Mechanisms underlying the dynamic evolution of an open-coast tidal flat-creek system: Ⅱ: influence of tidal range
摘要
To explore the initiation and development of tidal creek network driven by tidal currents, an experimental physical model was established based on the prototype of a silt-muddy tidal flat-creek system on the Jiangsu coast. The evolutional process was simulated with an initially gentle bed slope of about 1%. The movement of flow and sediment, as well as the influence of tidal range on tidal creek development, was analyzed. The results indicated that tidal creek development was influenced by the bed slope variation. For the cases of uniform bed slope, the connection of neighboring tidal creeks, rather than headward erosion as shown by previous studies, resulted in the development of tidal networks. A strong flow and sediment movement occurred at the early flood and the late ebb stages, and sediment movement was most active in the mid-intertidal flat. Tidal range had little influence on the overall pattern formation and the structure of tidal networks. The relationship between the mean drainage path length and the sub-basin area generally followed a power-law function. Tidal networks approached a dynamic equilibrium state earlier under larger tidal ranges which contributed more to the development of the tidal creek widths.