基于多源降雨的广西季节性干湿演变特征与未来趋势

摘要

The seasonal meteorological dry and wet evolution of Guangxi,which referred to frequency,range, intensity,temporal spatial variation and future trend adopted by precipitation anomaly percentage,DEOF and R/S methods,were analyzed in this paper over the past 65 years,based on APHRODITE and TRMM rainfall data. The results showed that:(1)Annual dry/wet frequency decreased gradually from southeast to northwest of Guangxi, however,seasonal dry/wet frequency presented significant differences in spatial distribution within a year. The affected range and intensity of dry/wet varied alternately and fluctuated both in annual and seasonal scales,but their variation were significant differences among these time scales. ( 2 )The dry-wet temporal evolution emerged alternating strong and weak oscillations in all annual and seasonal scales,and the spatial variation declared different patterns,such as:the reverse type of southeast-northwest in the yearly scale and in winter,the uniformity type of whole region in spring,the opposite type of north and south in summer,and the reverse type of east and west in autumn.(3)The future rainfall in Guangxi would increase significantly in summer and in the annual scale,with slight decrease in spring,autumn and winter. This research would be an important scientific basis for further wet and dry evolution warning and dry-wet disaster prevention in Guangxi.%基于高时空分辨率的APHRODITE和TRMM降雨数据,采用降水量距平百分率、DEOF及R/S分析等方法,对近65年来广西季节性气象干湿演变的频率、范围、强度、时空分异及未来趋势进行了分析.结果表明:(1)广西年湿润和年干旱频率均呈现从桂东南向桂西北逐渐递减的分布特征,而年内不同季节的湿润和干旱频率空间分布差异显著;湿润与干旱的影响范围和强度在年、季尺度上均呈交替出现且增减波动的变化特征,但各自的变化差异显著.(2)广西干湿演变存在不同年、季周期的交替强弱振荡,其空间特征主要表现为年、冬季的东南-西北相反型,春季的全区一致型,夏季的南北相反型,秋季的东西相反型.(3)广西未来降雨量的增强趋势在年、夏季显著;而在春、秋、冬季节总体一般或略呈减弱趋势.上述研究成果可作为进一步深入开展广西干湿演变预警与水旱灾害防治的重要科学基础.