江苏弶港盐沼风车河潮沟地貌与动力演化

联合国环境署(1990)在题为“海相环境的状况”的报告中指出，世界人口约一半集中在海岸地区，因而这些地区人口压力巨大，同时受到污染、风暴潮、地面沉降的威胁，以及高地灌溉水资源枯竭的影响；在低地海岸、河滩和湿地，海平面的上升将会给沿岸城市的工农业生产及人民生活带来极其严重的后果。而盐沼-潮沟体系则是淤泥质海岸缓冲、削减波浪-潮流能量的重要地貌系统，对海岸的保护起着至关重要的作用。潮沟常常贯穿盐沼与泥坪(或沙坪)，成为沟通盐沼-泥坪体系物质能量交换的纽带；在淤涨型淤泥质海岸上，细颗粒泥沙被涨潮流沿潮沟输送到盐沼上，结果使盐沼不断向海淤进。而当海平面上升时，盐沼-潮沟系统功能又发生改变，成为削减潮汐能量的“装置”。Pethick(1980，1992)研究了英国Norfolk盐沼潮沟水流的特征，并提出了流速的预报模型；Healey等(1981)在观测中发现了一些与模型不符的情况。本文从地貌和动力方面研究了江苏淤泥质海岸弶港盐沼风车河潮沟的地貌演变与动力演化的关系，以及水动力与地貌因素之间的相互响应机制。

EVOLUTION OF GEOMORPHOLOGY AND HYDRODYNAMICS IN FENGHE CREEK AT JIANGGANG SALTMARSH, JIANGSU, CHINA

This study on the evolution of geomorphology and hydrodynamics in Fengche Creek at Jianggang Saltmarsh, Jiangsu showed that the geomorphologic development of Fengche Creek was mainly controlled by the hydrodynamics. The measured tidal current velocity in the creek in 1996 was only half of that in 1979. The creek bottom has silted up 1.31m due to deposition after the hydrodynamics weakened. An obvious feedback mechanism exited between the creek geomorphology and the hydrodynamics. The geomorphology factors, i.e., the slope of the creek bottom and the elevation, had impact on the hydrodynamics processes. For example, several velocity surges were observed in the tidal creek. These velocity surges can bring a mass of tidal water and sediment onto the saltmarsh surface, and strongly influence the evolution of the tidal creek and the upper saltmarsh. The grain size of surfacial sediments in the creek becomes finer from its mouth to the headwater; and the suspended sediment concentration at the mouth was higher.