摘要
为揭示广元极端降水的变化趋势,利用1961~2015年逐时和逐日降水数据分析广元降水特征和极端降水事件变化。结果表明,广元降水总量年际变化不明显,小时降水越来越极端;在02~06时,小时降水量呈增加趋势,苍溪和青川降水年际倾向率日变化为单峰单谷型,旺苍、广元和剑阁为双峰单谷型。广元市大部分地区短时强降水次数逐年增加,在1980s和2000年后有明显增加,特别是1980s的旺苍站,增幅达到71%;广元小时及日降水最大值有增加趋势。1961~2015年,日降水量≥25mm天数(R25mm)、日降水强度(SDⅡ)和极端降水量(R95)的年际倾向率分别为0.0558d·a^(-1)、0.0168mm·d^(-1)·a^(-1)和0.5998mm·a^(-1),而持续降水日数(CWD)则以-0.0202d·a^(-1)的速率减少,广元每年降水的持续天数在减少,但降水情况越来越极端。
To reveal the trend of extreme precipitation in Guangyuan of Sichuang, base on the houon data during 1961 -2015 to analysis the characteristics changing tendency of the diurnal variation of precipitation, hourly precipitation intensity, short _ period heavy precipitation, and select the four extreme precipitation indices recommended by the World Meteorological Organization to study the extreme precipitation events in Guangyuan. The results indicate that： The intern-nnual variability of total precipitation in Guangyuan is not obvious, but hourly precipitation The hourly precijDitation shows an increasing trend from 02： 00am to 0 6： 00am, and diurnal variation of trend magnitudes of pre-cipitation in Cangci and Qingchuan is single peak - valley pattern, and Wangcang, Guangyuan and Jiange is one valley between two peaks pattern, the frequency of short _ period heavy precipitation in most area of Guangyuan teniecadal change in the 1980s has an obvious increase esjDecially in Wangcang which increases 71% , the maximum houdaily precipitation in Guangyuan are increasing. The trend magnitudes of very heavy precipitation days （R25 mm）, simple dailyintensity index （ SDII） and very wet day precipitation （ R95 ） is 0. 0558d · a -1 , 0. 0168mm · d- 1 a- 1 and 0. 5998mm · a- 1 , respectively, while consecutive wet days （ CWD） decreased by 0. 0202d
·a- 1 during 1961 -2015 in Guangyuan, which the number of continuous precipitation days is decreasing per year, while the precipitation is getting more and more extreme.
出处
《高原山地气象研究》
2017年第3期52-57,共6页
Plateau and Mountain Meteorology Research
基金
四川科技支撑计划2015SZ0214
关键词
小时降水
极端降水
短时强降水
变化趋势
hourly precipitation, precipitation extremes, short-period heavy precipitatio trend of change
