Open Access. Powered by Scholars. Published by Universities.®

Social and Behavioral Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Social and Behavioral Sciences

Vulnerability Of Protected Areas To Human Encroachment, Climate Change And Fire In The Fragmented Tropical Forests Of West Africa, Francis Kwabena Dwomoh Jan 2018

Vulnerability Of Protected Areas To Human Encroachment, Climate Change And Fire In The Fragmented Tropical Forests Of West Africa, Francis Kwabena Dwomoh

Electronic Theses and Dissertations

The Upper Guinean region of West Africa is home to some of the most globally significant tropical biodiversity hotspots, providing ecosystem services that are crucial for the region’s socio-economic and environmental wellbeing. Nonetheless, following decades of human-caused destruction of natural habitats, protected areas currently remain the only significant refugia of original vegetation relics in landscapes that are highly fragmented. Aside from having strong geographic variation in land use, climate, vegetation, and human population, the region has also experienced remarkable biophysical and socio-economic changes in recent decades. All these factors influence the fire regime and the vulnerability of forests within protected …


Satellite Remote Sensing Of Woody And Herbaceous Leaf Area For Improved Understanding Of Forage Resources And Fire In Africa, Milkah Njoki Kahiu Jan 2018

Satellite Remote Sensing Of Woody And Herbaceous Leaf Area For Improved Understanding Of Forage Resources And Fire In Africa, Milkah Njoki Kahiu

Electronic Theses and Dissertations

In sub-Saharan Africa (SSA) tree-grass systems commonly referred to as savannas dominating drylands, play a critical role in social, cultural, economic and environmental systems. These coupled natural-human systems support millions of people through pastoralism, are important global biodiversity hotspots and play a critical role in global biogeochemical cycles. Despite the importance of SSA savannas, they have been marginalized for years as most governments neglect dryland resources in favor of agricultural research and development assistance. Hence, lack of spatially and temporally accurate information on the status and trends in savanna resources has led to poor planning and management. This scenario calls …


Cross Calibration And Validation Of Landsat 8 Oli And Sentinel 2a Msi, M. M. Farhad Jan 2018

Cross Calibration And Validation Of Landsat 8 Oli And Sentinel 2a Msi, M. M. Farhad

Electronic Theses and Dissertations

This work describes a proposed radiometric cross calibration between the Landsat 8 Operational Land Imager (OLI) and Sentinel 2A Multispectral Instrument (MSI) sensors. The cross calibration procedure involves i) correction of the MSI data to account for spectral band differences with the OLI; and ii) correction of BRDF effects in the data from both sensors using a new model accounting for the view zenith/azimuth angles in addition to the solar zenith/view angles. Following application of the spectral and BRDF corrections, standard least-squares linear regression is used to determine the cross calibration gain and offset in each band. Uncertainties related to …


A Study Of African Savanna Vegetation Structure, Patterning, And Change, Christoffer R. Axelsson Jan 2018

A Study Of African Savanna Vegetation Structure, Patterning, And Change, Christoffer R. Axelsson

Electronic Theses and Dissertations

African savannas cover roughly half of the continent, are home to a great diversity of wildlife, and provide ecosystem services to large populations. Savannas showcase a great diversity in vegetation structure, resulting from variation in climatic, edaphic, topographic, and biological factors. Fires play a large role as savannas are the most frequently burned ecosystems on Earth. To study how savanna vegetation structure shifts with environmental factors, it is necessary to gather site data covering the full gradient of climatic and edaphic conditions. Several earlier studies have used coarse resolution satellite remote sensing data to study variation in woody cover. These …


Biomass Burning In The Conterminous United States: A Comparison And Fusion Of Active Fire Observations From Polar-Orbiting And Geostationary Satellites For Emissions Estimation, Fangjun Li Jan 2018

Biomass Burning In The Conterminous United States: A Comparison And Fusion Of Active Fire Observations From Polar-Orbiting And Geostationary Satellites For Emissions Estimation, Fangjun Li

Electronic Theses and Dissertations

Biomass burning is an important source of atmospheric greenhouse gases and aerosol emissions that significantly influence climate and air quality. Estimation of biomassburning emissions (BBE) has been limited to the conventional method in which parameters (i.e., burned area and fuel load) can be challenging to quantify accurately. Recent studies have demonstrated that the rate of biomass combustion is a linear function of fire radiative power (FRP), the instantaneous radiative energy released from actively burning fires, which provides a novel pathway to estimate BBE. To obtain accurate and timely BBE estimates for near real-time applications (i.e., air quality forecast), the satellite …


Mapping And Risk Assessment Of Juniper Encroachment Into A Prairie Landscape, Kyle D. Kaskie Jan 2018

Mapping And Risk Assessment Of Juniper Encroachment Into A Prairie Landscape, Kyle D. Kaskie

Electronic Theses and Dissertations

Juniper encroachment is a considerable threat to the prairie ecosystems of the Great Plains because it has the potential to alter native grasslands by changing soil characteristics, limiting herbaceous biomass, and hindering native community regeneration. Accurate maps of juniper cover and predictions of areas at risk for future expansion are needed to support proactive management measures. Therefore, our objectives are to: (1) Develop a practical workflow for large-scale juniper mapping using Landsat 8 Operational Land Imager (OLI) imagery and partial unmixing techniques, (2) Compare the classification accuracies from the resulting map based on different juniper density thresholds and different types …