To analyze the daily-scale spatiotemporal process of the persistent extreme drought in Sichuan and Chongqing in 2022, the daily-scale drought index was calculated based on the ERA5-Land meteorological data from 2018 to 2022. Three-threshold tour theory was used to identify persistent extreme drought events in the Sichuan-Chongqing Region in 2022. The duration, intensity, and frequency of the drought across different terrain types were extracted, and the spatial heterogeneity of drought processes was revealed. The results show that the majority of pixels in the Sichuan-Chongqing region were subjected to two drought events in 2022 and the worst of the drought occurred on 22 August. The average duration of persistent extreme drought in Sichuan-Chongqing region during the summer was 67 days, with the longest duration being 159 days and the shortest being 17 days, showing a increasing trend from west to east. The earliest drought started on 16 June and the latest on 28 August. The correlation between drought severity and drought duration reached 0.98, and their trends were consistent. In different terrain areas, the first type of drought process occurred in spring, with an average of 3.5 drought events, an average total duration of 166 days and an average severity of 193.63. The second type of drought with no drought in spring occurred on average 2.2 times, with an average duration of 120.6 days and an average severity of 136.27, which is only 70.38% of the first type. The research results can provide theoretical basis and technical support for regional daily drought monitoring.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |