湖南省农业水灾演变特征及预测分析

Evolution characters and predictive analyses of the agricultural flood disaster of Hunan Province

基于湖南省1950-2013年农业水灾资料,运用数理统计、移动平均法等方法,分析了农业水灾的演变特征。结果表明,近64年来以农业轻灾频率最高,重灾和特大水灾多发生在1982-2005年间,约4-5年一次。农业受灾率异常指数于1955-1963年、1965-1968年、1970-1979年、2004-2013年出现4个低谷值,分别为-0.773 6、-0.751 9、-0.817 2、-0.793 7;于1980-1984年、1987-1999年、2001-2004年出现3个高峰值,分别为0.845 0、2.150 4、2.316 5。农业成灾率异常指数于1950-1953年、1955-1987年、1988-1990年、1996-1998年、2000-2001年、2008-2013年出现6个低谷值,分别为-0.657 1、-0.747 8、-0.262 3、-0.600 9、-0.324 8、-0.327 6;于1953-1955年、1987-1989年、1990-1995年、1996-1998年、2001-2004年出现5个高峰值,分别为0.757 8、1.888 2、1.100 7、2.730 1、2.862 4。2005至2013年受灾率和成灾率两异常指数呈同步下降趋势。并运用最优气候均态模型预测结果显示,2018年和2023年可能发生农业重水灾,其余年份的受灾和成灾情况均为轻灾。

Based on the agricultural flood data （1950-2013） of Hunan province, evolution characters of the agricultural flood disaster are analyzed by the mathematical statistics analysis and moving average method. The results are： In the last 64 years, the light flood disaster has accounted for the most of the flood disaster, and heavy and extra heavy flood disasters happened most frequently during 1982-2005 which appeared about every 4-5 years. The abnormal index of the agricultural disaster-affected rate respectively equaled -0.773 6, -0.751 9, -0.817 2 and -0.793 7 during 1955-1963, 1965-1968, 1970-1979 and 2004-2013, which were the four lowest values. The three highest values of this rate were 0.845 0, 2.150 4 and 2.316 5 which appeared during 1980-1984, 1987-1999 and 2001-2004. The abnormal index of the agricultural disaster-destroyed rate respectively equaled -0.657 1, -0.747 8, -0.262 3, -0.600 9, -0.324 8 and -0.327 6 during 1950-1953, 1955-1987, 1988-1990, 1996-1998, 2000-2001 and 2008-2013, which were the six lowest values. The five highest values of this rate were 0.757 8, 1.888 2, 1.100 7, 2.730 1 and 2.862 4 which appeared during 1953-1955, 1987-1989, 1989-1997, 1997-2000, 2001-2004 and 2006-2008. Both the abnormal index of the agricultural disaster-affected rate and disaster-destroyed rate synchronously decreased in 2005-2013. The predict results shows that the agricultural heavy disaster will probably appear in 2018 and 2023 and the light disaster may appear in other years.