Sediment transport in the southeastern Amazon coastal zone (SACZ) is substantially affected by tidal asymmetry, seasonal variation of the wind and wave regime and especially rainfall (i.e., river discharge). The regional climate and geological configuration have resulted in numerous estuaries and large mangrove-covered coastal plains that partially divide the estuarine basins, which are connected by tidal channels. Based on the investigation of the Furo Grande tidal channel, we assess the relevance of connectivity on the sediment transport and evolution of the ∼8000 km² SACZ mangrove belt. Extensive sedimentologic and bathymetric surveys, as well as hydrodynamic measurements including water level, water and sediment flow, and physical-chemical characteristics of the water, were undertaken at different seasonal periods. Water-level variation along the channel shows that sediment-transport convergence (STC) tends to be formed within the connecting channel, as the tide propagates from both ends. Morphologic and sedimentologic results show the accumulation trend of fine sediments within the STC zone, and this is relevant for mud retention and further delivery to the mangrove plains, which may eventually lead to channel-connection closure. Despite the STC, results also show that there is an important net flux of suspended sediments between estuaries through the studied channel. However, the connected estuaries of Taperaçu and Caeté have substantial differences regarding riverine discharge, and thus estuarine processes, tidal propagation and sediment transport. Bottom sediments and morphology reflect long-term trends and show STC migration towards the Taperaçu as a result of substantially smaller fluvial discharge in that estuary, and therefore higher sediment accumulation rates, compared to the Caeté estuary. The migration of the STC prevents the closure of the connection, and its maintenance preserves these channels as sediment-flow conduits between estuaries. The connectivity is a key process to redistribute mainly muddy sediments along this coastal sector, which helps to explain the evolution and maintenance of the relatively homogeneous and widespread progradation of mangroves along the SACZ, with uneven mud supply.

亚马逊东南沿海地区（SACZ）的泥沙运移受到潮汐不对称性，风浪状况的季节性变化以及降雨（即河流流量）的极大影响。区域气候和地质构造导致大量河口和大片红树林覆盖的沿海平原，部分分隔了由潮汐通道连接的河口盆地。基于对Furo Grande潮汐通道的调查，我们评估了连通性对〜8000 km ²的泥沙输运和演变的相关性。SACZ红树林带。在不同的季节进行了广泛的沉积学和测深调查，以及包括水位，水和沉积物流量以及水的物理化学特征在内的流体力学测量。沿河道的水位变化表明，随着潮汐从两端传播，沉积物-输汇会聚（STC）趋于形成。形态学和沉积学结果表明，STC区内精细沉积物的积累趋势，这与泥浆滞留和进一步输送至红树林平原有关，这最终可能导致通道连接封闭。尽管存在STC，结果还表明，通过研究的河道之间，河口之间存在着重要的悬浮沉积物净通量。然而，Taperaçu和Caeté的相连河口在河流排放，河口过程，潮汐传播和沉积物运输方面存在很大差异。底部沉积物和形态反映了长期趋势，并表明，由于该河口的河水排放量显着较小，因此与Caeté河口相比，STC向Taperaçu迁移，因此沉积物积累速率更高。STC的迁移阻止了连接的关闭，其维护将这些通道保留为河口之间的泥沙流导管。连通性是在该沿海地区重新分配主要是泥质沉积物的关键过程，这有助于解释在SACZ沿岸红树林相对均匀且广泛分布的情况下，其泥浆供应不均。