Filters: Tags: Road density (X)
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Road features were identified using TIGER line data and those features mapped as freeways, secondary roads and local roads were selected. A moving window analysis was applied, which used a window area of 640 acres to determine the miles of road per 640 acres. Output from the analysis was scored where road density values less than 3 miles/640acres were scored as a 3 (“preferred”) and road density values greater than 3 miles/640acres received a score of 1 (“lower quality”).
Conclusions: Caribou subpopulation persistence and landscape occupancy depends highly on the degree of forest cover, cover type, and distance from human presence. Thresholds/Learnings: Synopsis: This study evaluates factors influencing the persistence and landscape occupancy of caribou subpopulations in southern British Columbia. Data from 235 radio-collared caribou across 13 subpopulations were used to derive a landscape occupancy index. The index was analyzed against 33 landscape variables including, land cover, terrain, climate, and human influence. At the metapopulation level, the persistence of subpopulations correlated with the extent of wet climate conditions and the distribution of old forests and alpine...
Categories: Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: British Columbia,
Columbia Mountains/Northern Rockies,
Extirpation,
Forest,
Fragmentation,
Image of lenth of roads per 1 km-square pixel, derived from streets and roads layers of Census Bureau TIGER 98 files. Pixel values are sum lengths of streets and major roads (including interstate highways) in units of meters. For more information about the TIGER files see the following url: http://www.census.gov/geo/www/tiger/
Tags: road density,
roads
This dataset depicts indices of forest fragmentation within the U.S. Northeast region. This dataset can help inform prioritization of landscapes for conservation through identification of more intact forested areas. Forest fragmentation was assessed using information derived from the National Land Cover Dataset (NLCD) and USGS 1:100,000 scale roads. Within each forested ecoregion in the World Wildlife Fund ecoregions dataset, landscape units (land units) were defined using U.S. Census Bureau TIGER highway networks. Land units were blocks of forested land bounded by highways and were required to be at least 2,000 hectares in size. Land units smaller than 2,000 hectares or areas within urban areas were excluded from...
Road densities derived from the TIGER data were analyzed to determine the relationship between road density and Bald eagle potential suitable habitat. The quality of a HUC in relation to road density was defined as good (3), fair (2), or poor (1). The score indicates the threat level for each attribute. A low score indicates a low threat, a medium score indicates a medium threat, and a high score indicates a high threat to the species. The values for each score were characterized in relation to road density by >10 km/km2 = good, 5-10 km/km2 = fair, and 2 = poor.
This tabular data set represents select basin characteristics compiled for two spatial components of the NHDPlus version 2 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. The select variables in this data set are parsed out into six different file themes as follows: BASIN_CHAR_XXX_CONUS.txt (where XXX is CAT flowline catchment value, ACC is divergence routed accumulated value, and TOT is total upstream routed accumulated value) contains information on stream slope (percent rise, also referred to as the percent slope), basin slope (percent rise, also referred to as the percent slope), basin area, minimum...
This road density dataset can inform the Clearwater Basin Collaborative about where to establish "working areas" of more active timber management across the Basin.
The 2000 Rogue River aquatic integrity analysis used road density, road-stream intersections, forest change and fish barriers as surrogate indicators of watershed integrity. High road density contributes to increased levels of erosion and sedimentation and consequent alterations to hydrological patterns and degradation of water quality (OCSRI 1997). In addition, watersheds with higher road densities provide easier human access and are correlated with higher levels of disturbances from human activities that degrade water quality and aquatic habitat integrity (Frissell et al. 1996, Roth et al. 1996).
Road features were identified using TIGER line data and those features mapped as freeways, secondary roads and local roads were selected. A moving window analysis was applied, which used a window area of a square kilometer to determine kilometers of road per square kilometer. Output from the analysis was scored based on the following criteria where road density values less than 0.18km/km2 were scored as a 3 (“preferred”), densities between .18 and 1.0518 km/km2 scored as a 2, and road density values greater than 1.0518km/km2 received a score of 1 (“lower quality”)
Road density can inform "working areas" of more intensive harvest activities within the Clearwater Basin Collaborative
Simple road density calculated as miles of road per square mile. Thus, a 1 square mile circular window was used to sum the length of road for each 30 meter cell. I relied only on Clearwater and Nez Perce National Forest roads datasets.
Conclusions: Report describes the development of a multi-metric, fish-based Index of Biological Integrity (IBI) to assess the health of aquatic ecosystems on the Battle River, Alberta. The IBI was highly sensitive to cumulative anthropogenic disturbance. Impaired integrity of fish assemblages was detectable at road densities as low as 0.7km/km2 Thresholds/Learnings: Impaired integrity of fish assemblages was detectable at road densities as low as 0.7km/km2. Synopsis: Report describes the development of a multi-metric, fish-based Index of Biological Integrity (IBI) to assess the health of aquatic ecosystems on the Battle River, Alberta. The IBI was highly sensitive to cumulative anthropogenic disturbance. Impaired...
Categories: Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Alberta (Central),
Battle River,
IBI,
Index of Biological Integrity (IBI),
Land use configuration,
This road density dataset can inform "working areas" that are appropriate for more active timber harvest according to the Clearwater Basin Collaborative
We attempted a complete review of the empirical literature on effects of roads and traffic on animal abundance and distribution. We found 79 studies, with results for 131 species and 30 species groups. Overall, the number of documented negative effects of roads on animal abundance outnumbered the number of positive effects by a factor of 5; 114 responses were negative, 22 were positive, and 56 showed no effect. Amphibians and reptiles tended to show negative effects. Birds showed mainly negative or no effects, with a few positive effects for some small birds and for vultures. Small mammals generally showed either positive effects or no effect, mid-sized mammals showed either negative effects or no effect, and large...
Categories: Publication;
Types: Citation;
Tags: environmental impact,
landscape connectivity,
mortality,
population density,
road density,
Low Road Density This layer is one of the South Atlantic LCC indicators in the landscapes “habitat aggregate”, which is intended to capture connections across all terrestrial ecosystems. It is an index of areas with few roads. Reason for Selection Large areas with few roads are favorable for conservation of numerous species, including reptiles and amphibians, birds, and large mammals. Roads can cause negative impacts by promoting dispersal of invasive species and inhibiting water flow. Road density, as well as urban expansion in areas of low road density, are straightforward to measure and monitor. Road density has been used in other broad-scale conservation planning efforts and is widely used and understood by...
Categories: Data;
Types: ArcGIS REST Map Service,
ArcGIS Service Definition,
Downloadable,
Map Service;
Tags: Forested Wetland,
Priority Amphibian and Reptile Conservation Areas,
amphibians,
reptiles,
road density
Conclusions: Reduction in landscape carrying capacity for wolf population distribution and viability depends largely on the degree of road density, public land ownership, amount of forest cover and high elk densities (another indicator of suitable habitat). Synopsis: This study employed two types of spatial models to evaluate the potential of wolf reintroduction in the southern Rocky Mountain region. A multiple logistic regression was used to develop a resource-selection function relating wolf distribution in the Greater Yellowstone region with regional-scale habitat variables. Researchers also used a spatially explicit population model to predict wolf distribution and viability at several potential reintroduction...
Categories: Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Colorado,
Dynamic models,
Land use configuration,
Landscape fragmentation,
New Mexico,
Conclusions: Habitat associations of prairie rattlesnakes appear to differ depending on whether snakes are hibernating, foraging, or reproducing. Most rattlesnake hibernacula occur within 4 km of a major river, drainage, or coulee, on relatively gentle slopes, but they migrate as far as 25 km away from dens in summer. High road densities present unfavorable habitat conditions for snakes because they are a significant cause of mortality. *Note that this study generated landscape level models with coarse variables, and the thresholds and values used may not be directly applicable to other areas or for site-specific analysis. Thresholds: Most rattlesnake hibernacula occur within 4 km of a major river, drainage, or...
Categories: Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Alberta,
Land use configuration,
Landscape fragmentation,
Natural cover amount,
prairie,
Conclusions:The occurence of bull trout in mid-boreal stream is negatively related to two metrics of industrial activity: percent forest harvesting and road density. Bull trout abundance was positively related to elevation, and negatively related to stream width, slope, and levels of forest harvesting.Thresholds/Learnings:Timber harvest on up to 35% or more of individual subbasins is projected to result in the extripation of bull trout from up to 43% of stream reaches, especially those that support high densities of bull trout.
Categories: Publication;
Types: Citation;
Tags: Land use configuration,
Landscape fragmentation,
Natural cover amount,
Western Alberta,
boreal forest,
Road densities derived from the TIGER data were analyzed to determine the relationship between road density and Bald eagle potential suitable habitat. The quality of a HUC in relation to road density was defined as good (3), fair (2), or poor (1). The score indicates the threat level for each attribute. A low score indicates a low threat, a medium score indicates a medium threat, and a high score indicates a high threat to the species. The values for each score were characterized in relation to road density by >10 km/km2 = good, 5-10 km/km2 = fair, and 2 = poor.
Conclusions: Results offer support for the use of land cover as an indicator of biotic integrity estimated by both vegetation and bird communities. Strong, significant predictions of IBI scores in plant and bird communities were achieved using land cover data from every spatial extent. Plant-based IBI scores were best predicted using data from 100 m buffers and bird-based IBI scores were best predicted using data extracted from 500 m buffers. Road density and measures of the proportion of disturbed land were consistent predictors of IBI score, suggesting their universal importance to plant and bird communities. Thresholds/Learnings: Road effects on bird communities were most pronounced at the 500m spatial extent....
Categories: Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Alberta,
IBI,
Natural cover amount,
Wetland assessment,
biodiversity,
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