1976-2015年中国主要农业气象灾害的变化特征

根据1976-2015年受灾、成灾和绝收面积等统计数据,计算中国主要农业气象灾害包括洪涝、干旱、风雹和低温灾害的受灾率、成灾率、绝收率和损失率,并对其变化趋势、灾害损失和灾害等级的变化特征进行分析.结果表明:(1)总体上,1976-2015年中国主要农业气象灾害的受灾率呈显著减小的趋势,而成灾率和绝收率变化趋势则不显著.干旱与农业气象灾害总体变化趋势相一致;洪涝受灾率、成灾率和绝收率存在阶段性的变化特征,1986-2005年各项均值最大;风雹灾害下降趋势显著,受灾率、成灾率均显著减小;而低温灾害各项指标的年代均值逐渐增加.(2)研究期内四大灾害总体损失率的上下限呈先增加后减小的趋势,平均灾害损失率为7.1％～15.7％.洪涝和干旱灾害损失率的上下限变化趋势与农业气象灾害总体一致,其平均损失率分别为2.0％～4.2％、3.8％～8.6％;而风雹灾害损失率的上下限呈减小的趋势,平均损失率为0.8％～1.7％;低温灾害损失率的上下限呈增加趋势,平均损失率为0.5％～1.1％.(3)研究期间洪涝重灾发生次数最多,为突发性灾害;干旱、风雹中灾和重灾发生次数之和最多,为常态性灾害.

Characteristics of Agricultural Meteorological Disasters in China from 1976 to 2015

Based on the statistical data from 1976 to 2015,the disaster rate,loss rate and levels of major agricultural meteorological disasters were calculated and analyzed,including flood,drought,hail and low temperature.The results revealed that,(1) in general,disaster-induced rate of major agricultural meteorological disasters decreased from 1976 to 2015 in China,while the trend of disaster-affected rate and no harvest rate were not significant.Drought was almost the same as the overall trend.The flood-induced rate,flood-affected rate and no harvest rate showed the characteristics of stage change,and the average of those three indicators from 1986-2005 was the largest.The hail falling trend was remarkable,and disaster-induced rate and disaster-affected were significantly reducing.However,the low temperature disaster rate of the 10-year average gradually increased.(2) The upper and lower limits of the overall loss rate increased first and then decreased,with an average loss rate of 7.1％-15.7％.Drought and flood showed the trends of increased first and then decreased,hail showed decreasing trend,while low temperature showed increasing trend.The average loss rate of drought,flood,hail and low temperature were 2.0％-4.2％,3.8％-8.6％,0.8％-1.7％ and 0.5％-1.1％ respectively.(3) The number of times of flood at severe level was the most,thus flood was a sudden disaster.Drought and hail were normal disasters with a high frequency.