Increased stormwater runoff due to urban development in the northern Shenandoah Valley (NSV) region of Virginia has prompted local officials and representatives to consider Low Impact Development (LID) as a stormwater management technique. LID is based on infiltrating stormwater runoff at the source through practices such as bioretention, rain gardens, and grass swales. The karst terrain that underlies the Shenandoah Valley presents a major barrier to the use of LID. Infiltration of surface runoff in karst landscapes may threaten groundwater quality and the stability of the bedrock. In 2004 the Center for Geospatial Information Technology (CGIT) at Virginia Tech developed an LID site suitability model for the NSV region incorporating karst as a key component in distinguishing unsuitable from suitable conditions for LID. But, due to the difficulty of mapping karst, the karst layer used in the site suitability model is very coarse in resolution, based primarily on carbonate versus non-carbonate rock. This study uses a 1:24,000 scale sinkhole map derived from sinkhole boundaries identified by geologist David Hubbard (1984) of the Virginia Department of Mines and Minerals (DMME) to develop a more detailed karst map for a sub-watershed of the NSV region. The analysis uses geospatial techniques to determine the relationship between sinkhole distribution and four major landscape factors: bedrock type, soil depth to bedrock, proximity to geologic faults, and proximity to surface streams. The analysis identified three major trends in sinkhole occurrence: (1) sinkholes are more abundant in relatively pure carbonate rocks of Ordivician age; (2) sinkhole occurrence increases with proximity to fault lines; and (3) sinkholes are sparse near streams, most abundant 600 to 1400 feet away from surface streams. Based on these findings a sinkhole susceptibility index was produced using weighted overlay analysis in ArcGIS. The sinkhole susceptibility index provides a more detailed karst layer for the LID site suitability maps and can be used by the NSV region as a predictive tool for future sinkhole occurrence. / Master of Science

In the territory of the Gwich’in First Nation, in Canada’s Northwest Territories, environmental, sociocultural, and economic changes are affecting relationships between communities and the land and water. In this thesis, I used two research projects to explore the impacts of social-ecological change in Gwich’in territory by examining cumulative impacts in the cultural landscape, and determinants of access to fish and well-being. In the first part of my MA, I used spatial overlay analysis to quantify and map: 1) cultural feature intensity, 2) cumulative environmental disturbance, and 3) overlap between disturbances and cultural features. I also interviewed four regional cultural heritage experts, who contributed critical insights into representing Gwich’in cultural features. The first two analyses indicated that overlay methods can facilitate understandings of land use and cumulative impacts, illustrating Gwich’in territory as a cultural landscape encompassing widespread, dense cultural features and diffuse, lower intensity cumulative environmental impacts. The third analysis showed that overlaying cultural feature and disturbance data is a novel, straightforward step to better incorporating cultural impacts in cumulative impact assessments. Many of the changes I mapped are affecting fishing practices central to Gwich’in livelihoods. To better understand these changes, in the second part of my MA I explored the relationship between drivers of access to fish and well-being amidst social-ecological change, by interviewing 29 Gwich’in individuals. My interviews showed that socioeconomic and environmental barriers have decreased access to fish. However, access to fish remains critical and related to well-being, driven by various socioeconomic factors. Many of these factors are reflected in sharing networks and adaptive practices that are encompassed in ecological monitoring and land-based education. These factors may strengthen Gwich’in fishing livelihoods, and highlight the importance of programs like the Rat River Char Monitoring program, and land-based education like the Ganahghootr’onatan – Teetł’it Land Based Learning Project. / Graduate

<p>Floods are common natural disaster occurring in most parts of the world. This results in damage to human life and deterioration of environment. There have been immense uses of technology to mitigate measures of flood disaster i.e. structurally and non-structurally. Undoubtedly, structural measures are very expensive and time consuming which involves physical work like construction of dams, reservoirs, bridges, channel improvement, river diversion and other embankments to keep floods away from people. Whereas non-structural measures is concerned with planning like flood forecasting and warning, flood plain zoning, relief and rehabilitation for reducing the risk of flood damage to keep people away from floods. Thus, non-structural measures involve analysis, planning providing spatial information on maps with high accuracy in less time. Non-structural measures can help decision maker to plan an effective emergency response towards flood disaster. A one of the good way to plan non-structural measures is to analyze impact of flood in the flood prone areas. The thesis tries to analyze impact of flood on environment along the demarcated flood prone areas of Lake Roxen and Lake Glan in Östergötland County, Sweden. The thesis also proposes how to use current flood information during flood emergency utilizing geographical information system. This provides spatial information for area in the flood zone for assessment regarding flood vulnerability.</p><p>Using map overlay analysis in GIS software (ArcGIS); flood prone areas and topographic data along Lake Roxen and Lake Glan were digitized from PDF maps. Thus, the thesis work is an effort to analyze impact of flood when areas along Lake Roxen and Lake Glan are flooded. ESRI® GIS software Arc Map 9 and Arc View 3.3 is used for data preparation, integrating, analyzing, and spatial data with attribute table information. Finally, to show GIS can be an effective tool for development of flood emergency system as a part of disaster preparedness by the decision makers.</p>

Floods are common natural disaster occurring in most parts of the world. This results in damage to human life and deterioration of environment. There have been immense uses of technology to mitigate measures of flood disaster i.e. structurally and non-structurally. Undoubtedly, structural measures are very expensive and time consuming which involves physical work like construction of dams, reservoirs, bridges, channel improvement, river diversion and other embankments to keep floods away from people. Whereas non-structural measures is concerned with planning like flood forecasting and warning, flood plain zoning, relief and rehabilitation for reducing the risk of flood damage to keep people away from floods. Thus, non-structural measures involve analysis, planning providing spatial information on maps with high accuracy in less time. Non-structural measures can help decision maker to plan an effective emergency response towards flood disaster. A one of the good way to plan non-structural measures is to analyze impact of flood in the flood prone areas. The thesis tries to analyze impact of flood on environment along the demarcated flood prone areas of Lake Roxen and Lake Glan in Östergötland County, Sweden. The thesis also proposes how to use current flood information during flood emergency utilizing geographical information system. This provides spatial information for area in the flood zone for assessment regarding flood vulnerability. Using map overlay analysis in GIS software (ArcGIS); flood prone areas and topographic data along Lake Roxen and Lake Glan were digitized from PDF maps. Thus, the thesis work is an effort to analyze impact of flood when areas along Lake Roxen and Lake Glan are flooded. ESRI® GIS software Arc Map 9 and Arc View 3.3 is used for data preparation, integrating, analyzing, and spatial data with attribute table information. Finally, to show GIS can be an effective tool for development of flood emergency system as a part of disaster preparedness by the decision makers.