四川省气候干湿变化的特征及其影响因子

Characteristics and Influencing Factors of Dry and Wet Climatic Changes in Sichuan Province

为四川农业区划及生产应用提供科学依据,选择1980-2016年四川省32个气象站点逐日气象数据资料,采用Penman-Monteith模型计算各站点参考作物蒸散量和地表湿润指数(SWI),并运用气候倾向率、敏感性系数、气象因子敏感系数贡献率与Arcgis空间插值等方法分析SWI,研究四川省气候的干湿变化特征及其影响因子。结果表明:四川气候总体呈干旱化趋势,东部与南部干旱趋势较大,其余地区均呈湿润趋势;SWI相对1980s、1990s、2000s和2010s 4个年代际呈先逐渐变湿润再逐渐变干旱的过程,其季节差异较大,冬春季呈季节性干旱;敏感性最高的气象因子是日照时数,其次是相对湿度;对SWI贡献率最大的气象因子是相对湿度,其次是日照时数。

The characteristics and influencing factors of dry and wet climatic changes were studied through analyzing surface wet index(SWI)by using climate tendency rate,sensibility coefficient,meteorological factor contribution rate and Arcgis spatial interpolation based on daily meteorological data from 32 meteorological stations to provide the scientific basis for agricultural regionalization and production application in Sichuan.Result:The climate shows an arid tendency in Sichuan overall.The arid tendency in Eastern Sichuan and Southern Sichuan is larger but the climate in other regions presents a wet tendency.The surface wet index(SWI)presents a first gradual moistening and then gradual arid tendency during four decadal periods from 1980s to 2010s.There is a significant difference in SWI among four seasons and seasonal drought occurs in winter and spring.The meteorological factor with the highest sensibility is sunshine duration,followed by relative humidity.The meteorological factor with the highest contribution rate to SWI is relative humidity,followed by sunshine duration.