湖北省近45年降水气候变化及其对旱涝的影响

Analysis of Precipitation Characteristics in Hubei Province and Their Influence on Flood/Drought in the Last 45 Years

从气候倾向率、旱涝倾斜度以及强降水过程次数与强度等方面,对湖北省72个气象台站近45年雨量观测资料及来自于中国农业部信息中心网站洪涝干旱受灾面积等数据进行了分析。研究结果表明:近45年来,随着全球气候变化,湖北东部,尤其是江汉平原东南部的年雨量呈增加趋势,而年降雨天数有减少的趋势;年雨量的增加主要是大雨或强降水增多造成的;湖北省强降水过程及其中心强度呈增多和加强趋势。雨量增多、雨强加大、围湖造田、江河水位高出江汉平原地表以及江汉平原自然下沉等因素加大加快了旱涝灾害程度与频率,应当引起当地政府的高度重视。

Abstract： The rainfall data, which were accumulated from the 72 meteorological stations of Hubei Province from 1960 to 2004, and the data on the drought-stricken and flood-stricken area, which were published on the webpage from the Ministry of Agriculture of the People＇ s Republic of China （zzys. agri. gov. cn）, are analyzed and discussed. The investigation is based on following several aspects of climate, for example the climatic tendency, the skewness of drought and flood as well as the frequency and intensity of the heavy precipitation occurrence. It can be found that in the las/t 45 years the annual rainfall amounts have a strong increasing trend in the east of Hubei Province, especially in the southeast of the Jianghan Plain, while the annual rain days are decreas- ing. The increase of the rainfall amounts is mainly result from increasing of the heavy rain or rainstorm. At the same time the intensity and the frequency of durative heavy precipitation events increase also in this region annually. The analysis on the relationship between the drought-stricken or flood-stricken area and the skewness of drought or flood indicates that climate disasters result mainly from unbalanced spatial and temporal distribution of precipitation. Furthermore all these factors, such as the increase in rainfall amount and intensity of rainfall, the decrease in lake area, the natural sinking of the Jianghan Plain, etc. , quicken the intensity and frequency of drought or flood, on which the local governments should focused.