广东农业水灾的年际分布规律及重灾年份预测

Interannual Distribution and Prediction of Agricultural Flood in Guangdong Province

水灾是广东省最严重的农业自然灾害之一,几乎年年都有发生。广东农业水灾的受灾率异常指数和成灾率异常指数的变化规律揭示:过去55年间,农业水灾具有明显的波动性与阶段性,大致以5年为尺度,轻重灾期交替出现;受灾率与成灾率具有同步性,在重灾期尤为明显;1980年以来灾情更为严重,成灾率、受灾率、重灾几率都较大。根据异常指数的变化,建立起农业水灾灰色灾变预测模型,进行重灾预测。结果表明,今后20年将出现4个重灾年份,分别在2007-2009年、2012-2014年、2017-2019年和2023-2025年。

Flood is one of the severest agricultural natural disasters in Guangdong Province. The disaster almost takes place every year and often causes great economic losses. The variation of anomalous indices of light and heavy agricultural floods reveals that： during the past 55a, floods took on fluctuant and staggered characteristics and reap- peared in a cycle of about 5a, light and heavy agricultural floods appeared alternatively; affected area ratio and suf- fering area ratio were coincident, that was obvious especially in the great disaster periods; the situation of disasters have become severer since 1980, with the greater affected area ratio, suffering area ratio and heavy flood ratio. A grey system prediction model is established according to the changes of anomalous indices of flood-affected area ratio and flood-suffering area ratio. The result shows that there would be four periods of heavy floods in the coming 20a, they would be. resoectivelv, those of 2007 - 2009,2012 - 2014,2017 - 2019 and 2023 - 2025.