College of Behavioral & Social Sciences
Permanent URI for this communityhttp://hdl.handle.net/1903/8
The collections in this community comprise faculty research works, as well as graduate theses and dissertations..
Browse
3 results
Search Results
Item Landsat Analysis Ready Data for Global Land Cover and Land Cover Change Mapping(MDPI, 2020-01-29) Potapov, Peter; Hansen, Matthew C.; Kommareddy, Indrani; Kommareddy, Anil; Turubanova, Svetlana; Pickens, Amy; Adusei, Bernard; Tyukavina, Alexandra; Ying, QingThe multi-decadal Landsat data record is a unique tool for global land cover and land use change analysis. However, the large volume of the Landsat image archive and inconsistent coverage of clear-sky observations hamper land cover monitoring at large geographic extent. Here, we present a consistently processed and temporally aggregated Landsat Analysis Ready Data produced by the Global Land Analysis and Discovery team at the University of Maryland (GLAD ARD) suitable for national to global empirical land cover mapping and change detection. The GLAD ARD represent a 16-day time-series of tiled Landsat normalized surface reflectance from 1997 to present, updated annually, and designed for land cover monitoring at global to local scales. A set of tools for multi-temporal data processing and characterization using machine learning provided with GLAD ARD serves as an end-to-end solution for Landsat-based natural resource assessment and monitoring. The GLAD ARD data and tools have been implemented at the national, regional, and global extent for water, forest, and crop mapping. The GLAD ARD data and tools are available at the GLAD website for free access.Item ENDANGERED DRY DECIDUOUS FORESTS OF UPPER MYANMAR (BURMA): A MULTI-SCALE APPROACH FOR RESEARCH AND CONSERVATION(2006-09-11) Songer, Melissa A.; DeFries, Ruth S.; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Tropical dry forests are critically endangered and largely unprotected ecosystem. I used a multi-scale research approach to study Upper Myanmar's dry deciduous forests. At the broad scale I assessed how well existing land cover data can be used to map and monitor dry forests, and estimated the extent, distribution, and level of protection of these forests. At the landscape level I assessed spatial and temporal dynamics of deforestation in and around a dry forest protected area, Chatthin Wildlife Sanctuary (CWS), investigated land use pressures driving these changes, and evaluated effectiveness of protection efforts within the sanctuary. At the local scale I studied the degree to which people rely on dry forests for subsistence and the socioeconomic variables correlated with dependence on forest products. Using MODerate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data to delineate remaining dry deciduous forests, I found that only 24,000 km2 of this forest type remain in Upper Myanmar--only 4% inside protected areas. At 81% accuracy, this map scored higher than existing global and regional land cover classifications for predicting dry forest. Employing satellite images covering the landscape in and around CWS (Landsat MSS, TM, ETM+ and ASTER) between the years 1973-2005 , I found that 62% of forest was lost (1.93% annual rate) primarily from agricultural conversion and hydroelectric development. Sanctuary protection has been effective in slowing decline: loss rates inside CWS were 0.49% annually (16% total). However, forest inside the sanctuary is still declining at a rate above the global average and shows evidence of impact from forest product extraction around the boundaries. Based on interviews with 784 people living in 28 subsistence-based agricultural communities located in and around CWS, I found virtually all survey respondents depended on CWS for food, medicine, housing materials, and, above all, fuelwood. Poverty and socioeconomic limitations drive extractive activities. While CWS has been effective in slowing deforestation rates, alternative use strategies that benefit people will improve prospects for long-term conservation in the area. My results demonstrate that a multi-scaled research approach is essential for understanding the drivers impacting the rapidly-declining dry forests of Upper Myanmar.Item ANALYZING FOREST CHANGE AND POLICY IN WASHINGTON, DC SUBURBAN COUNTIES(2005-05-27) Jantz, Claire Ann; Geores, Martha E; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Geographical approaches for landscape studies have emphasized the interpretation of landscape change as a cultural phenomenon, but often have neglected modern geographic techniques, such as remote sensing observations and quantitative spatial analysis, to characterize and understand landscape change. This study attempts to bridge these gaps by integrating a socio-cultural analysis of land use policy formation and quantitative assessments of land cover change to demonstrate how policy decisions can influence forest landscape patterns in suburban areas. Historical data from Montgomery County, MD and Fairfax County, VA, two counties adjacent to the Washington, DC urban core that have different governmental structures, were assembled and analyzed. A policy database was developed and analyzed using qualitative techniques, such as grounded theory and content analysis, to address questions related to policy formation and trends. Key findings included the identification of a strong link between land use policies and the broader environmental discourse, demonstrating that dominant cultural values are institutionalized in the development of land use policy. Furthermore, many policies related to forest management and preservation, particularly in recent decades, had a strong focus on protecting riparian forests. Land cover change between the late 1930s and 1998 was studied for local case study areas using time series of aerial photographs, and between 1990 and 2000 across both counties using satellite-derived land cover maps. Using a statistical technique, weights of evidence, the processes of new development, deforestation, and forest persistence were modeled. The results highlighted the role of biophysical variables, such as steep slopes and the presence of poorly drained soils, in constraining new development and enhancing forest persistence. However, the role of land use policies was also evident in enhancing forest persistence through the establishment of protected areas and riparian protection policies. This study demonstrated the impact that land use regulations can have on the evolution of forested landscape patterns within the built environment. The links between socio-cultural values and policy formation highlighted the institutional and cultural barriers that prevent rapid shifts in policy orientation, despite social and environmental problems that arise within a rapidly changing landscape.