摘要
根据长江口南槽 3a中的 2 3次地形实测资料 ,揭示拦门沙航道的季节性冲淤规律及其主要影响因子 ,并利用所获得的经验关系对入海水沙特征年份及洪水、风暴迭加情况下河床的冲淤幅度进行了预报。结果表明 :拦门沙航槽的季节性冲淤变化主要受洪水和风暴控制。在不受风暴干扰的前提下 ,河槽纵向上各点的水深同大通站径流量之间存在负相关关系 ,相关性以径流同落后 1～ 2月的地形之间的关系为最好 ;随着向海距离增大 ,这种“滞后”时间有延长趋势。正常年份径流引起的洪枯季最大冲淤幅度约为 0 .6～ 0 .7m量级 ,特枯水 (沙 )年和特丰水 (沙 )年引起的洪枯季最大冲淤幅度估计分别为 0 .4～ 0 .5m和 0 .9～ 1.0m量级。十年一遇的风暴引起约 0 .4m的淤积。若特丰水 (沙 )年洪水和百年一遇的强台风碰头 ,拦门沙河床的洪枯季冲淤幅度可能达 1.5m左右量级。
Taking the South Passage of Changjiang River mouth as an example, this article examined the extent and controlling factors of seasonal changes in the bed level of the river mouth channel bar. The correlation between the bed level and the riverine discharge was utilized to forecast the possible changes in the bed level under normal and extreme riverborn discharges.The bed level of the channel bar is sensitive to changes in riverine discharge and typhoons. The channel depth is negatively correlated with the river water discharge with a time lag of 1 to 2 months. The range of the change between flood season and dry season in particular years of minimal, normal and maximum river discharges was 0.4～0.5 m, 0.6～0.7 m and 0.9～1.0 m, respectively. An accretion of 0.4 m is likely to be generated by a ten-year-once typhoon.In case of a hundred-year-once storm superposing on an extremely high river flood, the seasonal change in bed level may probably reach 1.5 m.
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2001年第3期258-265,共8页
Resources and Environment in the Yangtze Basin
基金
教育部重点科技项目! (批准号 :980 41〕
国家杰出青年基金!资助项目 (批准号 :4982 5 16 1)
国家九五攻关项目! (批准号 :96 - 92 2
关键词
河床冲淤
拦门沙
径流
台风
长江口
季节性冲淤
change in bed level
river mouth bar
runoff
typhoon
Changjiang River mouth
