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Beach nourishment has been widely used for beach protection around the world. However, there is limited information about beach nourishment in China. This study offers an overview of beach nourishment practices, status and technological advances in China, based on the literature, reports, and personal communications. The results demonstrate that beach nourishment has been recognized as an effective and environmentally friendly measure to combat coastal erosion and has been increasingly adopted in China, especially in the past decade. The unique characteristics of coastal China resulted in a difference in beach nourishment between China and Western developed countries in terms of the types, objectives, and shapes of beach nourishment. For the types of nourishments in China, there were approximately the same number of restored beaches and newly constructed beaches. For fill sediment, homogeneous fill and heterogeneous fill comprised 51.1% and 48.9% of projects, respectively. The objective of beach nourishment was mainly to promote coastal tourism, and the shape of nourished beaches was dominated by headland bays. This study also indicated that China has achieved a number of technological advances in beach nourishment, including methods of beach nourishment on severely eroded coasts and muddy coasts, an optimized design of drain pipes involved in urban beaches, and ecological design considerations. From the past decade of practices, four aspects were proposed as considerations for future nourishment: sand sources, technique advances, ecological effects, and management of beach nourishments.

By tracking and monitoring the profile configuration, topography, and hydrodynamic factors of an artificial cobble beach in Tianquan Bay, Xiamen, China over three consecutive years after its completion, we analyzed the evolution of its profile configuration and plane morphology, and its storm response characteristics. The evolution of the profile configuration of the artificial cobble beach in Tianquan Bay can be divided into four stages. The beach was unstable during the initial stage after the beach nourishment the profile configuration changed obviously, and an upper concave composite cobble beach formed gradually, which was characterized by a steep upper part and a gentle lower part. In the second stage, the cobble beach approached dynamic equilibrium with minor changes in the profile configuration. At the third stage the beach was in a high-energy state under the influence of Typhoon Meranti, and the response of the artificial cobble beach differed significantly from that of the low-tide terrace sandy beach. Within a short time, there was net onshore transport of cobbles in the cross-shore direction. The beach face was eroded, the beach berm was accumulated, and the slope of the beach was steepened considerably. In the alongshore direction, there was notable transport of cobbles on the beach from east to west along the shore, and the total volume of the beach decreased by 4.5×103 m3, which accounted for 50% of the total amount of beach volume lost within three years. The fourth stage was the restoration stage after the typhoon, characterized by a little gentler profile slope and the increase in width and the decrease in height of beach berm. Because of the action of waves and the wave-driven longshore current caused by the specific terrain and landform conditions along the coast (e.g., coastal headlands, near-shore artificial structures, and reefs), the coastline of the artificial cobble beach gradually evolved from being essentially parallel to the artificial coast upon completion to a slightly curved parabolic shape, and three distinct erosion hotspots were formed on the west side of the cape and the artificial drainpipe, and the reefs. Generally, the adoption of cobbles for beach nourishment on this macro-tidal coast beach with severe erosion has yielded excellent stability and adaptability.

Beach nourishment is an effective method for maintaining shoreline position, and it has been preferred to restore beaches in China. However, in the post-nourishment assessment, there are only some single-indicator models (e.g. beach durability, sediment loss rate) which could not fully reflect the actual performance of a nourished beach. This study presents a multiple-indicator model of nourished beach stability assessment, aiming at quantitatively assessing the physical performance of nourished beaches. Geomorphic factors affecting the physical performance of nourished beaches were analyzed and summarized through critical review of literature. An indicator system for assessing the stability of nourished beaches was established by integrating oceanographic parameter (i.e. wave energy, storm intensity, and storm frequency), design parameter (i.e. beach length, grain size, volume density, beach planform, and beach protection structure) and adaptability parameter (i.e. intertidal width, dry beach width, and erosional hot spot). Based on data collecting, each indicator was graded into five classes from 1 to 5, and the associated weight of each indicator was given by the method of variation coefficient. Finally, a multi-indicator and indicator-weighted assessment model for the stability of nourished beaches was established and a new index called Nourished Beach Stability Index (NBSI) was proposed. The physical performances of sixteen nourished beaches representative of China were then quantitatively assessed. The results showed this assessment model could better assess the physical performance of nourished beaches than the single-indicator assessment models for taking beach's characteristics into account. The results can help scientists and managers make appropriate management strategies. This multiple-indicator assessment model can be used to both quantitatively assess the actually physical performance of the beach nourishment projects and to choose the design scheme from multiple alternatives for beach nourishment project.

Morphological variations in a sandy-muddy transitional beach (SMT-beach) are expected to coincide with sand-mud transition (SMT) boundary migrations. SMT migrations of SMT-beaches should also differ in river estuaries and semi-enclosed bays due to their contrasting dynamic sedimentary environments. However, the anticipated diversity of SMT migrations of estuarine and bay beaches and their potential morphodynamic responses are still poorly understood. Thus, four measurements of SMT spatial distributions and typical profiles of 6 estuarine beaches and 6 bay beaches located along the macrotidal coasts of the Taiwan Strait, East Asia are presented, and these sites were studied in April and August of 2018 and 2019, respectively. The results show that the SMT boundary of the estuarine beaches continuously migrates landward with increased elevations. Simultaneously, the SMT boundary of bay beaches synchronously remains relatively stable with minor fluctuations and relatively stable elevations. The SMT migration amplitudes present a significantly positive linear correlation with SMT elevation changes, which are strongly controlled by the sediment supply. Following the SMT migration processes, both estuarine and bay beaches display clear erosion during the summer monsoon period that is mainly associated with strong river discharge and monsoon rainfall, respectively. In contrast, all beaches present distinct accretion and recovery during the winter monsoon period that are mainly due to the decreased monsoon rainfall and river discharge and/or the strengthened onshore sediment transport. Despite limitations, the results of this study have clarified the diverse SMT migrations of estuarine and bay beaches and aid in a better understanding of their possible morphodynamic responses.