Future urban land expansion and implications for global croplands
Future urban land expansion and implications for global croplands
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DOI：
10.1073/pnas.1606036114
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发表时间：
2017-08-22
影响因子：
11.1
通讯作者：
Seto, Karen C.
中科院分区：
文献类型：
--
作者：
d'Amour, Christopher Bren;Reitsma, Femke;Seto, Karen C.
城市扩张通常发生在农田上。然而，对于未来全球城市扩张模式将如何影响世界耕地，几乎没有科学上的理解。在这里，我们将城市扩展的空间显式预测与全球农田和作物产量的数据集结合起来。我们的结果表明，到2030年，城市扩张将导致全球耕地面积减少1.8%-2.4%，地区差异很大。全球因城市扩张而损失的耕地中，约80%将发生在亚洲和非洲。在亚洲和非洲，将失去的大部分农田的生产力是全国平均水平的两倍多。亚洲将经历最高的耕地绝对损失，而非洲国家将经历最高百分比的农田损失。在全球范围内，2000年，可能失去的农田占全球农作物产量的3%-4%。预计城市扩张将发生在生产率是全球平均水平1.77倍的农田上。耕地的丧失很可能伴随着其他可持续风险并威胁生计，不同的特大城市地区具有不同的特点。因此，城市地区扩展的治理成为确保全球南方农业经济中生计的一个关键领域。
Urban expansion often occurs on croplands. However, there is little scientific understanding of how global patterns of future urban expansion will affect the world's cultivated areas. Here, we combine spatially explicit projections of urban expansion with datasets on global croplands and crop yields. Our results show that urban expansion will result in a 1.8-2.4% loss of global croplands by 2030, with substantial regional disparities. About 80% of global cropland loss from urban expansion will take place in Asia and Africa. In both Asia and Africa, much of the cropland that will be lost is more than twice as productive as national averages. Asia will experience the highest absolute loss in cropland, whereas African countries will experience the highest percentage loss of cropland. Globally, the croplands that are likely to be lost were responsible for 3-4% of worldwide crop production in 2000. Urban expansion is expected to take place on cropland that is 1.77 times more productive than the global average. The loss of cropland is likely to be accompanied by other sustainability risks and threatens livelihoods, with diverging characteristics for different megaurban regions. Governance of urban area expansion thus emerges as a key area for securing livelihoods in the agrarian economies of the Global South.