鄱阳湖区分级雨日及雨量变化特征分析  

Variation Characteristics of Graded Rainy Days and Rainfall Amount in Poyang Lake Area

作　　者：张范平[1,2,3] 许新发[1,2,3] 成静清[1,2,3] 温天福[1,2,3] 刘章君 ZHANG Fan-ping;XU Xin-fa;CHENG Jing-qing;WEN Tian-fu;LIU Zhang-jun(Department of Water Resources and Environment, Jiangxi Provincial Institute of Water Sciences,Nanchang330029,China;Research Center of Water Resources and Ecological Environment of Poyang Lake under Ministry of Water Resources, Jiangxi Provincial Institute of Water Sciences, Nanchang 330029,China;Jiangxi Provincial Key Laboratory of Water Resources and Environment of Poyang Lake,Jiangxi Provincial Institute of Water Sciences, Nanchang 330029,China)

机构地区：[1]江西省水利科学研究院水资源水环境研究所,南昌330029 [2]江西省水利科学研究院,水利部鄱阳湖水资源水生态环境研究中心,南昌330029 [3]江西省水利科学研究院,江西省鄱阳湖水资源与环境重点实验室,南昌330029

出　　处：《长江科学院院报》2020年第7期22-28,34,共8页Journal of Changjiang River Scientific Research Institute

基　　金：江西省水利科技重大项目(KT201601,201821ZDKT07,201821ZDKT15)。

摘　　要：为了分析鄱阳湖区降雨量的变化特征,按照相关标准对年降雨日数和降雨量进行分级,深入研究各级雨日(量)的年际变化特征和年内分配规律。利用鄱阳湖区都昌站1953—2012年逐日降雨资料,采用趋势突变检验、Hurst指数、集中度和集中期等方法对鄱阳湖区年和季节分级雨日(量)的变化特征进行分析。研究结果表明:①鄱阳湖区年平均降雨日数为134 d,其中,小雨日数、中雨日数、大雨日数和暴雨日数所占雨日的比例分别为70.9%,18.66%,8.2%,2.98%;过去几十年,年总雨日数、小雨日数和暴雨日数均呈现显著减少的趋势并可能持续减少,年总雨日数在1978年发生突变,突变后雨日数减少了14 d;季节性降雨中,春、夏2季以大雨暴雨为主,秋、冬2季以小雨、中雨为主。②鄱阳湖区年平均降雨量为1335.66 mm,小雨、中雨、大雨和暴雨占年降雨的比例分别为20.74%,29.50%,27.35%,22.41%;过去几十年,年降雨量呈显著减少趋势并可能继续减少,并在1976年发生突变,突变后年平均降雨量减少了301.26 mm。③鄱阳湖区降雨集中度平均为0.4,但受降雨年内分配的影响,降雨集中度年际差异较大;降雨集中期主要集中在3月中旬—6月中旬,其中,4月中旬—5月中旬占了71.43%。鄱阳湖区降雨日数的减少主要是由小雨日数减少引起的,降雨量的减少是各级雨量共同减少造成的;降雨集中度的大小与大雨和暴雨量所占年降雨量的比例密切相关,且与降雨不均匀系数显著正相关。研究结果可为进一步认识鄱阳湖湿地水文情势变化特征提供依据。In pursuance of investigating the variation characteristics of rainfall amount in Poyang Lake area,the daily rainfall dataset(including rainy days and rainfall amount)of Duchang hydrometric station,located at middle Poyang Lake,with a 60-year common record length of the daily rainfall from 1953 to 2012,is classified into different levels according to rainfall classification standard.The variation characteristics and distribution features of rainy days and rainfall amount are examined with methods of trend and catastrophe test,Hurst index,precipitation concentration degree(PCD)and precipitation concentration period(PCP).Results reveal that:(1)The number of average annual rainy days is 134,of which light rainy days,moderate rainy days,heavy rainy days and torrential rainy days account for 70.9%,18.66%,8.2%and 2.98%,respectively;during the past decades,the total annual rainy days,light rainy days and torrential rainy days exhibit a significant decreasing trend and is likely to continue.Total annual rainy days changed abruptly(reduced by 14 days)in 1978.In spring and summer,heavy and torrential rainy days occupy a high portion,whereas in autumn and winter,light and moderate rainy days are dominant.(2)The average annual rainfall amount is 1335.66 mm,of which light rain,moderate rain,heavy rain and torrential rain account for 20.74%,29.50%,27.35%and 22.41%,respectively;the annual rainfall amount exhibits a significant and lasting decreasing trend and changed abruptly(declined by 301.26 mm)in 1976.(3)The precipitation concentration degree(PCD),which varies greatly due to distinguishable distribution feature of rainy days and precipitation in different years,has an average of 0.4;the precipitation concentration period(PCP)is mainly from mid-March to mid-June,of which from mid-April to mid-May accounts for 71.43%.The decrease of rainy days is mainly caused by declining light rainy days,but annual rainfall amount is affected by rainfall of all levels.PCD,closely related to the ratio of heavy rain and torrential rain to ann

关 键 词：分级雨日 分级雨量 降雨集中度 变化特征 鄱阳湖区 

分 类 号：P426.6[天文地球—大气科学及气象学]