湖北省双季稻生长季降水及洪涝变化特征

CHARACTERISTICS AND IMPACT OF RAIN AND FLOODS ON DOUBLE-CROPPING RICE GROWING SEASONS IN HUBEI

利用1961～2008年湖北省双季稻区常规气象站资料,统计计算了双季稻产区在早晚稻生长季的降水量、暴雨量、暴雨日数以及洪涝发生次数,揭示了近50a来双季稻区降水及洪涝的变化特征。结果显示:湖北省双季稻区在早晚稻生长季的降水量都有弱的增加趋势,尤其是鄂东北局部和江汉平原南部;在水稻抽穗扬花至成熟期间,早稻暴雨量大部有不显著的增加趋势,而晚稻则大部为弱减少趋势。早稻生长季内洪涝的发生次数总体呈增加趋势,局部地区严重洪涝发生次数加大;晚稻生长季洪涝总次数有略减少趋势,重度以上洪涝发生很少,但呈略增加趋势。

Based on meteorological precipitation data in double-cropping rice planting areas of Hubei during the period of 1961 to 2008,the change characteristics of rain,rainstorm and flood in early and late rice growing seasons is statistically analyzed.The results show that precipitation in double-cropping rice planting areas during both early and late rice growing seasons expresses a weak increasing trend in recent 50 years,especially in northeastern Hubei and southern part of Jianghan Plain.While the result is different with rainstorm precipitation in each critical growing periods.Rainstorm shows a unremarkable increasing trend in critical growing seasons of early rice,but a weak decreasing trend with late rice.Flood occurrence in early rice growing season has an increasing trend,especially severe flood in part areas,while in late rice growing season,it has a slight decreasing trend,and severe flood happens infrequently but presents an increasing trend in recent years.