研究提出了第一个在不同频率下,基于全球降雨微物理学的降雨动能 (RKEMPH)通量反演雷达反射率。研究结果表明,RKEMPH 通量优于从广泛使用的经验 KE-I 关系(RKEKE-I)得到的降雨动能估计,该关系式使用地面探测仪验证。研究发现 RKEKE-I 的潜在广泛被低估,这在一些低收入国家尤为突出,对降雨动能和由此产生的降雨侵蚀力的低估约为 20%。鉴于有证据表明这些国家遭受更大的降雨引起的土壤侵蚀,这些低估将误导陆地生态系统可持续发展的保护做法。
据了解,降雨动能(RKE)是驱动表层土壤降雨侵蚀力的最关键的因素之一,对降雨动能的直接测量是有限的,而是依赖于动能和降雨强度之间的经验关系(KE-I 关系),对于数据缺乏的地区,这些关系也没有很好地被区域化。
附:英文原文
Title: Radar remote sensing reveals potential underestimation of rainfall erosivity at the global scale
Author: Qiang Dai, Jingxuan Zhu, Guonian Lv, Latif Kalin, Yuanzhi Yao, Jun Zhang, Dawei Han
Issue&Volume: 2023-08-09
Abstract: Rainfall kinetic energy (RKE) constitutes one of the most critical factors that drive rainfall erosivity on surface soil. Direct measurements of RKE are limited, relying instead on the empirical relations between kinetic energy and rainfall intensity (KE-I relation), which have not been well regionalized for data-scarce regions. Here, we present the first global rainfall microphysics–based RKE (RKEMPH) flux retrieved from radar reflectivity at different frequencies. The results suggest that RKEMPH flux outperforms the RKE estimates derived from a widely used empirical KE-I relation (RKEKE-I) validated using ground disdrometers. We found a potentially widespread underestimation of RKEKE-I, which is especially prominent in some low-income countries with ~20% underestimation of RKE and the resultant rainfall erosivity. Given the evidence that these countries are subject to greater rainfall-induced soil erosion, these underestimations would mislead conservation practices for sustainable development of terrestrial ecosystems..
DOI: adg5551
Source: https://www.science.org/doi/full/10.1126/sciadv.adg5551