Ravensrodd Consultants Ltd., 6 Queen's Drive, Taunton, Somerset TA1 4XW, UK.
Mar Pollut Bull. 2010;61(1-3):21-36. doi: 10.1016/j.marpolbul.2009.12.011. Epub 2010 Feb 12.
The Severn, a hypertidal, high turbidity estuary, has a bed largely stripped of unconsolidated sediment. Its inter-tidal zone is mainly mudflats, the universal erosional trend of which is now proven. These are a source for sub-tidal mud accumulations in Newport Deep, much of Bridgwater Bay, less so in Bristol Deep and Cardiff Roads. The main estuary turbidity maximum is dominated by its exceptional turbidity and the cycling of this on two tidal timescales. It is the means to exchange fines between sources and sinks. It shows discontinuities in three planes - lutoclines, suspended sediment fronts and slug flow. Much of the estuary is verging on or actually barren. It has been designated under EU legislation for its fine sediment-induced naturally-depauperate nature. This is invalid as it is complicated by large scale ecosystem collapse due to climate change. Building a Cardiff-Weston barrage would induce a large rise in faunal abundance and biodiversity.
塞文河是一条高潮汐、高浊度的河口，其床底大部分没有松散的沉积物。其潮间带主要是泥滩，现在已经证明了其普遍的侵蚀趋势。这些泥滩是纽波特深海、布里奇沃特湾大部分地区、布里斯托尔深海和加的夫路(sub-tidal mud accumulations)的泥沙来源。主要河口的最大浑浊带主要由其异常的浑浊度和这种浑浊度在两个潮汐时间尺度上的循环所决定。它是在源和汇之间交换细颗粒物质的手段。它在三个平面上显示出不连续性——富营养层、悬浮泥沙前缘和块状流。河口的大部分地区已经接近或实际上已经荒芜。根据欧盟立法，该河口因细泥沙导致的自然贫瘠而被指定为保护区。由于气候变化导致大规模生态系统崩溃，这一规定是无效的。建造加的夫-韦斯顿水坝将导致动物群数量和生物多样性的大幅增加。
