王英水库灌区水旱交替特征分析

Analysis on Characteristics of Alternate Drought and Flood in the Irrigation District of Wangying Reservoir

基于咸宁、阳新、王英3站多日降水资料,采用长周期旱涝急转指数(简称LDFAI指数)和短周期旱涝急转指数(简称SDFAI指数)作为研究方法,分析王英灌区水旱交替发生规律及变化过程,并探讨了旱涝急转对农业生产造成的影响。研究结果表明:咸宁站和王英站旱涝急转变化的规律较为一致,旱涝急转事件发生的频率分别为4.17 a/次和4.44 a/次,随时间的增加,两站旱涝急转发生频率增加;咸宁站由涝转旱为主导逐渐转向以旱转涝作为主导,而王英站高LDFAI年和低LDFAI年交替出现,无明显主导;阳新站旱涝急转现象主要集中在1996年之前,1997年后LDFAI指数变化趋于平缓;严重的水灾和旱灾年的旱涝急转指数均较高,LDFAI指数绝对值越高的年份,其农业受灾面积越广。

Based on the daily precipitation data of the meteorological station of Xianning,Yangxin and Wangying, it took the Long-cycle Drought-Flood Abrupt Alternation Index( short for LDFAI Index) and Short-cycle Drought-Flood Abrupt Alternation Index( short for SDFAI Index) to analyze the rule and course of flood and drought alternation which happened in the Irrigation District of Wangying Reservoir, exploring the influence which flood and drought alternation had on agricultural production. These results were as follows: The changing rule of flood and drought alternation of Xianning Station was in accordance with Wangying Station,with alternation frequency of 4. 17 year / time and 4. 44 year / time, respectively; Moreover, alternation frequency of the two station increased with the passing of time. Transformation from flooding to drought in the Xianning Station which occupied the major position replaced by transformation from drought to flooding gradually,while years of high LDFAI and low LDFAI alternated without obvious leading. Phenomena of flood and drought alternation of Yangxin Station mostly appeared before 1996, after that, changing of the LDFAI Index turned to be mild. The LDFAI Index was higher in severe flood years and drought years than normal years, besides,the higher the LDFAI Index was,the lager agricultural disaster area was.