ENSO事件对红水河龙滩站径流的影响分析

Influence Analysis of ENSO Events on the Runoff of Longtan Dam in Hongshui River

用多元ENSO(厄尔尼诺/南方涛动)指标,分析厄尔尼诺和拉尼娜事件对径流的影响。月径流量数据采用天峨水文站1950年~1997年共48年汛期(5月~10月)径流资料,结合美国国家环境预报中心(NCEP)和美国国家大气研究中心(NCAR)的逐月MEI指数分析红水河龙滩站来水规律。结果显示,龙滩站在汛前或汛期极强/强拉尼娜事件减弱期对应汛期流量呈放大趋势概率大,反之流量呈减少趋势概率大;在极强厄尔尼诺事件年汛期来水总量年际差异巨大,厄尔尼诺事件与流量关系并不总是保持一致,一般情况下厄尔尼诺事件年入汛偏晚概率大。

The multiple ENSO index are used to analyze the influences of E1 Nino and La Nina events on the runoff of Hongshui River. The flood season runoff data （from May to October of year） from 1950 to 1997 of Tian＇e Hydrological Station and NCEP/ NCAR monthly MEI index are used to analyze the flow law in Longtan Dam of Hongshui River. The results indicate that, （a） the flood flow in Longtan Dam has a high probability to increase if the very strong or strong La Nina events weaken before or in flood season, and on the contrary, the flood flow has a high probability to decrease; and （b） the total water flows between very strong E1 Nino years have a huge different, the relationship between E1 Nino events and flow is not always consistent, and the probability of later flood season is high in E1 Nino year.