2024-12-11 NASA
＜関連情報＞
- https://www.nasa.gov/missions/space-shuttle/srtm/nasa-dod-study-saltwater-to-widely-taint-coastal-groundwater-by-2100/
- https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL110359
2100年の気候による塩水流入： 涵養がもたらす深刻さと海面がもたらす多発性 Climate-Induced Saltwater Intrusion in 2100: Recharge-Driven Severity, Sea Level-Driven Prevalence
Kyra H. Adams, J. T. Reager, Brett A. Buzzanga, Cédric H. David, Audrey H. Sawyer, Benjamin D. Hamlington
Geophysical Research Letters Published: 22 November 2024
DOI:https://doi.org/10.1029/2024GL110359
Abstract
Saltwater intrusion is a critical concern for coastal communities due to its impacts on fresh ecosystems and civil infrastructure. Declining recharge and rising sea level are the two dominant drivers of saltwater intrusion along the land-ocean continuum, but there are currently no global estimates of future saltwater intrusion that synthesize these two spatially variable processes. Here, for the first time, we provide a novel assessment of global saltwater intrusion risk by integrating future recharge and sea level rise while considering the unique geology and topography of coastal regions. We show that nearly 77% of global coastal areas below 60° north will undergo saltwater intrusion by 2100, with different dominant drivers. Climate-driven changes in subsurface water replenishment (recharge) is responsible for the high-magnitude cases of saltwater intrusion, whereas sea level rise and coastline migration are responsible for the global pervasiveness of saltwater intrusion and have a greater effect on low-lying areas.
Key Points
- First global analysis of future saltwater intrusion vulnerability responding to spatially variable recharge and sea level rise is provided
- Recharge drives the extreme cases of saltwater intrusion, while sea level rise is responsible for its global pervasiveness
- Nearly 77% of global coastal areas below 60° north will undergo saltwater intrusion by 2100
Plain Language Summary
Coastal watersheds around the globe are facing perilous changes to their freshwater systems. Driven by climatic changes in recharge and sea level working in tandem, sea water encroaches into coastal groundwater aquifers and consequently salinizes fresh groundwater, in a process called saltwater intrusion. To assess the vulnerability of coastal watersheds to future saltwater intrusion, we applied projections of sea level and groundwater recharge to a global analytical modeling framework. Nearly 77% of the global coast is expected to undergo measurable salinization by the year 2100. Changes in recharge have a greater effect on the magnitude of salinization, whereas sea level rise drives the widespread extensiveness of salinization around the global coast. Our results highlight the variable pressures of climate change on coastal regions and have implications for prioritizing management solutions.
