Coastal zones have large social, economic and environmental values. They are more densely populated than the hinterland and concentrate large economic assets, critical infrastructures and human activities such as tourism, fisheries, navigation. Furthermore, coastal oceans are home to a wealth of living marine resources and very productive ecosystems. Yet, coastal zones are exposed to various natural and anthropogenic hazards. To reduce the risks associated with marine hazards, sustained coastal zone monitoring programs, forecasting and early warning systems are increasingly needed. Earth observations (EO), and in particular satellite remote sensing, provide invaluable information: satellite-borne sensors allow an effective monitoring of the quasi-global ocean, with synoptic views of large areas, good spatial and temporal resolution, and sustained time-series covering several years to decades. However, satellite observations do not always meet the precision required by users, in particular in dynamic coastal zones, characterized by shorter-scale variability. A variety of sensors are used to directly monitor the coastal zone and their observations can also be integrated into numerical models to provide a full 4D monitoring of the ocean and forecasts. Here, we review how EO, and more particularly satellite observations, can monitor coastal hazards and their drivers. These include coastal flooding, shoreline changes, maritime security, marine pollution, water quality, and marine ecology shifts on the one hand, and several physical characteristics (bathymetry, topography, vertical land motion) of coastal zones, meteorological and oceanic (metocean) variables that can act as forcing factors for coastal hazards on the other hand.

中文翻译：

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监测海洋沿海灾害及其驱动因素的地球观测

沿海地区具有巨大的社会、经济和环境价值。它们比腹地人口更稠密，集中了大量经济资产、关键基础设施和人类活动，如旅游、渔业、航海。此外，沿海海洋拥有丰富的海洋生物资源和高产的生态系统。然而，沿海地区面临着各种自然和人为灾害。为了减少与海洋灾害相关的风险，越来越需要持续的沿海地区监测计划、预测和预警系统。地球观测（EO），尤其是卫星遥感，提供了宝贵的信息：星载传感器可以有效监测准全球海洋，具有大面积的天气视图，良好的空间和时间分辨率，和持续的时间序列，涵盖几年到几十年。然而，卫星观测并不总能满足用户要求的精度，特别是在动态沿海地区，其特点是尺度较短。各种传感器用于直接监测沿海地区，它们的观测也可以集成到数值模型中，以提供对海洋的完整 4D 监测和预测。在这里，我们回顾了 EO，尤其是卫星观测，如何监测沿海灾害及其驱动因素。这些一方面包括沿海洪水、海岸线变化、海上安全、海洋污染、水质和海洋生态变化，以及沿海地区的几个物理特征（测深、地形、垂直陆地运动），