近30年三峡库区洪涝特征及建库前后致涝气候因子的差异  

THE FLOOD FEATURES OF THE THREE GORGES RESERVOIR REGION FOR THE PAST 30 YEARS AND THE DIFFERENCE OF FLOOD-CAUSING CLIMATIC FACTORS BEFORE AND AFTER THE CONSTRUCTION OF THE RESERVOIR

作　　者：李强 李永华[2,3] 王中 廖峻 周锁铨[3] 

机构地区：[1]重庆市气象台,重庆401147 [2]重庆市气象科学研究所,重庆401147 [3]南京信息工程大学气象灾害省部共建教育部重点实验室,江苏南京210044

出　　处：《热带气象学报》2010年第6期750-758,共9页Journal of Tropical Meteorology

基　　金：重庆市自然科学基金计划重点项目(CSTC;2008BA0022);中国气象局成都高原气象研究所开放基金项目(LPM200814);重庆市气象局2010年科技计划项目(zl-201003)共同资助

摘　　要：利用三峡库区1980—2007年逐日雨量观测资料和NCEP/NCAR逐月再分析资料,分析了近30年来三峡库区洪涝变化特征,并对三峡库区洪涝典型年份大气环流形势进行合成分析,进一步研究了典型洪涝年份不同关键区水汽输送特征。近30年来,三峡库区洪涝有明显的年际、年代际差异;近年来,三峡库区年均洪涝和区域性洪涝强度均呈减弱趋势,而区域性洪涝较为频繁;大气环流合成分析表明,乌拉尔山高压脊显著加强,导致经向性环流增强,引导冷空气南下,与低纬北上暖湿气流交汇,有利于三峡库区降水,易于产生洪涝灾害;三峡库区蓄水前后在蒙古和我国东北地区的环流背景合成明显不同,蓄水前典型洪涝年份环流异常更有利于降水;在强盛的偏南气流影响下,蓄水前典型洪涝年份水汽输送指示特征较蓄水后的洪涝年份水汽输送更加明显,更有利于三峡库区降水;典型洪涝年2004、2007年,关键区水汽输送有明显的候变化特征,但在典型洪涝事件中各个关键区水汽输送指示特征并不明显。Based on the observed daily precipitation data in the Three Gorges Reservoir region and the NCEP/ NCAR reanalysis data from 1980 to 2007,the flood temporal evolution were investigated and large-scale circulation synthetic characteristics of the representative flood years were studied in recent 30 years.Following,the moisture transportation features were discussed in different water vapor key areas.The inter-annual and inter-decadal distinctions were remarkable for recent 30 years in the Three Gorges Reservoir area.In recent year,the annual mean flood intensity and regional flood intensity tended to weaken,and regional flood happened frequently.The results of synthetic analysis on the large-scale circulation showed that it tended to rain when cold air from the north and warm and wet air from the south converged in the Three Gorges Reservoir area with the ridge strengthening,owing to the enhancement of meridional circulation in the Ural Mountains,which led to flood in this area.The large-scale circulation patterns were different obviously in Mongolia plateau and Northeast China before and after the Three Gorges Reservoir water storing.The circulation anomalies were prone to give rise to rainfall prior to the Three Gorges Reservoir water store.Under the influence of strong southerly flows,the indicative characteristics of moisture transportation were more obvious before the water storage than that after the water storage,which was more helpful to rainfall.There were noticeable pentad-based variations in the key areas of moisture transportation between typical flood years of 2004 and 2007.The indicative of water vapor transport was not remarkable in key areas in typical flood events.

关 键 词：三峡库区 洪涝指数 关键区 水汽输送 

分 类 号：P467[天文地球—大气科学及气象学]