Climatic characteristics and long-term variation of regional rainstorm process in the Three Gorges area in recent 62 years
[Objective]To fully understand the beginning and end time of regional rainstorm process climatic characteristics and long-term change rules of regional rainstorm process in the Three Gorges region,so as to provide scientific basis for flood control and disaster reduction and water resources management in the Three Gorges Reservoir area.[Methods]Based on daily precipita-tion data of 33 national meteorological stations in the Three Gorges region from 1961 to 2022 and the regional rainstorm monitoring indexes currently adopted in Chongqing,the regional rainstorm process in the Three Gorges region was objectively identified,and the climatic characteristics and long-term change rules of the regional rainstorm process were analyzed by various mathematical statistic method.[Results]The results show that:(1)Nearly two-thirds of the heavy rain in the Three Gorges area occurs in re-gional form,with an average annual regional heavy rain process of 8.4 times,mainly from May to September,especially from June to July as the concentrated period.The average date of the first regional rainstorm is May 8,and the average end date of the last rainstorm is September 17.The average rainstorm coverage area of each process is 8.6 stations,the duration is 1.3 d,and the average rainstorm intensity is 74.7 mm/d.(2)The annual frequency of regional heavy rainfall processes in the Three Gorges region has a variation cycle of about 2～3 a and 8 a,and the average coverage area of regional heavy rainfall processes has a vari-ation cycle of 4～6 a and 8～11 a.(3)In recent 62 a,the first occurrence date of the annual regional heavy rainfall process in the Three Gorges area was significantly advanced,the last end date had no significant change,and the occurrence period was significantly longer;The occurrence frequency,average duration,average coverage and average comprehensive intensity showed no obvious change trend,but the average rainstorm intensity showed an increasing trend.(4)In the past 62 a years,there has been no abrupt change in the regional rainstorm process indexes in the Three Gorges area.[Conclusion]The results provide scientific support for flood control and disaster reduction,water resources management in the Three Gorges region,and respon-ding to social concerns about the impact of the Three Gorges Project on local climate.
regional rainstorm processclimatic characteristicsthe trend of changeperiod of changeThree Gorges regionextreme rainfallprecipitationThree Gorges Reservoir
万方数据
维普
