洪水是最广泛和灾难性的自然灾害之一。耕地受洪水影响直接关系到耕地质量和粮食安全,所以绘制这种暴露的时空演变图尤为重要,特别关注更长的时间序列和更高分辨率的尺度。这项研究是首次使用2000-2019年全球土地分析与发现(GLAD)数据集的30m分辨率分析全球农田暴露于洪水(CEF)的时空变化。研究结果表明:(1)全球CEF面积总共增加了83,429.50平方公里,即7.75%,从2000年到2019年;(2)只有北美的CEF呈下降趋势,CEF增幅最大的地区是南亚;(3)CEF在23个流域,包括恒河,印度河,密西西比州,长江,多瑙河,2019P占全球总量的79.88%;(4)2019P,中国拥有全球最大的CEF,达到239,525.07km2。发展最快的CEF是印度,贡献了全球CEF增长的16.36%。美国的CEF出现了下降趋势;(5)在评估世界各国的CEF时使用了两个构建的指标,共有46个国家被认为处于最高风险水平,主要在欧洲和亚洲。基于这些结论,我们进行了冷/热点分析,以揭示这种现象的空间异质性和可能的驱动因素,并提出管理建议,以限制洪泛区耕地的风险。
Flooding is one of the most widespread and catastrophic natural disasters. The exposure of cropland to floods is directly related to the quality of cropland and food security, so it is particularly important to map the spatiotemporal evolution of this exposure, with a specific focus on longer time series and higher resolution scales. This study is the first of its kind to analyse the worldwide spatiotemporal variability of Cropland Exposure to Flooding (CEF) with the 30 m resolution of Global Land Analysis & Discovery (GLAD) dataset during 2000-2019. The findings indicate that: (1) the global CEF area increased by a total of 83,429.50 km2 or 7.75 %, from 2000 to 2019; (2) only North America\'s CEF showed a downward trend, and the region with the largest increase in CEF was South Asia; (3) the CEF in 23 river basins, including Ganges, Indus, Mississippi, Yangtze, and Danube, accounted for 79.88 % of the global total in 2019P; (4) in 2019P,
China had the largest CEF globally, reaching 239,525.07 km2. The fastest growing CEF was India, contributing 16.36 % of the global CEF growth. The CEF of United States experienced a reduction trend; (5) two constructed indicators were used in evaluating the CEF of countries worldwide, and a total of 46 countries are considered to be at the highest level of risk, mainly in Europe and Asia. Based on these conclusions, we carried out a cold/hot spot analysis to reveal the spatial heterogeneity and possible driving factors in this phenomenon, and we offer management suggestions to limit the risks to cropland in the floodplains.