Abstract. Chronic flooding, occurring at high tides under calm weather conditions, is occasionally taking place today in the low-lying areas of the Petit-Cul-de-sac marin (Guadeloupe, West Indies, French Antilles). This area includes critical industrial, harbor and major economic infrastructures for the island. As sea level rises, concerns are growing regarding the possibility for repeated chronic flooding events, which would alter the operations at these critical coastal infrastructures without appropriate adaptation. Here, we use information on past and future sea levels, vertical ground motion and tides to assess times of emergence of chronic flooding in the Petit-Cul-de-sac marin. For RCP8.5 (i.e., continued growth of greenhouse gas emissions), the number of flood days is projected to increase rapidly after the emergence of the process, so that coastal sites will be flooded every two days within 2 decades after the onset of chronic flooding. For coastal locations with the smallest altitude, we show that the reconstructed number of floods are consistent with observations known from a previous survey. One key uncertainty of our result is the actual rate of subsidence of the island. However, our satellite interferometric synthetic-aperture radar results show that the local variability of this subsidence is smaller than the uncertainties of the technique, which we estimate between 1 (standard deviation of measurements) and 5 mm/yr (upper theoretical bound). Our results imply that adaptation pathways considering a rapid increase of recurrent chronic flooding are required in the critical port, industrial and commercial center of Guadeloupe, as well as presumably in many low-elevation coastal zones of other tropical islands.

中文翻译：

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瓜德罗普岛主要经济中心发生的慢性妨害洪水的时间表

摘要。今天，在平静的天气条件下，高潮时发生的长期洪水有时在Petit-Cul-de-sac marin（瓜德罗普岛，西印度群岛，法属安的列斯群岛）的低洼地区发生。该地区包括该岛的关键工业，港口和主要经济基础设施。随着海平面上升，人们对于不断发生的长期洪灾事件的担忧日益增加，这可能会在没有适当适应的情况下改变这些关键沿海基础设施的作业。在这里，我们使用有关过去和将来的海平面，垂直地面运动和潮汐的信息来评估Petit-Cul-de-sac marin中长期洪水泛滥的时间。对于RCP8.5（即温室气体排放量的持续增长），预计洪水天数在该过程出现后将迅速增加，因此，在慢性洪灾发生后的20年内，每两天将淹没沿海一带。对于海拔最小的沿海地区，我们表明洪水的重建数量与先前调查中发现的观测结果一致。我们结果的关键不确定因素之一是该岛的实际沉降速度。但是，我们的卫星干涉合成孔径雷达结果表明，该沉降的局部变化小于该技术的不确定性，该技术的不确定性在1（测量的标准偏差）至5 mm / yr（理论上限）之间。我们的结果表明，在瓜德罗普岛的关键港口，工商业中心，需要考虑到经常性慢性洪水迅速增加的适应途径，