Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, UK.
UK Centre for Ecology and Hydrology, Maclean Building, Wallingford, Oxfordshire OX10 8BB, UK.
Sci Total Environ. 2021 Jun 15;773:145589. doi: 10.1016/j.scitotenv.2021.145589. Epub 2021 Feb 6.
Roads form vast, pervasive and growing networks across the Earth, causing negative environmental impacts that spill out into a 'road-effect zone'. Previous research has estimated the regional and global extent of these zones using arbitrary distances, ignoring the spatial distribution and distance-dependent attenuation of different forms of road environmental impact. With Great Britain as a study area, we used mapping of roads and realistic estimates of how pollution levels decay with distance to project the spatial distribution of road pollution. We found that 25% of land was less than 79 m from a road, 50% of land was less than 216 m and 75% of land was less than 527 m. Roadless areas were scarce, and confined almost exclusively to the uplands (mean elevation 391 m), with only ca 12% of land in Great Britain more than 1 km from roads and <4% of land more than 2.5 km from roads. Using light, noise, heavy metals, NO, and particulate matter PM and PM as examples, we estimate that roads have a zone of influence that extends across >70% of the land area. Potentially less than 6% of land escapes any impact, resulting in nearly ubiquitously elevated pollution levels. Generalising from this, we find that, whilst the greatest levels of road pollution are relatively localised around the busiest roads, low levels of road pollution (which may be ecologically significant) are pervasive. Our findings demonstrate the importance of incorporating greater realism into road-effect zones and considering the ubiquity of road pollution in global environmental issues. We used Great Britain as a study area, but the findings likely apply to other densely populated regions at present, and to many additional regions in the future due to the predicted rapid expansion of the global road network.
道路在地球上形成了广阔、普遍且不断扩展的网络，对环境造成了负面影响，这些影响溢出到了“道路影响区”。先前的研究使用任意距离来估计这些区域的区域和全球范围，忽略了不同形式的道路环境影响的空间分布和距离依赖性衰减。以英国作为研究区域，我们使用道路图和污染水平随距离衰减的实际估算值来预测道路污染的空间分布。我们发现，25%的土地距离道路不到 79 米，50%的土地距离道路不到 216 米，75%的土地距离道路不到 527 米。无道路的地区很少，几乎完全局限于高地（平均海拔 391 米），英国只有约 12%的土地距离道路超过 1 公里，不到 4%的土地距离道路超过 2.5 公里。以光、噪音、重金属、NO 和颗粒物 PM 和 PM 为例，我们估计道路的影响范围超过 70%的土地面积。可能只有不到 6%的土地不受任何影响，导致污染水平普遍升高。从这一点推断，我们发现，虽然道路污染的最大程度在最繁忙的道路周围相对集中，但低水平的道路污染（可能具有生态意义）也普遍存在。我们的研究结果表明，在道路影响区中纳入更大的现实性并考虑道路污染在全球环境问题中的普遍性非常重要。我们使用英国作为研究区域，但由于全球道路网络的预测快速扩张，这些发现可能适用于目前人口稠密的其他地区，以及未来的许多其他地区。
