• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • Tagged with
  • 7
  • 7
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Evaluating the Effectiveness of Wildlife Crossing Structures in Southern Vermont

Bellis, Mark 01 January 2008 (has links) (PDF)
Roads are prominent, contiguous features covering approximately 1% of the United States land mass and have been built for decades with little consideration for ecological effects. Increasingly, the impacts of roads are being recognized and the science of road ecology is emerging as an important area of study for conservation biologists. For wildlife, the impacts of roads are disproportionate to the area of land they occupy. Direct impacts on wildlife include mortality via vehicle collision and restriction or alteration of movement. Road kill exceeds hunting as the leading direct human cause of vertebrate mortality, with approximately one million vertebrates a day killed on roads in the United States. Roadways also affect wildlife through habitat loss and fragmentation, isolation of wildlife populations, disruption of gene flow and metapopulation dynamics. A variety of strategies have been used with mixed success to mitigate the impacts of roads on wildlife. Commonly, underpasses are used to facilitate movement of wildlife across roadways in Europe, Australia, Canada and the U.S.. However, the effectiveness of these underpasses to facilitate wildlife movement depends on a number of variables, including: size, proximity to natural wildlife corridors, noise levels, substrate, vegetative cover, moisture, temperature, light, and human disturbance. Further, different species typically have different requirements. Thus if crossing structures are designed for use by a singles species, they may constitute an absolute barrier for other species that have different requirements. Most attempts to evaluate wildlife crossing structures focus exclusively on documenting wildlife use of structures. While tracking beds, cameras, and counters document the species using structures, they provide little information on those species or individuals that fail to use a structure. In contrast, telemetry, trapping and tracking studies are more useful for determining the extent to which roadways inhibit wildlife movements and the degree to which crossing structures mitigate these effects. Thus, to fully assess the effectiveness of wildlife passageways, a combination of monitoring techniques across a variety of taxa is needed to evaluate structure use impacts of transportation systems on animal movements. The goal of this study was to assess the effectiveness of wildlife crossing structures constructed as part of the Bennington Bypass (Highway 279) in southern Vermont. The bypass was completed in October 2004 and includes three wildlife crossing structures, including two extended bridges and a large culvert. This study monitored the effectiveness of these crossing structures and compared rates of wildlife movement across the highway in mitigated and unmitigated sections.
2

Experimental Tests of Road Passage Systems for Reducing Road Mortalities of Freshwater Turtles

Yorks, Derek T 18 March 2015 (has links)
Roadways are a pervasive feature of northeastern landscapes and can be a significant source of mortality for turtles. Until recently, little has been known about the design requirements for successful under-road passages for turtles and other wildlife to move safely between bisected habitat patches. At outdoor laboratories, using a factorial experimental design, we examined movements in response to varying light levels, and barrier opacity for painted turtles (Chrysemys picta, n=833), Blanding’s turtles (Emydoidea blandingii, n=49), and spotted turtles (Clemmys guttata, n=49). Additionally, we examined tunnel size, tunnel entrance design, and artificial lighting for painted turtles only. All three species responded poorly to a 0% available light treatment. As the amount of natural light transmitted through the tops of tunnels increased, successful completion of the trials increased. Furthermore, turtles generally moved at a slower rate when traveling along a translucent barrier, compared to an opaque one. Our results indicate the importance of designing road passage structures for freshwater turtles that provide adequate tunnel lighting in combination with specific entrance designs that meet the goals of the project.
3

Spatial Modeling of Wildlife Crossing:GIS-based Approach for Identifying High-priority Locations of Defragmentation across Transport Corridors / Rumslig Modellering av Ekodukt: GIS-baserad Modellering för att identifiera Habitat Flaskhalsar Längst en Transport Korridor.

Jonsson, Josefine January 2017 (has links)
In this report, connectivity modeling has been performed using land cover data to find habitat pinch-points for deer along the study area Norrortsleden in Stockholm. Norrortsleden was chosen because there are a high number of deer accidents in the area, and is a priority area for action according to a barrier analysis for deer made by the Swedish Transport Administration. After interviews and research, it was found that a tool named LinkageMapper using CircuitScape theory is one good way to find habitat pinch-points along transport corridors. Firstly, a habitat resistance raster map and zone data are needed. The habitat resistance layer was made using ground cover data and given resistance values specifically for deer. An edge-zone layer was also added on top using built-in ArcGIS tools. Lastly all the road and railway data was transformed into raster and added to the final resistance layer. To find the pinch-points in the natural habitat for deer, different settings for the ArcGIS tool LinkageMapper have been tested and variations of the zone layer have been used. LinkageMapper is an external free to download tool and uses CircuitScape theory to find habitat pinch points. Different settings were tested for a 2-zone version on a 2 km buffer on each side of the road. In addition, two main settings are available, all-to-one mode and pairwise mode in LinkageMapper. Input width must also be entered to limit the number of results. Corridor width was set to 50 m for all of the produced results. After preparation of the raw data, processing zones and resistance layers it was found that usually only one corridor was showing, so a version with 6 zones on each side of the road with a 4 km buffer was made and produced more continuous results. All of the pinch-points found were marked on a map and the ones not already near an existing wildlife passage are located just south of Lake Vallentuna. The research found that the GIS-based approach is effective for Identifying high-priority locations of defragmentation across transport corridors. Using CircuitScape theory can be a great compliment too regular least cost-path.
4

The use of spatial and temporal analysis in the maintenance of road mortality mitigation measures for wildlife in Ireland

Moroney, Aoife January 2018 (has links)
Urbanisation and a growing global population have caused our road networks to expand rapidly in the past decades. The consequences of transport infrastructure for wildlife include traffic mortality, habitat loss and habitat degradation and the negative impact of a road extends far beyond the road itself. In Ireland, there are mitigation measures for wildlife mortality in place on all major roads. Mitigation measures can help reduce wildlife-vehicle collisions and increase habitat connectivity but need to be properly monitored and maintained following implementation. This study was carried out in collaboration with the Environmental Policy & Compliance department at Transport Infrastructure Ireland (TII), a state agency in Ireland responsible for national road and public transport infrastructure. It applied various spatial and temporal analyses methods in order to ascertain how best to prioritise critical road sections and times for maintenance. The significance of the study is that recent site visits carried out in Ireland found that 66% of mitigation measures were of inadequate standard. The methods were applied to roadkill data taken over an eight year period on the M3 motorway in county Meath, Ireland. This case study was chosen as mitigation measures, such as underpasses and mammal underpasses, have been in operation since its’ opening in 2010. It was found that temporal analysis could provide an insight into whether roadkill was increasing or decreasing annually as well as what months were most recommendable to carry out maintenance. The spatial analysis began with using Ripley’s K-statistics to first determine whether or not clustering of roadkill was occurring along the study area. Four different methods of locating hotspots along a road network were then applied and compared; Malo’s method, 2D Hotspot Analysis using Siriema Road Mortality software, kernel density estimation using SANET and finally KDE+. The findings showed that, despite mitigation measures being in place, hotspots were still occurring indicating road sections experiencing higher numbers of roadkill than expected in a random situation. These sections could then be prioritised for maintenance. It was found that the KDE+ software in conjunction with the use of a roadkill data app was the most recommendable approach. It was also noted that that the app should be expanded to other road classes and rail. It is recommended that this be made a standard protocol, comparable on a national level, for the prioritisation of mitigation measures for maintenance. Finally, it was recommended that more public awareness about wildlife-vehicle collisions and mitigation measures be raised. In the future, the app could also be connected to GPS systems to warn drivers of critical road sections. If these methods and recommendations are applied to the Irish road network, a reduction in roadkill should be observed.
5

Ecological Infrastructure: A Framework for Planning and Design: "Addressing Landscape Connectivity and Wildlife Resources for Interstate Highway Systems"

Baker, John Garrett 06 July 2005 (has links)
For the last century, automobiles and the roads they require have been a dominant force shaping the modern American landscape. An unrivaled interstate highway system connects major metropolitan areas and is the basis of our transportation infrastructure. Unfortunately, many roadways were not planned or designed with wildlife in mind. As long linear features in the landscape, interstates can function as landscape barriers and cause significant impacts to adjacent wildlife populations. While an aggressive transportation system is being carried out, researchers have only marginally demonstrated the relationships between roadways and wildlife. In such cases, twinned interstate roadways have proven to be the greatest obstacle for wildlife resources. By incorporating ecological design theory into highway planning and design, the transportation community has an opportunity to reassess the short comings of existing highway infrastructure and improve functions of wildlife passage and landscape connectivity. Through system level approaches and analysis applied within an eco-region context, practical solutions can be developed. The following document provides a process for landscape level analysis, wildlife passage structure design and implementation for future planned interstates projects. As a collaborative effort among professionals, we can work towards improving interstate highway systems and retain the relationships occurring within the landscape. The following I-81 design and planning project offers an exceptional opportunity to reassess the inadequacies of the existing interstate infrastructure in terms of landscape connectivity, wildlife resources and public safety, and demonstrate how system level design approaches can give our roadways new shape and form. / Master of Landscape Architecture
6

The Rocky Reality of Roadways and Timber Rattlesnakes (Crotalus horridus): An Intersection of Spatial, Thermal, and Road Ecology

Sisson, Garrett P. 19 September 2017 (has links)
No description available.
7

Potential value extraction from TxDOT’s right of way and other property assets

Paes, Thiago Mesquita 16 February 2012 (has links)
Many Departments of Transportation (DOTs), including Texas Department of Transportation (TxDOT), have been challenged by inadequate funding from traditional federal and state fuel taxes, increasing construction cost, aging highway system, traffic congestions, and recent natural disasters, compromising their primary mission to provide safe vehicle transportation routes with adequate capacity. Furthermore, environmental awareness and sustainability concept have strengthened and sparked debates in Congress, culminating with several regulatory policies that affect, inclusively, transportation projects. This scenario has prompted DOTs to pursue innovative ways to reduce maintenance cost (at minimum) and generate revenue (at maximum) exploiting their assets, and to meet the new regulations. Likewise, the Center of Transportation Research at The University of Texas at Austin undertook a comprehensive research study to identify and determine when, where, and under what circumstances TxDOT should pursue the implementation of which Value Extraction Application (VEA), and how to effectively recognize and involve key stakeholders. As a result, 11 VEAs were identified. In addition, a methodological framework – embedding a multi-attribute criteria analysis matrix as the decision making method - was devised to guide TxDOT throughout the process of identifying, evaluating, comparing, and selecting the most appropriate VEA while a list of stakeholders associated with each VEA and a stakeholder analysis framework was provided to help TxDOT to identify and reach out key stakeholders. / text

Page generated in 0.0442 seconds