海滩养护工程影响下的风沙增长效应研究

海滩养护已成为海岸生态修复的主要工程手段，其在抵御海岸侵蚀的同时产生了海岸风沙作用增强等环境效应，并表现出异于自然海滩风沙作用的特征，形成人类活动影响下的海岸风沙运动新形式。前人对养护海滩引起的风沙要素变化和搬运过程的研究较少，本项目聚焦养护海滩的风沙增长效应问题，采用风况测量、风沙运动观测、滩面沉积物变化调查等野外实验与风场数值模拟相结合的研究手段，紧扣海滩养护前后滩面形态和高程、海滩沉积物粒径与组分特征等主要控制性因素变化，通过对滩面风场、风区长度、沉积物组分、起动风速、输沙率和风沙通量等方面的变化分析，探讨养护海滩引起的形态和沉积物的变化对风沙作用的影响，建立养护海滩风沙增长指数，定量评估养护工程的海滩风沙效应。研究成果将为海滩养护工程的风沙防护和养护海滩形态设计提供科学支撑。

Beach nourishment has become the main engineering method of coastal ecological restoration, despite of the function of decreasing coastal erosion, it also has other environmental effects especially enhancing the beach aeolian sand transport. Different from natural beach, nourished beach shows a new form of coastal aeolian sand transport under the influence of human activities. In view of the weakness of previous research on the effect of aeolian sand transport of nourished beach, this study focuses on the growth of aeolian sand transport influenced by beach nourishment. Wind condition measurement, aeolian sand transport observation, sediment composition investigation and analysis, and wind field numerical simulation will be carried out in this project. The change of main control factors such as morphology and elevation of the nourished beach, the grain size and composition characteristics of sediment are considered and observed. Based on the multi-factor analysis of beachface wind field, fetch length, sediment composition, entrainment speed, transport rate and sand flux, the impact of the change in the morphology and sediment characteristics of nourished beach on aeolian sand transport will be discussed. The aeolian sand flux growth index is finally established to quantitatively evaluate the growth effect of aeolian sand transport of nourishment project. The research result will provide scientific support for the aeolian sand prevention and the morphology design of beach nourishment project.