湖北省降水及旱涝时空分布特征分析

Analysis of Spatial and Temporal Distribution of Precipitation and Drought in Hubei Province

为更加全面地了解湖北省降水和旱涝时空分布特征,基于湖北省30个雨量站资料,采用M-K趋势检验、Morlet小波、Z值法及EOF等分析计算方法,对全省1960—2013年降水变化显著性、周期性及空间分布变化进行了研究,并分析了湖北省单站旱涝、区域旱涝等级、空间旱涝分布及30个站点旱涝Z值空间分布模态。结果表明:全省近50年降水量整体呈略微减少的趋势,但减少趋势不显著,降水倾向率为2.92 mm/10 a,空间上呈现东南部和西南部较多,且中东部地区降水呈增加的演变趋势;在此驱动下,全省呈现出旱涝交替频发,东南部易发生涝灾,西北地区易发生旱灾的整体特征;且通过旱涝Z值的EOF正交分解分布图发现,全省旱涝分布呈一致型、西北和东南方向相反型和自西北向东南呈"三明治"型的规律,其贡献率分别为50.23%,16.14%,5.59%。

To more comprehensively understand the spatial and temporal distribution characteristics of precipitation and drought and flood in Hubei Province, based on the data of 30 rainfall stations in Hubei Province, the M-K trend test, wavelet analysis, Z value and EOF method were used to analyze and calculate the data. The variation of rainfall, periodicity and spatial distribution in the 1960—2013 years of the province were analyzed. The regional drought and flood level, the spatial distribution of drought and flood and the spatial distribution pattern of drought and flood Z value in 30 stations were also analyzed in Hubei Province. The results indicated that the precipitation lecreasing in the last 50 years had been decreasing slightly. But the decrease trend was not significant. The precipitation decreasing tendency was 2.92 mm/decade. There was more precipitation in the southeast and southwest and the trend of precipitation increased in the eastern and central regions. In this drive, the alternating droughts and floods occurred frequently in the province. The southeast was prone to flooding and the northwest region was prone to drought. According to the EOF orthogonal decomposition distribution map of drought and flood Z value, there were three types of distribution of drought and flood in Hubei Province, which was uniform on provincial scale, opposite in the northwest and southeast directions, and ‘sandwich’ type from northwest to southeast. Their contribution rates were 50.23%, 16.14%, 5.59%, respectively.