Projected mid-century rainfall erosivity under climate change over the southeastern United States
Projected mid-century rainfall erosivity under climate change over the southeastern United States
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气候变化下美国东南部本世纪中叶的降雨侵蚀力预测
DOI：
10.1016/j.scitotenv.2022.161119
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发表时间：
2023
影响因子：
9.8
通讯作者：
Tian, Di
中科院分区：
文献类型：
--
作者：
Takhellambam, Bijoychandra S.;Srivastava, Puneet;Lamba, Jasmeet;McGehee, Ryan P.;Kumar, Hemendra;Tian, Di
最近的观测和气候变化预估表明，决定降雨侵蚀能力的降雨能量、强度、持续时间和频率的变化将放大世界各地的侵蚀速率。然而，这些未来降雨侵蚀力变化的幅度和范围在很大程度上仍然未知，特别是在更精细的分辨率和局部尺度上。由于缺乏可预测的未来亚小时气候数据，以前的研究依赖于总（每小时、每日）降雨数据。在本研究中，美国东南部的侵蚀力是使用没有数据限制的RUSLE2侵蚀力计算方法和最近公布的15分钟降水数据集计算的。该降水数据来源于5个NA-CORDEX气候模式在代表性浓度路径（RCP） 8.5情景下的降水产品。在本数据集中，187个地点的每小时降水气候预估经过了偏差校正，并在时间上缩小到15分钟分辨率。提供了历史时间段（1970-1999年）和未来时间段（2030-2059年）的降水、侵蚀力（r因子）和侵蚀力密度（ED）估算。预估值的集合结果（与历史值相比）显示，降水量、侵蚀力和侵蚀力密度分别增加了14%、47%和29%。未来系综模型显示，年平均r因子为11,237±1299 MJ mm ha−1h−1yr−1。这些发现表明，降雨强度的变化，而不是降水量的变化，可能是导致侵蚀力变化的原因。然而，原始降水数据集和本研究分析中固有的偏差校正和降尺度限制掩盖了这一特定结果。总的来说，沿海和山区预计将经历最大的侵蚀力绝对增加，而其他内陆地区预计将经历最大的相对变化。这项研究从侵蚀力和潜在侵蚀的角度对预估的未来降水特征进行了新的检验。
Recent observations and climate change projections indicate that changes in rainfall energy, intensity, duration, and frequency, which determine the erosive power of rainfall, will amplify erosion rates around the world. However, the magnitude and scope of these future changes in erosive power of rainfall remain largely unknown, particularly at finer-resolutions and local scales. Due to a lack of available projected future sub-hourly climate data, previous studies relied on aggregates (hourly, daily) rainfall data. The erosivity for the southeastern United States in this study was calculated using the RUSLE2 erosivity calculation method without data limitation and a recently published 15-min precipitation dataset. This precipitation data was derived from five NA-CORDEX climate models' precipitation products under the Representative Concentration Pathway (RCP) 8.5 scenario. In this dataset, hourly climate projections of precipitation were bias-corrected and temporally downscaled to 15-min resolution for 187 locations with collocated 15-min precipitation observations. Precipitation, erosivity (R-factor), and erosivity density (ED) estimations were provided for historical (1970–1999) and future (2030–2059) time periods. Ensemble results for projected values (as compared to historical values) showed increase in precipitation, erosivity, and erosivity density by 14 %, 47 %, and 29 %, respectively. The future ensemble model showed an average annual R-factor of 11,237±1299 MJ mm ha−1h−1yr−1. These findings suggest that changes in rainfall intensity, rather than precipitation amount, may be driving the change in erosivity. However, the bias correction and downscaling limitations inherent in the original precipitation dataset and this study's analyses obscured this particular result. In general, coastal and mountainous regions are expected to experience the greatest absolute increase in erosivity, while other inland areas are expected to experience the greatest relative change. This study offers a novel examination of projected future precipitation characteristics in terms of erosivity and potential future erosion.