicly available and locally-developed land cover and transportation data. Historical land cover data from 1996, 2001, 2006, and 2011 were used to calibrate SLEUTH model and predict urban growth from 2011 to 2070. SLEUTH model achieved 94.9% of overall accuracy for a validation year of 2014. For the second modelling approach, we predicted future county-level population (e.g., 2050) using historical population data and time-series forecasting. We then used future population projection of 2050, aided by strong population-imperviousness statistical relationship (R2, 0.78-0.86), to predict total impervious surface area for each county. These population-predicted total impervious surface areas were compared to SLEUTH model output, at the county-aggregated spatial scale. For most counties, SLEUTH generated substantially higher number of impervious pixels. An annual urban growth rate of 6.24% for SLEUTH model was much higher than the population-based approach (1.33%), suggesting a large discrepancy between these two modelling approaches. The SLEUTH simulation model, although achieved high accuracy for 2014 validation, may have over-predicted urban growth for our study area. For population-predicted impervious surface area, we further developed a lookup table approach to integrate SLEUTH out and generated spatially explicit urban map for 2050. This lookup table approach has high potential to integrate population-predicted and SLEUTH-predicted urban landscape, especially when future population can be predicted with reasonable accuracy. / Master of Science
5

Effects of sugarcane expansion on development and land use and land cover change (LULCC) in Brazil: a case study in the state of Goiás

Link, Tyler January 1900 (has links)
Master of Arts / Geography / Marcellus M. Caldas / As concerns increase over climate change, energy independence, and higher fuel prices, Brazilian sugarcane ethanol is seen as a part of a clean energy future. Brazilian sugarcane ethanol was developed with a long history of government support, and with the introduction of the flex fueled car in 2003, demand rose dramatically. These factors have helped sugarcane expand beyond its traditional regions of Brazil into the Cerrado. More recently however, private capital from both domestic and foreign companies have started investing in Brazilian agriculture and these investments have helped fuel the sugarcane expansion into the Cerrado in the last 15 years. Over 22 sugarcane mills have been constructed in the Brazilian state of Goiás, located in the heart of the Cerrado. The increased investments driving the expansion of sugarcane into the Cerrado brings numerous questions regarding its environmental and social impacts. Thus, the goal of this thesis is to understand how the structural organization of the sugarcane ethanol mills’ affects development at a municipality level in the state of Goiás, Brazil. More specifically, this thesis has two objectives; to evaluate the effects of the sugarcane mills’ influence on land use and land cover change in these municipalities; and to compare how domestic owned mills, foreign owned mills, and jointly owned mills affect socioeconomic development on the municipalities. Three municipalities were analyzed, Edéia, Caçu, and Quirinópolis. Results showed that land use and land cover change varied by municipality. The majority of Edéia’s sugarcane expansion came from lands already in agricultural use. On the other hand, Caçu’s and Quirinópolis’s sugarcane expansion came from pasture lands. However, throughout all the municipalities, sugarcane expansion over native vegetation was small. All three municipalities increased their socioeconomic development levels over the past 20 years as reported on the Human Development Index. In addition, urban survey responses revealed that the residents of Edéia perceived the sugarcane mill had made their lives better than respondents in either Quirinópolis or Caçu. However, this analysis covers only a brief period of time, and future analysis of these, and other municipalities that host sugarcane mills throughout the Cerrado will be needed.
6

Land-use and environmental changes in the Cerrados of South-Eastern Mato Grosso - Brazil

Grecchi, Rosana Cristina January 2011 (has links)
The human-induced changes of the Earth's land surfaces have been unprecedented, with outcomes often indicating degradation and loss of environmental quality. Mato Grosso State in Brazil, location of the study area, underwent extensive land-use and land-cover changes in recent decades with the rates, patterns and consequences poorly documented until now. In this context, the aim of the present research is to propose a multidisciplinary approach for quantifying historical land-use and environmental changes in the southeast part of this State, where the Cerrado biome (Brazilian savannas) has been intensively converted into agricultural lands. The methodology includes three parts: remote sensing change detection, land vulnerability mapping, and identification of key environmental indicators. Land-use/cover information was extracted from a temporal remote sensing dataset using an object-oriented classification approach, and the changes quantified employing a post-classification method. In addition, the study area was assessed for its vulnerabilities, focusing mainly on erosion risks, wetlands, and areas with limited or no suitability for crops. Finally, key environmental indicators were identified from the preceding steps and analyzed within the Organisation for Economic Co-operation and Development (OECD) Pressure-State-Response (PSR) framework. The results provided an improved mapping of the Cerrados natural vegetation conversion into crops and pastures, and indicate that the Cerrado vegetation was intensively converted and also became more fragmented in the time frame studied. Between 1985 and 2005 the area lost approximately 6491 km 2 of Cerrados (42 %). Modeling based on the Universal Soil Loss Equation indicated significant increase in erosion risk from 1985 to 2005 mainly related to the increase in crop areas and the crops' encroachment into more fragile lands.The identification of environmental indicators rendered complex environmental information more generally accessible by structuring it within the PSR framework.The indicators captured key information about land-use and environmental changes in the area, showing that agricultural expansion is the major human activity exerting pressure on natural resources at a landscape scale, and that the pattern of change included high rates of crop expansion and the use of fragile environments such as wetlands and sandy erodable soils.
7

Work streaming / mainstreaming gendered land use and land cover change (GLUCC) : Afro-descendant communities in the Pacific Region of Colombia

Aguirre, Claudia Nancy 28 October 2014 (has links)
This dissertation addresses gender dimensions of Land Use and Land Cover Change (GLULCC) in the last few decades in a collective land titled to Afro-descendant communities in the Pacific region of Colombia, South America, and examines socio-economic and political signifiers affecting land use decisions, rights, and responsibilities. It shows how contrasting but complementary subfields of investigation, Political Ecology and Land Use Science, have contributed ontological, epistemological and practical scholarly works to help better understand the Gender Dimensions of Land Use and Land Cover Change (GLULCC). Historical and current information on environmental, socioeconomic and settlement processes provided a comprehensive portrait of the study area. The remote sensing process (a mainstream method for identifying land use and land cover change) helped exploring the spatial setting of land cover/use, and to reflect on the opportunities and constrains of the steps undertaken during this procedure under the lenses of researching their gendered dimensions. Statistical analyses on both census data (secondary data) and survey sample data (fieldwork data) allowed to establish a set of three groups of gendered land uses, namely, women-akin, men-akin, and gender-blind uses. Exploratory statistics, pairwise correlations, and binary and multinomial logit regression models helped to reassert the latter gendered categories’ assertions. A concluding narrative perspective of GLULCC seeks to further contribute to work streaming/ mainstreaming what I consider may be a scholarly-fertile research line. It hopes to bond, with another perspective, previous theoretical, spatial and quantitative outcomes, under the lenses of the practical experience of fieldwork, which also by way of participatory observation and semi-unstructured interviews brought to the researcher (me) valuable insights and information besides the previous outcomes. Empirical evidence allowed identifying gender-based time allocation, resource-use power relations, and reproductive strategies. Finally, the found rearrangement of settlement spaces and production systems provides practical indications that women´s role on LULCC is well beyond the establishment of small gardens and orchards, or the collection of fuel wood to provide for their families. In contrast, inside this collective title, women’s decisions/strategies have also restructured settlement patterns, and thus, land use dynamics of larger areas at heterogeneous spatial and temporal scales. / text
8

Synoptic Atmospheric Conditions, Land Cover, and Equivalent Temperature Variations in Kentucky

Na-Yemeh, Dorothy Yemaa 01 April 2017 (has links)
Research has demonstrated that equivalent temperature (TE), which incorporates both the surface air temperature (T) and moist heat content associated with atmospheric moisture, is a better indicator of overall heat content. This thesis follows up on a study that used TE to determine the impacts of land use/land cover and air masses on the atmospheric heat content over Kentucky during the growing season (April-September). The study, which used data from the Kentucky Mesonet, reveals that moist weather types dominate the growing season and, as expected, differences between T and TE are smaller under dry atmospheric conditions but larger under moist conditions. For example, the lowest TE-T difference was 10.04 °C on a dry weather day on the 18th of April, 2010 (T = 8.91 °C and TE = 18.95 °C). On the other hand, the highest estimated difference for a day of moist tropical weather was 46.54 °C on the 11th of August, 2010 (T = 26.54 °C and TE = 73.08 °C). Since land cover type influences both moisture availability and temperature in the lower atmosphere, the research shows that TE is larger in areas with higher physical evaporation and transpiration rates. Results support the hypothesis that the influence of different weather types over a region is a likely cause of interannual variation in TE.
9

Monitoring land use and land cover change: a combining approach of change detection to analyze urbanization in Shijiazhuang, China

Liu, Qingling, Gong, Fanting January 2013 (has links)
Detecting the changes of land use and land cover of the earth’s surface is extremely important to achieve continual and precise information about study area for any kinds of planning of the development. Geographic information system and remote sensing technologies have shown their great capabilities to solve the study issues like land use and land cover changes. The aim of this thesis is to produce maps of land use and land cover of Shijiazhuang on year 1993, 2000 and 2009 to monitor the possible changes that may occur particularly in agricultural land and urban or built-up land, and detect the process of urbanization in this city. Three multi-temporal satellite image data, Thematic Mapper image data from year 1993, Enhanced Thematic Mapper image data from 2000 and China Brazil Earth Resource Satellite image data from 2009 were used in this thesis. In this study, supervised classification was the major classification approach to provide classified maps, and five land use and land cover categories were identified and mapped. Post-classification approach was used to improve the qualities of the classified map. The noises in the classified maps will be removed after post-classification process. Normalized difference vegetation index was used to detect the changes of vegetated land and non-vegetated land. Change detection function in Erdas Imagine was used to detect the urban growth and the intensity of changes surrounding the urban areas. Cellular automata Markov was used to simulate the trends of land use and cover change during the period of 1993 to 2000 and 2000 to 2009, and a future land use map was simulated based on the land use maps of year 2000 and 2009. From this performance, the cross-tabulation matrices between different periods were produced to analyze the trends of land use and cover changes, and these statistic data directly expressed the change of land use and land cover. The results show that the agricultural land and urban or built-up land were changed a lot, approximately half of agricultural land was converted into urban or built-up land. This indicates that the loss of agricultural land is associated with the growth of urban or built-up land. Thus, the urbanization took place in Shijiazhuang, and the results of this urban expansion lead to the loss of agricultural land and environmental problems. During the process of detecting the land use and cover change, obtaining of high-precision classified maps was the main problem.
10

A Comparison of Fuzzy Models in Similarity Assessment of Misregistered Area Class Maps

January 2010 (has links)
abstract: Spatial uncertainty refers to unknown error and vagueness in geographic data. It is relevant to land change and urban growth modelers, soil and biome scientists, geological surveyors and others, who must assess thematic maps for similarity, or categorical agreement. In this paper I build upon prior map comparison research, testing the effectiveness of similarity measures on misregistered data. Though several methods compare uncertain thematic maps, few methods have been tested on misregistration. My objective is to test five map comparison methods for sensitivity to misregistration, including sub-pixel errors in both position and rotation. Methods included four fuzzy categorical models: fuzzy kappa's model, fuzzy inference, cell aggregation, and the epsilon band. The fifth method used conventional crisp classification. I applied these methods to a case study map and simulated data in two sets: a test set with misregistration error, and a control set with equivalent uniform random error. For all five methods, I used raw accuracy or the kappa statistic to measure similarity. Rough-set epsilon bands report the most similarity increase in test maps relative to control data. Conversely, the fuzzy inference model reports a decrease in test map similarity. / Dissertation/Thesis / M.A. Geography 2010

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