Assessing spatiotemporal variation in dry-wet abrupt alternation using an improved process-based approach

作者：Yaling Yu, Jianyu Fu, Bingjun Liu, Zeqin Huang, Xuejin Tan · 发表于：Journal of Hydrology Regional Studies · 年份：2024 · DOI：10.1016/j.ejrh.2024.101859 · 被引用次数：11 · 研究领域：Image and Signal Denoising Methods

The Pearl River Basin (PRB), located in the south of China, has a tropical to subtropical climate. In this study, we present an improved process-based approach to assess the intensity of the Dry-Wet Abrupt Alternation (DWAA) events, considering both the transition gap (alternation) and the transition rate (urgency) between dry and wet states. Using daily precipitation data from 1961 to 2020 across 75 meteorological stations in the PRB, we analyze the temporal and spatial evolution patterns of DWAA events. The findings reveal that: (1) DWAA events in the western region generally occur less frequently but with higher intensity. (2) Dry-to-wet (D-W) events have an urgency intensity of 1.35, almost twice that of wet-to-dry (W-D) events at 0.69. However, the alternation intensity of W-D is only slightly higher by 0.17 compared to D-W. (3) The alternation and urgency changes in D-W events are asynchronous, with alternation intensity initially decreasing from 9.7 to 9.27, then increasing to 9.58, while urgency decreases continuously from 1.66 to 1.07. (4) The alternation and urgency changes in W-D events are synchronous. The alternation intensity initially decreases from 9.7 to 9.06, then rises to 10.1, while the urgency intensity decreases from 0.68 to 0.58 before subsequently climbing to 0.8. • Improved process-based approach to assess the intensity of drought-flood abrupt alternation. • Changes of alternation and urgency in drought-to-flood events are not synchronized. • Drought-...