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在放射性核素~(210)Pb测年分析的基础上,综合运用沉积物粒度、沉降板测量及遥感影像解译等方法,对如东县紫菜养殖前后潮滩沉积环境尤其是潮滩地貌的冲淤变化进行了初步探讨。研究结果表明:在以年计算的长时间尺度上,紫菜养殖对潮滩地貌的冲淤不会产生明显影响,紫菜养殖区沉积物的沉积速率符合自然状况下沉积物的沉积速率,这一变化规律与紫菜养殖区沉积物粒径变化规律相一致。但在紫菜养殖期间,由于网帘、竹竿的架设及紫菜对水动力的阻滞作用,会大大加速该区域潮滩的沉积,此期间紫菜养殖区呈淤积状态;而一旦进入非紫菜养殖期间,潮滩在水动力作用的冲刷下又将恢复到原来的自然状态,滩面保持冲淤平衡,这一变化规律与沉降板泥沙厚度测量及遥感影像分析结果互为印证。因此,潮滩紫菜养殖本身并不会对养殖区潮滩地貌的冲淤变化产生明显的影响,但养殖紫菜期间所引起的频繁人类活动,在一定程度上会加速该区域低潮滩的侵蚀。
Based on the dating of ~ (210) Pb and radionuclide ~ ~ (210) Pb, the depositional environments of tidal flat before and after the laver culture in Rudong County, especially the tidal flat landform, were comprehensively analyzed by sediment particle size, settlement plate measurement and remote sensing image interpretation. Erosion and deposition changes were discussed. The results showed that the larvae culture had no significant effect on the erosion and deposition of the tidal flat landforms on the long-term scale calculated in years. The deposition rate of the laver culture zone accords with the deposition rate of the sediments under the natural conditions. The law is consistent with the variation of sediment particle size in laver culture zone. However, during the cultivation of seaweed, the deposition of tidal flat in this area will be greatly accelerated due to the setting of net curtain and bamboo pole and the retardation effect of seaweed on hydrodynamic force. During this period, the seaweed farming area is in a siltation state; and once it enters the non-seaweed cultivation period, Under the erosion of hydrodynamic action, the tidal flat will return to the original natural state again, and the beach surface will maintain the balance of scouring and silting. This variation confirms with the result of sediment thickness measurement and remote sensing image analysis. Therefore, the tidal flat seaweed farming itself will not have obvious impact on the erosion and sedimentation of the tidal flat landforms in the aquaculture area. However, frequent human activities caused during the cultivation of seaweed will speed up the erosion of the low tide beach to a certain extent.