近十年来台风诱发长江口航道骤淤的初步分析

台风诱发航道骤淤已成为长江口航道淤积的主要表现形式之一,一定程度上威胁长江口航道的安全运行和上海国际航运事业的发展。根据现场实测资料,初步分析了近十年来多次台风期长江口北槽航道骤淤变化特点和规律,探讨了台风诱发北槽航道骤淤的主要影响因素及其内在机理,并提出了防治航道骤淤的有关建议。结果表明,每年台风造成的航道骤淤量在200～800万m3左右,对航道年回淤总量的贡献率在4%～50%之间不等;航道骤淤程度会随航道维护水深的增加而有所增强;航道骤淤分布呈时间和空间均相对集中的特点。分析还表明,台风诱发北槽航道骤淤分布与长江口深水航道治理工程建设引起的水沙动力和河床环境变化是相适应的,而较大的航道骤淤量还与台风期间泥沙来源种类的增加有关。

Preliminary analysis of typhoon-induced sudden sedimentation in navigation channel in Yangtze Estuary over last decade

Typhoon-induced sudden sedimentation in navigation channels is a threat to the safe operation of the Yangtze Estuary waterway and the development of Shanghai International Shipping Center to some extents.Based on the measured field data,the characteristics and law of typhoon-induced sudden sedimentation in navigation channels of the North Passage in recent 10 years are analyzed,the main factors and internal mechanism of sudden sedimentation in the waterways are discussed,and some suggestions of sudden sedimentation prevention are made.The study shows that the amount of sudden sedimentation caused by typhoons is between two and eight million m3 a year,its contribution to the total annual channel deposition ranges from 4% to 50%,and the sudden deposition intensity by typhoons is strengthened with an increase of the navigation channel water depth.The sudden sedimentation distribution in the North Passage waterway is relatively concentrated in time and space.The analysis also shows that the typhoon-induced sudden sedimentation in the North Passage adapts to the changes of water,sediment and bed deformation caused by the Yangtze Estuary Deepwater Channel Regulation Project,while the large amount of sudden sedimentation also has to do with the increase of sediment sources during the typhoon in the Yangtze Estuary.