1960—2014年福建省极端气候事件时空特征及变化趋势

Spatio-temporal characteristics and trends of extreme climate events across Fujian Province,during 1960-2014

为分析福建省极端气温和降水事件的时空特征及变化趋势,基于区域内23个气象站点,1960—2014年逐日降水、最高气温、最低气温和平均气温资料,采用线性倾向估计、最小二乘和Mann-Kendall非参数检验等方法进行研究。结果表明:1)在区域尺度下,冷气温指数呈降低趋势,其中冷持续指数和冷夜指数下降趋势较显著;而暖气温指数(作物生长期、暖夜天数和暖昼天数)均呈显著增加趋势;2)过去55年中,除最大持续降水时间(CWD)外,总降水量和其余极端降水指数均呈增加趋势;3)空间特征上,极端气温指数的上升或下降趋势在全省区域内基本一致,而极端降水指数区域差异明显,上升倾向率较高的站点主要分布在沿海地区。极端冷指数呈下降趋势,极端暖指数呈上升趋势;降水量和极端降水增加而CWD减少,表明强降水在时间上更集中,该区域洪涝和局部干旱的风险加大。研究结果可为区域水资源适应性管理、水土保持及农业管理提供参考依据。

[Background] The accelerated water circulation has changed regional hydrological and meteorological elements,which can lead to more frequent flood,drought and soil erosion,and further influence the ecological environment. It is well known that extreme climate events are exhibiting an increase trend in most of the land areas. The increased intensity and frequency of extreme climate events have severe impacts on the human society and natural ecosystem. Therefore,it is of great significance to understand its recent changes in different regions. Fujian Province is located in the southeast coastal region of China with rapid urbanization,and in which there are frequent flood and drought disasters related to extreme climate events. [Methods]This paper analyzed the variability of extreme temperature and precipitation indices in Fujian Province during the period of 1960 to 2014, based on 23 meteorological stations covering daily precipitation, daily maximum temperature, daily minimumtemperature and daily average temperature datasets from 1960-2014. The statistic methods including linear trend estimate method,least squares estimation and Mann-Kendall trend analysis method were employed to analyze these indices. [Results] The cold temperature index showed a decreasing trend.The cold index and cold night index showed significant decrease trends,but the heating temperature index（ the crop growth period,warm night days and warm days） showed significant increase trends at the regional scale. Over the past 55 years,with the exception of the continuous wet days,all the extreme precipitation indices showed an increasing trend. In the spatial characteristics,the increase or decrease trends of the extreme temperature index were similar over the Fujian Province. Noting that the extreme warming indices had a significant upward trend in the whole region,and the regional differences of extreme precipitation index were obvious that the stations having significant increase trends were mainly distributed in the coastal areas. [Conclusions] All the extreme cold indices showed a decrease trend while the extreme warm indices showed an increase trend. The stations with sharp increasing trend of extreme cold index were mainly distributed in the northwest and northeast areas,and the extreme warm indices had significant upward trend across the whole region. The regional difference of extreme precipitation indices was relatively obvious,and the stations with sharp increase rates were mainly located in the coastal areas. As for the variability in precipitation,the total precipitation and precipitation extremes tended to increase while the wet days tended to be less,which suggests that the extreme precipitation events are more concentrated in time. Therefore,the risk of flood and local drought events increased in the region,and adaptive measures for mitigation of climatic disasters and water resources management should be considered in Fujian Province.