Evaluating Aggregate Terrestrial Impacts of Road Construction Projects for Advanced Regional Mitigation

Abstract

This study presents a GIS-based database framework used to assess aggregate terrestrial habitat impacts from multiple highway construction projects in California, USA. Transportation planners need such impact assessment tools to effectively address additive biological mitigation obligations. Such assessments can reduce costly delays due to protracted environmental review. This project incorporated the best available statewide natural resource data into early project planning and preliminary environmental assessments for single and multiple highway construction projects, and provides an assessment of the 10-year state-wide mitigation obligations for the California Department of Transportation. Incorporation of these assessments will facilitate early and more strategic identification of mitigation opportunities, for single-project and regional mitigation efforts. The data architecture format uses eight spatial scales: six nested watersheds, counties, and transportation planning districts, which were intersected. This resulted in 8058 map planning units statewide, which were used to summarize all subsequent analyses. Range maps and georeferenced locations of federally and state-listed plants and animals and a 55-class landcover map were spatially intersected with the planning units and the buffered spatial footprint of 967 funded projects. Projected impacts were summarized and output to the database. Queries written in the database can sum expected impacts and provide summaries by individual construction project, or by watershed, county, transportation district or highway. The data architecture allows easy incorporation of new information and results in a tool usable without GIS by a wide variety of agency biologists and planners. The data architecture format would be useful for other types of regional planning.

Fragmentation of China’s landscape by roads and urban areas

“…While naturally occurring fragmentation can result in greater biodiversity (Quinn and Harrison 1988), habitat fragmentation from human land-uses can threaten plant biodiversity (Honnay and Jacquuemyn 2007) biodiversity in general (Fahrig 2003), and genetic flows (Hilty et al 2007). Landscape fragmentation by roads, urban construction and other human activities is widely studied outside of China (Forman et al 2003;Coffin 2006;Shilling 2007;Shilling and Girvetz 2007;Watts et al 2007;Girvetz et al 2008;Thorne et al 2009) and has been used to evaluate human impacts on ecosystem integrity at a landscape scale. Large habitat patches are important to many species (Collinge 1996) and connectivity within and among patches is an important landscape function permitting ecological flows (Beier and Noss 1998).…”

The use of regional advance mitigation planning (RAMP) to integrate transportation infrastructure impacts with sustainability; a perspective from the USA

“…The second buffer is the distance from the edge of the inner buffer to the edge of the new project, which is the zone of new impact that different types of projects (e.g. adding highway lanes) will occupy when constructed (Thorne et al 2009a). The inner area was then buffered by the second distance to arrive at a total project footprint (e.g.…”

“…However, transportation structures have adverse impacts to the natural environment (Trombulak and Frissell 2000, Forman et al 2003, National Research Council 2005, including: direct and cumulative mortality to species hit by vehicles (Seo et al 2013), reduced dispersal capacity (Forman and Alexander 1998), impediments to gene flow (Epps et al 2005), the spread of invasive species (Gelbard and Belnap 2003), the generation of greenhouse gas emissions (Fuglesvedt et al 2008, Kennedy et al 2009, and landscape fragmentation (Jaeger et al 2005, Girvetz et al 2008. Concern over the rapid growth of cities and transportation infrastructure highlights the need to reduce environmental impacts associated with this growth (Thorne et al 2005(Thorne et al , 2009a by initiating or improving requirements to offset those impacts via conservation or restoration of other lands, here termed environmental mitigation.…”

“…As a framework, RAMP engages multiple parties, including transportation infrastructure developers (governmental or private), government agencies that enforce environmental laws, and research and environmental groups that have identified critical lands for conservation. This cooperation between multiple stakeholders permits the incorporation of planning principles and environmental considerations early in the development of transportation infrastructure and other construction plans and projects (Thorne et al 2009a(Thorne et al , 2009b.…”

An Approach to Enhance the Conservation-Compatibility of Solar Energy Development

“…Finding areas that are both suitable for renewable energy development and of relatively low biodiversity conservation value represents a possible “win-win” for two otherwise potentially conflicting objectives [19]. When complete avoidance of impacts is not possible, this approach can improve the conservation return of investments in compensatory mitigation, by directing it to places and efforts that also advance regional conservation goals [16], [20], [21].…”