三峡工程泥沙淤积对重庆港区航运安全的影响与治理措施的探讨

川江为大型山区河流,水量充沛、坡陡流急,较细泥沙不易淤积,河床主要为岩石与卵石所构成,浅滩泥沙冲淤规律为“洪淤枯冲”,年内冲、淤基本平衡。由于水流能量大,浅区短,往往以较少的工程量即可取得良好的整治效果,满足航运发展的需要。三峡工程建成后,库区水流、泥沙运动发生很大变化。在较大范围的常年库区,水深增大,水流减缓,航行条件显著改善。但在变动回水区,天然河道与水库状态交替出现,将对重庆港区航运产生严重的不利影响。本文根据三峡工程泥沙模型的试验,阐述了库尾泥沙淤积发展及其分布规律。并针对存在的问题,从泥沙治理、岸坡整治、炸礁清库等方面进行综合分析探讨,为确保重庆港区航运安全畅通提供了科学对策。

THE INFLUENCE OF SEDIMENT OF THE THREE GORGES PROJECT UPON SAFE SHIPPING IN CHONGQING HARBOR REACH AND APROACH TO CONTROL MEASURES

The Chuanjiang River is a large mountain river with abundant water, steep slope and torrent current, in which finer silt deposites difficulty. The river bed is mainly formed by rock and cobble, and according to the erosion and sedimentation law of choal—"sedimentation in flood season and erosion in dry season", there is the equilibrium of erosion and sedimentation in a year. Better effect under control is frequently gained with less work, and then meets the need of shipping development for the great energy of flow and short shoal zone of the Chuanjiang River. The movement of sediment and flow in the reservoir area will be greatly changed after completion of the Three Gorges Project. The water depth will be increased, the flow will be slowed down and navigation condition will be improved significantly in the wider range of perennial reservoir area. But in variation range of backwater, the alternative presentation of natural channel and reserior state will exert disadvantageous influence upon shipping of Chongqing harbour zone seriously. The paper expounds the sedimentation variation and its distribution pattern of the reservoir rear. Then the paper analyzes and approaches the program on sediment control, bank slope renovation, resevoir clearance, reef blasting and concerning problems comprehensively. Finally a scientific strategy is presented in order to ensure safety and unblocked shipping in Chongqing harbour zone.