一、前言 1983年10月上旬与中旬汉江连续两次出现秋季大洪水,其中上旬洪水为建国以来的最大洪水,丹江口水利枢纽最大入库流量达34200秒立米,按水库未建的情况推算,坝址处最大流量为32400秒立米,仅次于1935年的50000秒立米,为50年来的第二位。这次洪水丹江口水库最大泄量达19600秒立米,下泄流量大于19000秒立米的历28小时,坝前最高水位达160.07米,已远远超过正常蓄水位157米。此时坝下丹江口～皇庄(碾盘山)区间(简称丹～皇区间,下同)又出现了 Foreword In early October 1983 and the middle of the Han River in two consecutive autumn floods, of which floods in early floods since the founding of the largest flood, Danjiangkou water conservancy hub maximum flow of up to 34,200 seconds of legislation, according to the reservoir is not built the situation projections, the dam The maximum flow at the site was 32,400 seconds, second only to 50,000 meters in 1935, the second highest in 50 years. The maximum discharge of Danjiangkou Reservoir reached 19,600 s during the flood and the discharge flow exceeded 19,000 s for 28 hours. The highest water level in front of the dam reached 160.07 meters, far exceeding the normal water level of 157 meters. At this time Danxiakou Dam ~ Huangzhuang (Nian Pan Shan) interval (referred to as Dan ~ Imperial interval, the same below) appeared again