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Pedestrian Path Generation through GPS Traces
Published in Hassan A. Karimi, Advanced Location-Based Technologies and Services, 2016
Piyawan Kasemsuppakorn, Hassan A. Karimi
A pedestrian is “any person who is afoot or who is using a wheelchair or a means of conveyance propelled by human power other than a bicycle” (Washington State Legislature 2003). We call any pathway that is designed for pedestrians as a pedestrian path segment, whose purpose is to improve pedestrian safety, reduce potential accidents, and promote mobility and accessibility. We distinguish between seven different types of pedestrian path segments: sidewalk, pedestrian walkway or footpath, accessible entrance, crosswalk, pedestrian bridge, pedestrian tunnel, and trail (Kasemsuppakorn and Karimi 2009a). A sidewalk is the most general structure that is designed for pedestrian traffic alongside a road. A pedestrian walkway, or footpath, is a path that is not along the side of a road such as a walkway between buildings or a footpath to a plaza. A building entrance is a part of a pedestrian walkway, but it is specifically at the entrance of the building. The following three types are related to crossing a street. Crosswalk is a facility that is marked on a road indicating the part of the road which pedestrians should use for crossing the road. The grade-separated crossings are built structures that assist pedestrians to cross areas unnavigable by a simple crosswalk because the terrain is too dangerous or inconvenient to travel. A pedestrian bridge is constructed over a roadway, whereas a pedestrian tunnel is an underground passageway. A trail is mostly designed for recreational activities such as running trails or natural trails.
Characterizing Tropical Forests with Multispectral Imagery
Published in Prasad S. Thenkabail, Land Resources Monitoring, Modeling, and Mapping with Remote Sensing, 2015
E.H. Helmer, Nicholas R. Goodwin, Valéry Gond, Carlos M. Souza, Jr., Gregory P. Asner
14.5.4.1.1 Road and Trail Detection Road and trail detection is also a challenge for tropical forest management. Opening, active, and abandoned road and trail networks are a permanent landmark of tropical forest openness and degradation (Laurance et al., 2009). Documenting this dynamic is possible with the 30 years of medium-resolution radiometer archives (Landsat and SPOT). In 2007, Laporte et al. (2007) photo-interpreted Landsat imagery to map the road and trail network across the forests of Central Africa to show which forest areas are endangered by logging activity. When displaying red, NIR, and SWIR channels in red, green, and blue, active roads and trails are “brown”; abandoned roads and trails are “green,” and intact tropical forests are “dark green” (de et al., 2004). To automatically process the archives for large areas, Bourbier et al. (2013) proposed a method for using Landsat archive to allow tropical forest managers to visualize the road and trail network dynamism at local (concession) or national scales.
Forestry best management practices and modeled erosion on planned and logger-selected bladed skid trails in the Ridge and Valley region, Virginia, USA
Published in International Journal of Forest Engineering, 2019
Robert Howell, Wallace Michael Aust, M. Chad Bolding
Virginia BMPs recommend that bladed skid trail grades be less than 25%, with grade breaks and proper drainage (VDOF 2011). Post-harvest closure BMPs essentially determine long-term erosion rates and sedimentation. Erosion rates tend to be highest just after post-harvest closure and decrease afterwards (Wynn et al. 2000; Vinson et al. 2017a, 2017b). Closure practices include restricting forest skid trail traffic, installing water and erosion control structures on haul roads and skid trails, resurfacing roads to channel water from the trail surfaces, removing temporary stream crossings, and providing cover for bare soil surfaces (Virginia Department of Forestry (VDOF) 2011). BMP structures for water control include water bars, wing ditches, brush/straw barriers, rolling dips, and some combination of such water control structures are required for minimizing water volumes and velocities carried on skid trail surfaces (Masumian et al. 2017). Common ground coverage techniques include seed, straw mulch, and applying forest slash. Straw mulch and slash have proven most effective at reducing erosion rates due to immediate ground coverage (Sawyers et al. 2012; Wade et al. 2012; Vinson et al. 2017a). Skid trails should be located outside of Streamside Management Zones (SMZs) and appropriate BMPs should be implemented on stream crossings approaches (Lakel et al. 2010; Lang et al. 2015).
Watershed management and underlying geology in three lakes control divergent responses to decreasing acid precipitation
Published in Inland Waters, 2018
David C. Richardson, David M. Charifson, Bobbetta A. Davis, Matthew J. Farragher, Bryan S. Krebs, Elizabeth C. Long, Megan Napoli, Brian A. Wilcove
Four types of gravel were identified by the Minnewaska State Park Preserve management as commonly applied to trails in the State Park Preserve. The trail surrounding Minnewaska is between 7 and 170 m of the lake edge. Some trails extend into the Awosting watershed, but the trails are predominantly native bedrock and soil substrate. For Minnewaska State Park Preserve, 4 types of gravel were used for trails: 3 purchased from external suppliers and one mined locally on site (Minnewaska State Park Preserve, pers. comm.). A gravel mix (R1) was used by an outside contractor when modifying the trails. Item 4 (R2) was a silty shale gravel from the Mt. Marion formation (A. Bartholomew, Geology Department, SUNY New Paltz, 2013, pers. comm.). Shale (R3) was mined about 2.4 km from Minnewaska and was from the Pen Argyl member of the Martinsburg formation also exposed under Mohonk. This shale has been used to line trails around Minnewaska for >50 years. A mix purchased from offsite (R4) contained several types of rock, including limestone as indicated by bubbles released during a simple acid test for carbonate rocks via application of hydrochloric acid. All 4 types combined represented a mixture used on the 3.2 km trail loop around Minnewaska, the parking lot, and elsewhere in the park in 2013. We collected all gravel from the park’s onsite storage areas prior to their application on the trails.