摘要
为总结全国降水特征,并探究降水历时的分布,对中国698个气象站56年连续日降水数据,从降水的季节分布、极端特征、持续时间3个方面分析降水特征的空间分布和年际变化,并利用伽马分布对降水历时曲线进行拟合和参数估计,分析影响拟合参数的潜在物理因素。结果显示:(1)降水趋势总体呈现东南地区增加,中部下降,东部、西北、东北冬季降水量增加且分布范围较广,从中国东南地区到西北地区,降水百分位的变化趋势呈先升再减再升,99百分位降水阈值的分布更不均匀,临河站的降水百分位变化趋势下降最大,尤其是湿日降水百分位,湿期在西南和中部地区处于下降趋势,沿海和西北地区处于上升趋势,且流域旱涝持续时间分布特征在大部分地区表现出相反状态,湿期的年际变化相较于干期小;(2)伽马分布对降水量有较好的拟合效果,尺度参数β与降水量和降水百分位的相关性较高,且对强降水事件的极端降水阈值有更好的表现,这一发现能够为后续基于物理影响因素的降水过程研究提供理论支持。
In order to summarize the precipitation characteristics in China and explore the distribution of precipitation duration,this paper selects 56 years of continuous daily precipitation data from 698 meteorological stations in China and analyzes the spatial distribution and inter-annual variations of precipitation characteristics in terms of seasonal distribution,extreme characteristics,and precipitation duration.The paper also uses the Gamma distribution to fit the precipitation duration curves and estimate the parameters and analyzes the potential factors that affect the fitting parameters.The results show that①the precipitation generally shows an increase in the southeast part and a decrease in the central part of China,with an increase and a wider distribution of winter precipitation in the east,northwest,and northeast parts.From the southeast to the northwest of China,the trend of precipitation percentile change shows an increase,then a decrease,and then an increase again,and the distribution of the 99-percentile precipitation thresholds is more uneven.The trend of the precipitation percentile at the Linhe station shows the greatest decrease,especially the wet-day precipitation percentile.The wet period is in a decreasing trend in the southwest and central parts and in an increasing trend in the coastal and northwestern parts.The distribution characteristics of drought and flooding durations in the basin show the opposite state in most regions,and the inter-annual variation of the wet period is smaller than that of the dry period.②The Gamma distribution has a better fitting effect on precipitation.The scale parameterβhas a higher correlation with precipitation amount and precipitation percentile and better performance on extreme precipitation thresholds for heavy precipitation events.These findings can provide theoretical support for the subsequent research on precipitation processes based on physical influencing factors.
作者
周雨
张育嘉
苗昌盛
ZHOU Yu;ZHANG Yujia;MIAO Changsheng(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China;Shanghai Huajin Construction Co.,Ltd,Shanghai 200063,China)
出处
《人民珠江》
2024年第3期48-58,共11页
Pearl River
基金
上海临港滨海海洋生态保护修复项目(二标)(2201PD0001)。
关键词
伽马分布
降水历时曲线(PDC)
降水的空间分布及年际变化
估计参数
物理控制
Gamma distribution
precipitation duration curve
spatial distribution and inter-annual variation of precipitation
estimation parameters
physical control
