Gardi Ciro, Florczyk Aneta Jadwiga, Scalenghe Riccardo
European Food Safety Authority, Alpha Unit, Parma, Italy.
Joint Research Center, European Commission, Ispra, Italy.
Heliyon. 2021 Jan 9;7(1):e05860. doi: 10.1016/j.heliyon.2020.e05860. eCollection 2021 Jan.
The use of soil as support for built-up areas represents only one of its several functions. Farmlands at the fringe of conurbations have more chance of being converted into built-up areas due to the favourable topography and the accessibility to existing infrastructure, being in the vicinity of urban areas. We analysed the global land-take during the period 2000-2014. The data are based on a global dataset describing the spatial evolution of human settlements using the Global Human Settlement Layer, which was derived from Landsat images collected in 1975, 1990, 2000 and 2014. Although the global land-take represents roughly 0.1% of the global terrestrial Earth, it affects 1% of the naturally fertile soils, according to the proposed Soil Productivity Indexes (SPI), based upon the potential soil productivity, calculated on the basis of the Harmonized World Soil Database. We have found that, few large conurbations develop on potentially high productive soil, while scarcely productive soils sustain the expansion of several megalopolises. On a global scale and through the centuries, considered comparatively as individual overall age of settlements, a trend between the intrinsic quality of the soils and its use for settlement purposes as major competitor, was not observed.
将土壤用作建成区的支撑仅仅是其多种功能之一。由于地形有利且靠近城市地区，现有基础设施可达，位于城市边缘的农田更有可能转变为建成区。我们分析了2000年至2014年期间的全球土地占用情况。数据基于一个全球数据集，该数据集使用全球人类住区层描述人类住区的空间演变，全球人类住区层源自1975年、1990年、2000年和2014年收集的陆地卫星图像。根据基于统一世界土壤数据库计算的潜在土壤生产力提出的土壤生产力指数（SPI），尽管全球土地占用约占全球陆地面积的0.1%，但它影响了1%的天然肥沃土壤。我们发现，很少有大型城市在潜在高产土壤上发展，而低产土壤却支撑着几个大都市的扩张。在全球范围内，经过几个世纪，相对作为定居点的整体个体年龄来考虑，未观察到土壤内在质量与其作为主要竞争者用于定居目的之间的趋势。
