基于SPEI指数的淮河流域干旱时空演变特征及影响研究

运用淮河流域149个气象站1962—2016年逐日气温、降水资料以及历史旱情资料,基于SPEI、EOF和M-K等方法分析淮河流域的干旱时空特征,研究干旱的时空演变规律并揭示其对农业生产的影响。结果表明:(1)基于SPEI得到的干旱频次与受灾、成灾面积的相关性通过了0.1的显著性水平检验,表明SPEI在淮河流域具有较好的适用性;(2)淮河流域干旱发生时间差异明显,干旱次数呈现波动变化,发生重旱和特旱次数占总干旱的比重是20.0%,其中重旱和特旱在1960s比重最大(24.8%),其次是2010s(15.8%),在1980s比重最低(10.0%);(3)干旱的空间分布差异大,淮河流域干旱频率在27.76%—36.04%之间,西北部和东南部发生干旱强度较西南部、东北部及中部低;(4)淮河流域总体呈干旱化的趋势,从中部到四周呈现由高到低递减的趋势变化,且空间模态表现为全区一致型、南北相反型和东西相反型。

Temporal and spatial characteristic of drought in Huai River Basin based on standardized precipitation evapotranspiration index

The daily temperature, precipitation of 149 meteorological stations and historical drought disaster in the Huai river basin from 1962 to 2016 were analyzed based on Standardized Precipitation Evapotranspiration Index (SPEI), Empirical Orthogonal Function and Mann-Kendall method. In this study drought evolution were analyzed and revealed the impact of agricultural production in the Huai river basin. The results showed that:(1) The correlation between the number of droughts and drought-affected area at the 0.05 significance level, indicating that the SPEI has an excellent suitability in the Huai river basin. (2) The drought time was significantly different and drought frequency was obvious fluctuation in the Huai river basin. The most of severe drought and extreme drought is the largest in 1960s (24.8%), followed by 2010s (15.8%) and lowest in 1980s (10.0%). (3) The spatial distribution of drought has much difference. The drought severity was change between 27.76% and 36.04% in the Huai river basin. The drought severity in the northwest and southeast is lower than that in the southwest, northeast and central regions. (4) The results showed that trend of regional drought had a tendency towards drought conditions, which was the decreasing from the middle to the surroundings in the Huai river basin. The principal modes of our results indicated obvious variation and consistent.