1959-2017年安徽省夏季降水的时空变化及其影响因素研究

【目的】探究安徽省区域水热动态变化趋势,对区域水旱灾害发生的夏季降水时空分布变化特点、分配特征及变化规律进行分析。【方法】利用1959―2017年安徽省16个气象站逐月降水资料,采用气候倾向率法、滑动平均法、Mann-Kendall突变检验法并基于克里金插值法,对安徽省1959-2017年夏季降水的时空分布特征及影响因素进行分析。【结果】研究区年均夏季降水540.1 mm,占年均降水总量45.9%,夏季降水量变幅为275.7~1 137.0 mm;1959-2017研究区年均降水量和夏季降水量总体上都呈增加趋势,其中夏季降水量变化率为23.01 mm/10 a,略高于年均降水变化速率(21.31mm/10a);夏季降水作为年降水极值的重要构成,在1975年存在显著突变点,20世纪70年代末到20世纪90年代中期突变情况复杂多变,存在多个突变年份,突变年份与厄尔尼诺年具有较强关系。安徽省夏季降水与年降水在空间分布上都呈现出南多北少的同步趋势;年降水量呈现237.0~753.2 mm的降水梯度,夏季降水出现426.4~1 045 mm的降水梯度。【结论】安徽省夏季降水变化特点表现为集中性和突变性共存的特点,降水呈现增多趋势是全球气候变暖背景下复杂的水热响应关系以及以厄尔尼诺现象为代表的异常气候事件共同作用的结果;安徽省区域气候过渡性和复杂下垫面地形条件造成了区域降水显著分异。

Study on the Summer Precipitation Spatial-temporal Variation and Influencing Factors in Anhui Province in 1959-2017

【Objective】The objective of this paper is to study the variation trend and dynamic prediction of summer precipitation in Anhui Province.【Method】Based on the monthly precipitation date of 1959-2017 from 16 meteorological station in Anhui province, applying climate tendency rate, moving averaging method, Mann-Kendall method and Kriging interpolation method based on Arcgis10.2, the article explored the spatial-temporal distribution characteristics and influencing factors of summer precipitation in Anhui Province in recent 60 years.【Result】The average annual summer precipitation in the study area was 540.1 mm, accounting for 45.9% of the total annual precipitation, and the summer precipitation variation ranged from 275.7 mm to 1 137.0 mm. In the past 60 years, the average annual precipitation and summer average precipitation in Anhui Province generally showed an increasing trend, with the change rate of summer precipitation being 23.01 mm/10 a, which is slightly higher than the annual average precipitation change rate(21.31 mm/10 a). Summer precipitation was also an important component of the extreme value of annual precipitation, and the summer precipitation in Anhui Province reached the maximum in 1991 and the minimum in 1978. At the same time, there was a significant mutation point in 1975. From the late 1970 s to the mid-1990 s, the mutation situation was complex and changeable, and there were several abrupt years. The years of the mutation points were around El Nino years. The spatial distribution of summer precipitation and the annual precipitation in Anhui Province showed a trend that the precipitation was more in the south and less in the north. The gradient of annual precipitation was from 237.0 mm to 753.2 mm. The gradient of summer precipitation was from 426.4 to 1 045 mm.【Conclusion】The variation characteristics of summer precipitation in Anhui Province were concentrated and abrupt. The increasing trend of precipitation was the result of the complex hydrothermal response under the background of global warming and the interaction of abnormal climate events represented by El Nino phenomenon. The significant differentiation of regional precipitation resulted in regional climate transition and complex underlying surface topographic conditions in Anhui Province.