Abstract

The African continent hosts some of the largest freshwater systems worldwide, characterized by a large distribution and variability of surface waters that play a key role in the water, energy and carbon cycles and are of major importance to the global climate and water resources. Freshwater availability in Africa has now become of major concern under the combined effect of climate change, environmental alterations and anthropogenic pressure. However, the hydrology of the African river basins remains one of the least studied worldwide and a better monitoring and understanding of the hydrological processes across the continent become fundamental. Earth Observation, that offers a cost-effective means for monitoring the terrestrial water cycle, plays a major role in supporting surface hydrology investigations. Remote sensing advances are therefore a game changer to develop comprehensive observing systems to monitor Africa’s land water and manage its water resources. Here, we review the achievements of more than three decades of advances using remote sensing to study surface waters in Africa, highlighting the current benefits and difficulties. We show how the availability of a large number of sensors and observations, coupled with models, offers new possibilities to monitor a continent with scarce gauged stations. In the context of upcoming satellite missions dedicated to surface hydrology, such as the Surface Water and Ocean Topography (SWOT), we discuss future opportunities and how the use of remote sensing could benefit scientific and societal applications, such as water resource management, flood risk prevention and environment monitoring under current global change.

Article Highlights

• The hydrology of African surface water is of global importance, yet it remains poorly monitored and understood

• Comprehensive review of remote sensing and modeling advances to monitor Africa’s surface water and water resources

• Future opportunities with upcoming satellite missions and to translate scientific advances into societal applications

中文翻译：

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全球变化下非洲的水资源：从太空监测地表水

摘要

非洲大陆拥有世界上一些最大的淡水系统，其特点是地表水分布广泛且多变，在水、能源和碳循环中发挥着关键作用，对全球气候和水资源具有重要意义。在气候变化、环境改变和人为压力的综合影响下，非洲的淡水供应现已成为一个主要问题。然而，非洲河流域的水文学仍然是世界上研究最少的地区之一，更好地监测和了解整个大陆的水文过程变得至关重要。地球观测提供了一种具有成本效益的监测陆地水循环的方法，在支持地表水文调查方面发挥着重要作用。因此，遥感技术的进步改变了游戏规则，可以开发综合观测系统来监测非洲的陆地水并管理其水资源。在这里，我们回顾了三十多年来利用遥感技术研究非洲地表水所取得的进展，强调了当前的好处和困难。我们展示了大量传感器和观测的可用性，再加上模型，如何为监测一个缺乏测量站的大陆提供新的可能性。在即将开展的地表水文卫星任务（例如地表水和海洋地形 (SWOT)）的背景下，我们讨论了未来的机遇以及遥感的使用如何有益于科学和社会应用，例如水资源管理、

文章亮点

• 非洲地表水的水文学具有全球重要性，但仍缺乏监测和了解

• 全面审查遥感和建模进展以监测非洲地表水和水资源

• 即将到来的卫星任务以及将科学进步转化为社会应用的未来机会