雷州市“十年九旱”分析及未来干旱趋势

Analysis of the Phenomenon of Predominantly Dry Climate in Leizhou and Drought Tendency in the Future

选取雷州气象站1961—2020年降水量、相对湿度、日照时长、平均温度等资料,分析了近60年雷州市降水和干燥度的气候特征。结果表明:雷州市60年间有38年年降水量小于常年平均值,有18年干旱级别为半湿润,有2年干旱级别为半干旱。年降水量和干燥度指数年代际干旱变化愈加明显,近10年中干旱年份有8年。未来2年干燥度指数都大于1,水分支出大于收入,易发生干旱。

The data of annual rainfall amount,relative humidity,sunshine duration and average tem⁃perature for a meteorological station in Leizhou are used to analyze the climatological characteristics of rain and dryness in the city over the 60 years studied.The results are shown as follows.For the city of Leizhou,38 out of the 60 years studied have less⁃than⁃average annual rainfall amount,18 years observe moderately wet conditions,and two years report moderately dry conditions.The interdecadal variations of annual rainfall amount and an aridity index are increasingly significant so that eight out of the recent 10 years experience droughts.For the two years to come,the aridity index is larger than 1,suggesting the output of moisture lar⁃ger than its input and a greater chance for drought to take place.