雷达遥感显示,全球范围内的降雨侵蚀性可能被低估
Qiang Dai1, Jingxuan Zhu1,2, Guonian Lv1
1Key Laboratory of VGE of Ministry of Education, Nanjing Normal University, Nanjing, China.
Science advances
|August 9, 2023
概括
这项研究引入了一种使用雷达数据测量降雨动能 (RKE) 的新方法,比传统的基于强度的估计提高了准确性. 这一进展对于了解土壤侵蚀和指导全球保护工作至关重要.
科学领域:
- 地球和环境科学 地球和环境科学
- 水文学的水文学
- 土壤科学 土壤科学
背景情况:
- 降雨动能 (RKE) 是土壤侵蚀的主要驱动因素.
- 目前的RKE测量依赖于经验性降雨强度 (KE-I) 关系,这些关系对于数据稀缺地区的区域化很差.
- 准确的RKE数据对于有效的土壤保护和可持续的土地管理至关重要.
研究的目的:
- 介绍使用雷达反射率的首个基于微物理的全球降雨RKE流量检索方法.
- 将这种新方法的性能与传统的实证KEI关系进行比较.
- 要突出在数据稀缺的地区对RKE和降雨侵蚀性的潜在低估.
主要方法:
- 开发了一种新的方法来估计来自不同频率的雷达反射功率的RKE流量.
- 验证了新的RKE流量估计与地面流量计数据.
- 与广泛使用的经验KEI关系相比,评估了新方法的性能.
主要成果:
- 基于微物理学的RKE流量方法在与实证KEI关系相比,表现优越.
- 发现RKE和由此产生的降雨侵蚀性的普遍低估,特别是在低收入国家 (~20%).
- 这些低估值可能会严重误导土壤侵蚀保护实践.
结论:
- 新型基于雷达的RKE流量方法为RKE估计提供了更准确和全球适用的替代方案.
- 在脆弱地区低估RKE对可持续的陆地生态系统发展构成重大风险.
- 改善RKE评估对于有针对性和有效的土壤侵蚀减缓战略至关重要.
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