基于台站和APHRO资料的四川降水季节性特征

Seasonal Precipitation Characteristics in Sichuan Based on Station Observations and APHRODITE Data

  • 摘要: 基于1991—2020年四川省153个国家级台站资料,结合APHRODITE计划的高分辨率逐日网格化降水资料,采用降水集中度(Precipitation Concentration Degree,PCD)和降水集中期(Precipitation Concentration Period,PCP)指数,研究了四川省降水的时空变化特征、季节性特征和年际变率。结果表明:(1)从空间分布看,四川省降水频次高、强度大的区域主要集中在大渡河支流青衣江中下游、盆地西部边缘、渠江流域的巴河、州河上游和嘉陵江支流东河上游等地;PCD和PCP指数均呈“V”型分布特征且极大(小)值区域对应较好。(2)从时间变化看,PCD指数极大值在年际尺度上呈增长趋势且增长的突变点在1998年附近,而PCD指数极小值年际波动较小,说明四川降水的极端性在增强;PCP指数极大值和极小值在年际尺度上均呈递减趋势,说明四川雨季的来临会提前。

     

    Abstract: Based on the data from 153 national meteorological stations in Sichuan Province from 1991 to 2020, combined with high-resolution gridded precipitation data from the APHRODITE project, the spatiotemporal variations, seasonal characteristics, and interannual variability of precipitation are studied by using the Precipitation Concentration Degree (PCD) and Precipitation Concentration Period (PCP) indices. The results demonstrate that: (1) From the perspective of spatial distribution, the areas with high frequency and intensity of precipitation in Sichuan Province are mainly concentrated in the middle and lower reaches of the Qingyi River, the western edge of the Basin, the Bahe River, the upper reaches of the Zhouhe River and the upper reaches of the Donghe River. The PCD and PCP indexes show a "V" type distribution characteristics and the maximum (small) value regions correspond well. (2) From the perspective of time variation, the maximum value of PCD index shows an increasing trend at the interannual scale, with the mutation point of growth occurring around 1998, while the minimum value of PCD index shows little interannual fluctuation, indicating the increasing of the extreme precipitation in Sichuan. The maximum and minimum values of PCP index show a decreasing trend on the interannual scale, indicating an earlier onset of the rainy season in Sichuan.

     

/

返回文章
返回