CAJ | 학술논문

利用广义极值分布和百分位两种阈值确定方法,对我国465个气象站点不同极端程度的小时降水强度阈值进行了分析.广义极值分布结果表明,重现期为2、5、10、50 a的降水强度阈值具有一致的空间分布特征:华南沿海阈值最高,长江中下游地区北部、四川盆地西部、华北地区东部次之,云南中西部、华北西部和东北西部阈值相对更低,最小值出现在我国西部地区.百分位法得到的阈值空间分布呈现出与广义极值分布结果较为一致的东南大、西北小的整体特征.考察465站中位数发现,第99.9百分位的强度阈值与二年一遇降水的阈值接近.具体分析各站第99.9百分位降水阈值对应的重现期发现,长江流域及其以南地区重现期大多低于2 a;35°N一带重现期长于4 a;我国北方和西北部分地区重现期长于8 a.
이용엄의겁치분포화백분위량충역치학정방법,대아국465개기상참점불동겁단정도적소시강수강도역치진행료분석.엄의겁치분포결과표명,중현기위2、5、10、50 a적강수강도역치구유일치적공간분포특정:화남연해역치최고,장강중하유지구북부、사천분지서부、화북지구동부차지,운남중서부、화북서부화동북서부역치상대경저,최소치출현재아국서부지구.백분위법득도적역치공간분포정현출여엄의겁치분포결과교위일치적동남대、서북소적정체특정.고찰465참중위수발현,제99.9백분위적강도역치여이년일우강수적역치접근.구체분석각참제99.9백분위강수역치대응적중현기발현,장강류역급기이남지구중현기대다저우2 a;35°N일대중현기장우4 a;아국북방화서북부분지구중현기장우8 a.
@@@@Using two methods in thresholds definition, Generalized Extreme Value (GEV) distribution and percentile measurement, the thresholds of hourly rainfall intensity at 465 stations in mainland China are analyzed on different extreme scales. GEV distribution shows that the thresholds for 2, 5, 10, and 50-year return period share an identical spatial distribution, which exhibits highest values in coastal region of southern China;higher values in the north of the middle and lower reaches of the Yangtze River valley, west of Sichuan basin, and east of northern China;lower values in the midwest of Yunnan, west of northern China, and west of northeast China;lowest values in the western Chi-na. Meanwhile, the percentile results have the same distribution pattern as GEV outcomes on a whole, which present higher thresholds in southeast and lower thresholds in northwest. The medians at 465 stations are analyzed. The results indicate that intensity thresholds of the 99.9th percentile are close to intensity thresholds of 2-year return period. Having converted the thresholds of the 99.9th percentile to return period level, it is shown that the return periods are under 2-year in Yangtze River valley and its southern area;longer than 4-year along 35°N;longer than 8-year in parts of northern China and northwest China.