气象
氣象
기상
METEOROLOGICAL MONTHLY
2013年
12期
1635-1641
,共7页
极端降水%频率%强度%城市化%北京
極耑降水%頻率%彊度%城市化%北京
겁단강수%빈솔%강도%성시화%북경
extreme precipitation%frequency%intensity%urbanization%Beijing
提应用北京地区20站1971-2010年降水记录及城市发展数据,采用百分位方法定义极端降水事件的阈值,分析了北京地区夏季极端降水事件的时空变化特征及城市化的影响。结果表明:(1)北京夏季极端降水阈值及频数存在较强局地性特征,基本沿地形高度分布,极端降水频数多发区与高阈值区不完全对应;(2)近40年极端降水频率及强度均呈现下降趋势,年际及年代际差异显著;(3)城市化发展不同阶段极端降水强度及频数均有不同的分布形态,城市化对城市不同区域极端降水影响不一样,城市化导致城市下风向近郊区极端降水强度、次数均表现为增多趋势;(4)城市对极端降水的影响还与天气过程强度有关,强天气背景下城市对极端降水频数的影响程度高于对降水强度的影响。
提應用北京地區20站1971-2010年降水記錄及城市髮展數據,採用百分位方法定義極耑降水事件的閾值,分析瞭北京地區夏季極耑降水事件的時空變化特徵及城市化的影響。結果錶明:(1)北京夏季極耑降水閾值及頻數存在較彊跼地性特徵,基本沿地形高度分佈,極耑降水頻數多髮區與高閾值區不完全對應;(2)近40年極耑降水頻率及彊度均呈現下降趨勢,年際及年代際差異顯著;(3)城市化髮展不同階段極耑降水彊度及頻數均有不同的分佈形態,城市化對城市不同區域極耑降水影響不一樣,城市化導緻城市下風嚮近郊區極耑降水彊度、次數均錶現為增多趨勢;(4)城市對極耑降水的影響還與天氣過程彊度有關,彊天氣揹景下城市對極耑降水頻數的影響程度高于對降水彊度的影響。
제응용북경지구20참1971-2010년강수기록급성시발전수거,채용백분위방법정의겁단강수사건적역치,분석료북경지구하계겁단강수사건적시공변화특정급성시화적영향。결과표명:(1)북경하계겁단강수역치급빈수존재교강국지성특정,기본연지형고도분포,겁단강수빈수다발구여고역치구불완전대응;(2)근40년겁단강수빈솔급강도균정현하강추세,년제급년대제차이현저;(3)성시화발전불동계단겁단강수강도급빈수균유불동적분포형태,성시화대성시불동구역겁단강수영향불일양,성시화도치성시하풍향근교구겁단강수강도、차수균표현위증다추세;(4)성시대겁단강수적영향환여천기과정강도유관,강천기배경하성시대겁단강수빈수적영향정도고우대강수강도적영향。
Based on the summer precipitation data of 20 stations in Beijing and its urban development statis-tical data during 1971-2010,and defining the 95th percentile as the threshold of extreme precipitation for each station,the characteristics of the spatio-temporal distribution and the linear trend of extreme precipi-tation events with different durations and city effect of local precipitation are analyzed.The results indicate that the extreme precipitation event frequency shows a gradual decreasing trend from west to east,which is remarkably different from the precipitation distribution.There exist distinctive spatial differences in the distributive features and changes of the threshold values,frequencies,and rainfall of extreme precipitation events.The averaged intensity and frequency of extreme precipitation in Beijing Area show a descending trend in the past 40 years and have significant difference at interannual and interdecadal changes.The im-pact of urbanization on the intensity and frequency of extreme precipitation has become more and more ap-parent.Urbanization can not only enhance rain island effect but also make an influence on precipitation in downwind areas;moreover,urbanization can also increase the intensity and frequency of local extreme pre-cipitation.