福建省枇杷冻害时空变化特征及其危险性评估

Spatial and temporal variation characteristics and risk evolution of frost damage of loquat in Fujian Province

为了研究福建省枇杷冻害发生规律以科学应对气候变化对枇杷种植造成的风险,基于1971—2020年福建省66个站点逐日最低气温观测数据,采用回归分析、线性趋势分析、熵权法和转移矩阵等方法,对1971—2000年和2001—2020年两个时段福建省枇杷花期和幼果期各等级冻害的发生频次和危险性等级的时空演变规律进行分析。结果表明:1)福建省枇杷花期和幼果期冻害整体明显减少,花期冻害减幅为0.17次·(10 a)^(-1),幼果期减幅更明显,为0.57次·(10 a)^(-1)。冻害的空间范围也有所缩小,但不同年代间波动幅度较大,个别年代存在大范围严重冻害风险。2)各等级冻害发生频次的气候倾向率以减少为主,空间分布特征相似,呈现明显减少趋势的站点和区域主要分布在南平市、宁德市和三明市。3)在冻害危险性等级的时空变化上,相较1971—2000年,2001—2020年轻度危险区扩大至南平市中部的中低海拔地区,中度危险区扩大至三明市西部和南平市中北部的中海拔地区,重度以上危险区范围明显减小,主要位于三明市西部、南平市西北部、宁德市西部及内陆地区的中高海拔地区。在明显变暖背景下,福建省枇杷冻害的危险性时空分布发生较大变化,中西部的中低海拔地区可根据实际情况小幅扩大枇杷种植规模。

In order to identify the occurrence pattern of loquat frost damage in Fujian Province and scientifically respond to the risk of loquat planting in the background of climate change,we analyzed the temporal and spatial evolution characteristics of frost damage frequency and risk levels at the flowering and young fruiting stages of loquat in Fujian Province during the periods of 1971-2000 and 2001-2020,based on daily minimum temperature observation data of 66 stations during 1971-2020,and by using regression analysis,linear trend analysis,entropy weighting method and transfer matrix approaches.The results are as follows:1)The frequency of frost damage in both the flowering and young fruiting periods of loquat presented a significantly decreasing trend,the decline was more pronounced during the young fruiting stage(0.57 times per decade)compared to the flowering stage(0.17 times per decade).The spatial scope of frost damage was also reduced,but fluctuations in different decades were significant,and in some individual decades there was widespread severe frost damage.2)The climatic trend rate of the frequency of frost damage at all levels exhibited a predominant decrease,with similar spatial distribution characteristics.The areas and stations with significant reductions were primarily located in Nanping City,Ningde City,and Sanming City.3)Concerning the spatial and temporal variations of frost damage risk levels,the area of mild risk expanded to the middle-low altitude regions of central Nanping,while the moderate risk zone extended to the middle-altitude areas of the western Sanming and the north-central Nanping from 2001 to 2020 compared to the period of 1971-2000.The range of severe and above risk zones significantly decreased,primarily affecting western Sanming and Ningde and the northwest of Nanping and inland mid-altitude regions.With the backdrop of significant warming,the spatial and temporal distribution of frost risk of loquat in Fujian Province has undergone considerable changes,and in the central and western mid-low altitude areas of loquat cultivation scale can be slightly expended based on actual conditions.