A study published in Earth’s Future is based on the measurements of NASA’s ICESat-2 lidar satellite system instead of radar. The area exposed to flooding increases more in the early stages of water rise than in subsequent phases
New satellite surveys update estimates on the impact of Increase in sea levels on coastal areas
We will feel the impact of an increase in sea levels much earlier than expected. Many coastal areas, in fact, are situated at an average height lower than that estimated so far. For them, the risk of flooding is more real. And they will end up underwater decades before what is estimated today.
This is the conclusion reached by a study published in Earth’s Future that revises the data on the elevation of coastal areas based on the measurements of the NASA ICESat-2 lidar satellite system. Previously, estimates of the impact of Increase in sea levels were made from radar data.
New estimates on Increase in sea level
The problem? The trees and the bushes. “The radar is not able to completely penetrate the vegetation and therefore overestimates the height of the surface,” explains Ronald Vernimmen, a researcher at the Dutch research company Data for Sustainability and the first signature of the work. Using satellite data, a different photograph emerges. Which requires coastal communities to accelerate preparations to adapt to the arrival of water.
“The radar-based land elevation models applied so far suggest that the increase in the area below average sea level, potentially exposed to permanent flooding, will accelerate as Increase in sea level, being initially relatively limited“, reads the study. “However, by applying the new and more accurate lidar elevation data, we found an opposite pattern, with the faster increase in the exposed area occurring in the early stages of rising sea levels”.
This is not the first time that reanalysis with satellite data has worsened estimates in this area. In a third of the countries analyzed in this study, most of this increase in the flood area will occur while the first meter of water rise accumulates. And in almost all countries this will happen within the first 2 meters. For comparison, by 2100 the IPCC estimates that the increase in global oceans could be between 60 cm and 1,1 m.
