洪湖分蓄洪区启用的若干问题研究

１９９８年长江供水对沿江大堤及分蓄区都是一场验，同时也使人们对一些老问题的严重性和新问题的紧迫性和加深了认识。本文就洪湖分洪工程存在的问题，特大洪水条件下分洪区启用时的口门位置及其分洪区启用前后的有关重要问题进行了，提出了相应对策。文中涉及的问题对其它分蓄洪也有参考意义。

SOME PROBLEMS RELATED TO THE UTILIZATION OF HONGHU FLOOD DIVERSION AND STORAGE WORKS

The key problems exposed during the period of severe floods occurred in 1998 are discussed and the corresponding strategies are proposed. It is indicated that the Honghu Flood Diversion and Storage Works, as the largest diversion area in the middle Yangtze River, playS an important role in flood prevention in the middle and lower reach of the Yangtze River. However,it is very difficult to be used in the existing condition upon the extreme flood, since there is no primary flood-control works, safety area construction and relevant flood insurance for the people therein. In case that the works the used, the recomended 3 diversion gates, Shangchewan, Luoshan and Longkou,are compared in terms of the effects on the water level decreasing at Chenglinji as well as the possible maximum diversion discharges when assuming a constant water level of 34.40m at Chenglinji. The variation of inflow from the Dongting Lake is also considered as a controlling factor for the selection of the diversion gate. The predicted results from the I-D unsteady flow modle show that Shangchewan is a very good choice, however, Luoshan is another very good alternative when the inflow from the Dongting Lake is relatively large and the now from upper reach of Jianli is relatively small. The interpretations are given in the paper in connection with the observation during the floods in 1998.The longterm objective is believed to escape the large water level under a small discharge owing to the serious deposition in the main stream of the Yangtze River.