Browsing by Author "Rijal, Santosh"

Now showing 1 - 9 of 9
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    Climate change, perceived human environment changes, and adaptation responses in coastal Indigenous community of Akplabanya, Ghana
    Ayesu-Danso, Brandy (Virginia Tech, 2024-01-23)
    Coastal communities are facing unprecedented challenges as impacts of climate change continue to escalate globally. Rising sea levels, intensified storm activity, and coastal erosion are extreme climate impacts noticed frequently in coastal communities. Indigenous coastal communities in Ghana are impacted by these extreme climate impacts. In this thesis, I studied the perceived human-environment changes in Indigenous community of Akplabanya. Akplabanya community on the coast of Ghana is experiencing changes in their cultural heritage, environmental surroundings, and their climate. This thesis sought to explore adaptation dynamics within Akplabanya and offer insights into their human-environmental changes and resilience in the face of climate change. In studies that focus on Ghana, little is known about the changes of human-environment interaction in Akplabanya, or their Indigenous peoples' responses to those changes. The two objectives of this study are: 1). To identify changes in coastal human-environment interactions as perceived by the Akplabanya Indigenous community, and 2). To examine the human adaptation responses of the Akplabanya community to the changes in their coastal human-environment interactions. I used four qualitative data collection methods. Semi-structured interviews (n=61) enlisted personal experiences and insights on changing environment and adaptation responses. Key informant interviews (n=28) provided additional insights into context and history. Focused group discussions (n=3), each comprising five participants, focused the community's collective narratives on changing environment and adaptation responses. Participant observation conducted throughout data collection helped me to understand daily life of Akplabanya. Data collection occurred over a period of two months (December 2022-February 2023). I found five themes to explain Akplabanya's perceptions about the changes of coastal human-environment interactions. They are: 1). Biodiversity loss (e.g. vegetation loss), 2). Pollution (e.g. unsustainable practices), 3). Coastal climate change (e.g. coastal erosion), 4). Resource change (e.g. freshwater change), and Population change (e.g. increasing population). I also built participant responses that addressed objective 2 on themes of place, agency, collective action, institutions, coastal Indigenous knowledge, and learning. The findings built on these themes highlights changes in coastal human-environment interactions in coastal fisheries, water systems, land utilization, livestock management, architectural practices, and the preservation of Indigenous knowledge in Akplabanya.
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    Developing Production Techniques and A Site Assessment Tool for Forest Farmed Ramps in Appalachia
    Aryal, Pabitra (Virginia Tech, 2023-06-23)
    The Allium tricoccum Aiton (ramps, aka wild leeks), a native spring ephemeral, is a cultural keystone species in Appalachia, a mountainous physiographic region encompassing 205,000 square miles of the eastern United States. People in Appalachia have long harvested ramps in the wild. However, growing demand for the plant in and outside the region has increased harvesting, resulting in threats to native populations. Agroforestry cultivation techniques and technical support for sustained-yield forest farming practices are needed to conserve ramps and meet increasing demand. Various techniques for assessing suitable production practices for ramps were explored in this dissertation, particularly examining best-suited ramp ecotypes, mycorrhizal treatment, and habitat suitability determination. In the first study, bulbs and seeds from diverse Appalachian locations were gathered and transplanted to a common experimental site to investigate the effects of different ramp ecotypes on growth, survival, and stress responses. Plant characteristics and stress measurements were recorded before transplantation and post-transplantation assessments. Specifically, the study investigated the germination rate of three ramp seed ecotypes and the growth, survival, and stress responses of eight native ramp bulb ecotypes and three commercially obtained seedling samples. Results indicated that above-ground growth, survival, and stress response on the ramp ecotypes differed significantly. The second study explored the impact of mycorrhizae on ramps and was evaluated by assessing the impact of Arbuscular Mycorrhizal Fungi (AMF) inoculation on Allium tricoccum. Four measurements, collectively referred to as parameter categories, were assessed. These included measures of 1) above-ground plant growth: leaf length, and leaf width; 2) stress measurement: transplant stress after a few days of transplant, and photosynthetic performance stress after a year of transplant; 3) survival analysis; and 4) mycorrhizal colonization rate. For each parameter category, three treatment comparison categories were conducted: 1) Positive control treatments: bulbs were planted from their native environment without treatment; 2) Negative controls: bulbs were treated with fungicide before planting to eradicate existing AMF in roots; and 3) The test group: bulbs were inoculated with commercial AMF (Atriva 500). Results indicated that mycorrhizal inoculation could increase ramp leaf length (P≤0.03). However, the impact varied by ecotype, highlighting the importance of considering local environmental conditions and ramp ecotype. Mycorrhizal inoculation did not impact ramp growth at the seedling stage. Mycorrhizal treatment increased the transplanted ramp's survival and stress tolerance (P≤0.001). The third study used multi-criteria decision-making (MCDM), the Analytic Hierarchical Process (AHP), and weighted linear combinations to model suitable habitats for ramps production. Ten habitat criteria were chosen (including five soil properties, three topographic parameters, and two land use properties) to assess the potential for growing ramps in seven counties in Virginia, West Virginia, Pennsylvania, and North Carolina. The percentage of highly suitable areas for ramps production in the studied counties ranges from 21.5% in Haywood County to 49.6% in Macon County. Similarly, moderately suitable areas range from 36.7% in Macon County to 54.5% in Lawrence County. Ground truthing was performed to validate the model. Ramp patch locations within each county were geocoded in the final suitability maps. Existing ramp patches were within the model's estimate of moderate to high site suitability ranges, suggesting the model is valid. Results of the study suggest that site suitability modeling could be useful for producers interested in growing ramps in forest farm settings across Appalachia.
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    Entrepreneurship-based factors to foster climate adaptation among Indigenous communities
    Ebawala Pitiyalage, Indunil Prabodha Dharmasiri (Virginia Tech, 2024-01-25)
    Entrepreneurship-based factors to foster climate adaptation among Indigenous communities Indunil Prabodha Dharmasiri Ebawala Pitiyalage ABSTRACT (ACADEMIC) This thesis investigates the factors that cause the emergence of entrepreneurship to foster climate adaptation responses among Indigenous communities. These factors can influence, enhance, or degrade the potential for entrepreneurship in the climate change adaptation context. While these factors are well-studied for non-Indigenous communities, they remain understudied for Indigenous communities' contexts. The objectives of this study are to identify the factors that shape the emergence of entrepreneurship to foster adaptive responses to climatic risks faced by Indigenous communities and to assess the identified entrepreneurship-based factors through a case study. I followed a two-stepped methodological approach through a systematic literature review and a case study analysis among Sri Lankan Indigenous 'Vedda' communities. The systematic review included 65 peer-reviewed articles from the Web of Science and Scopus databases, and the case study analysis involved 90 in-depth semi-structured interviews with nine Indigenous communities in Sri Lanka. I found 15 entrepreneurship-based factors that shape the emergence of entrepreneurship to foster climate adaptation. I categorized those 15 factors under five key themes. They are learning (crop failure, learning, prior entrepreneurial experience), institutions (social networks, institutional support, overcoming the agency-structure paradox), place (resource (un)availability, location, environmental risk factors), capacity (access to information, entrepreneurs' psychological traits, access to capital) and strategy (business characteristics, product range, market characteristics). I applied these factors to the Sri Lankan Indigenous community context and assessed them through case studies. My study frames the potential of entrepreneurship to foster climate adaptation among Indigenous communities. Further, the study provides insights for scholars, practitioners, and policymakers in making climate change adaptation-related Indigenous policies and broader-level applications, such as the development of new adaptation measures to reduce the risks of climatic changes through entrepreneurship.
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    Governing Indigenous food systems: Global practices and local realities in Sri Lanka
    Jayasekara Pathiranage, Sithuni Mimasha (Virginia Tech, 2025-01-09)
    This thesis focuses on advancing the understanding of Indigenous food system governance. Indigenous communities inhabit various geographical areas, each encountering distinct climate changes that affect their food systems. Specific governance strategies designed to address these unique climate changes are crucial for maintaining food security within Indigenous populations. Academic research has explored Indigenous food systems, food security issues among Indigenous populations, and factors affecting food security; yet, the current literature is insufficient to tackle food security challenges because the governance dimensions of Indigenous food systems have yet to be examined. Additionally, Indigenous research has mostly been limited to specific regions. Specifically, Sri Lankan Indigenous peoples, known as 'Vedda,' remain understudied. In this context, there is a scholarly gap in the existing literature, specifically the lack of research on Indigenous food system governance and limited research conducted in Sri Lanka. The study used two objectives in bridging the scholarly gap: 1) to synthesize the documented knowledge of Indigenous food system governance at a global-level and 2) to understand Indigenous food system governance at a local-level through a multi-sited case study in Sri Lanka. The study used a systematic literature review and a case study analysis of 'Vedda' communities to achieve these objectives. The systematic review included 143 peer-reviewed articles from the Web of Science and Scopus databases. Primary data gathered through fieldwork by conducting 114 semi-structured interviews with six partnered 'Vedda' communities were used in the multi-sited case study assessment. The study found how Indigenous food system governance varied globally, by identifying eight key definitive characteristics of Indigenous food system governance: co-management, leadership, research partnerships, collaborations, social networks, mutualism, collective action, and religious/cultural dimensions. The study found how identified global-level characteristics were applied at the local-level through Sri Lankan Indigenous case studies. The research suggests adopting governance methods that combine global guidelines (e.g., the rights of Indigenous peoples to maintain and strengthen their cultures and traditions) with local traditions to promote fair and sustainable food systems for Indigenous communities. This necessitates cooperation between worldwide organizations and local Indigenous peoples to guarantee that policies are both culturally sensitive and ecologically sustainable. Enabling Indigenous leaders to play a fundamental part in the planning and decision-making processes ensures that governance approaches are specifically adapted to the distinct food security needs of every community.
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    Least Cost Path Modeling Between Inka and Amazon Civilizations
    Lewis, Colleen Paige (Virginia Tech, 2022-06-09)
    Least Cost Path Analysis (LCPA) is a GIS-based approach for calculating the most efficient route between a start and end point, often in terms of shortest time or least amount of energy. The approach is often applied in archaeology to estimate locations of sites, and routes between them. We applied LCPA to estimate how sites in the Andes in the eastern portion of the Inka empire may have connected to sites in the western Amazon Basin. Our approach further used the known Inka Road network to test performance of two types of LCP models (linear vs. areal calculation) and four types of cost functions. LCPs can be calculated with an areal approach, where each cell of the DEM is given one overall slope value, or linearly, where the direction of travel across a cell affects the slope value. Four different algorithms were tested: Tobler's Hiking Function (1993), Tobler's Hiking Function with a vertical exaggeration of 2.3 based on human perceptions of slope (Pingel 2010), Pingel's empirical estimation approach (2010), and Pandolf et al.'s energy expenditure equation (1977) using both an areal and linear approach for all the algorithms. An initial study was conducted in the Cusco region and results were compared to the Inka Road network using the linear accuracy assessment method of Goodchild and Hunter (1997) and Güimil-Fariña and Parcero-Oubiña (2015). The findings suggest that the empirical estimation and caloric cost methods were the most accurate and performed similarly, both were more accurate than travel-time based costs, and linear methods were better than areal based methods when using higher resolution DEM inputs.
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    Patterns and Associations of Shoreline Erosion and Developed Land Use Change in the Lower Meghna Estuary of Bangladesh
    Huda, Nazmul (Virginia Tech, 2023-01-23)
    Population living along the coast are at risk of losing land, households, and economic resources due to the hazards of coastal erosion. Scientific research has indicated that 70% of the planet's sandy coastal environment is being impacted by coastal erosion. Due to the different characteristics of the lands in the coastal zone versus other areas, it is important to understand how the hazard of shoreline erosion contributes to subsequent land use change in affected coastal regions. This study analyzes how the level of erosion, land loss, and developed land loss performs when added with the default land use change parameters such as existing developed land proximity, proximity to forested areas, population, transportation, etc. Sample points of 1020 from 10 years and 15 years of shoreline erosion data for the lower Meghna River estuary of Southeast Bangladesh have been obtained and from there, different erosion statistics have been developed. Developed land use data has been collected from ESA's World Settlement Footprint dataset and other datasets are also collected from secondary data sources. Logistic regression modeling shows that there are verified contributions of proximity to erosion and amount of land loss with the probability of developed land use conversion in the study area. Adding the variables of environmental hazards increases the prediction accuracy by 2-3% and overall, the models are at least 85% accurate.
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    The Social Cascades of Exposure to Flood Induced Natech Events on Vulnerable Populations in Hampton Roads, Virginia
    Crawford, Margaret Calyer (Virginia Tech, 2022-05-31)
    Coastal flood impacts are increasing in severity with the rising sea levels, causing damage to ecological and human systems. Climate-hazards may also result in cascading impacts, where an initial disaster sets off a chain of events that extends beyond the initial spatiotemporal point of impact. Coastal flood events may result in consecutive disasters in which the initial flood event results in a secondary technological disaster, prompting disruptions to socio-economic systems and resulting in a public health crisis. Flood events that trigger technological emergencies through the inundation and dispersion of hazardous materials are known as Natech disasters. However, current research on the cascading impacts of Natech events is limited. Hampton Roads, Virginia, is experiencing an accelerated rate of sea level rise and a proportionally higher risk of storm surge, potentially leading to a greater risk of Natech disasters. The main objective of this study is to evaluate the impact of Natech events on surrounding communities in Hampton Roads. This study uses geospatial analysis to identify the current (2021) and future (2051) threats of flood-induced Natech disaster and assess its exposure to different coastal populations and ecosystems. The present study calculated the Flood Hazard Density Index (FHDI), using a 1-mile radius around the significantly flooded facilities to determine the spatial dispersion of Natech disasters. The flood risks were determined using the 100-year flood plain and intermediate (RCP 4.5) climate scenario. The risk of a Natech disaster was identified by combining the spatial extent of flood risk with the location of Toxics Release Inventory (TRI) facilities and National Priorities List (NPL) designated Superfund sites. The exposed environmental and social systems to Natech events were chosen through the literature gap analysis. Sociodemographic data from the American Community Survey were collected to examine its correlation with 2021 and 2051 FHDI-affected block groups. Findings reveal that block groups with higher proportions of minorities, people in poverty, and people without a vehicle experience significant exposure to a Natech disaster compared to those who are living further away from the TRI and Superfund facilities. Additionally, open water and wetland environments will also experience significant exposure to Natech events, which could indicate a loss of ecosystem services. This study suggests a need for proactive policy and programmatic interventions to minimize the potential impacts of Natech events on the surrounding communities, such as the remediation of Superfund sites and the development of hazard mitigation plans for TRI facilities.
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    Statistical and Machine Learning Models for Remote Sensing Data Mining — Recent Advancements
    Das, Monidipa; Ghosh, Soumya K.; Chowdary, Vemuri M.; Mitra, Pabitra; Rijal, Santosh (MDPI, 2022-04-15)
    During the last few decades, the remarkable progress in the field of satellite remote sensing (RS) technology has enabled us to capture coarse, moderate to high-resolution earth imagery on weekly, daily, and even hourly intervals [...]
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    Understanding perception of different urban thermal model visualizations
    Barua, Gunjan (Virginia Tech, 2023-03-17)
    While satellite-based remote sensing techniques are often used for studying and visualizing the urban heat island effect, they are limited in terms of resolution, view bias, and revisit times. In comparison, modern UAVs equipped with infrared sensors allow very fine-scale (cm) data to be collected over smaller areas and can provide the means for a full 3D thermal reconstruction over limited spatial extents. Irrespective of the data collection method, the thermal properties of cities are typically visually represented using color, although the choice of colormap varies widely. Previous cartographic research has demonstrated that colormap and other cartographic choices affect people's understanding. This research study examines the difference in map reading performance between satellite and drone-sourced thermal pseudo-color images for three map reading tasks, the impact of color map selection on map reading, and the potential benefits of adding shading to thermal maps using high-resolution digital surface models for improved interaction. Participants expressed a preference for the newly designed rainbow-style color map "turbo" and the FLIR "ironbow" colormap. However, user preferences were not strongly related to map reading performance, and differences were partly explained by the extra information afforded by multi-hue and shading-enhanced images.