A research paper finds that delta cities are at risk subsidence and sea level rise.From The Conversation, Delta cities, wealthy or not, face rising risk from sinking land
Coastal deltas are becoming more at risk of flooding due to land subsidence, or the gradual sinking of the Earth’s surface, and sea-level rise.
Conventional protective infrastructure, such as levees, may reduce current risk but it doesn’t address underlying causes of subsidence, potentially leading to far greater challenges in the future.
The world’s deltas are home to over 340 million people, a population greater than that of the United States. These delta communities are highly at risk from flooding, and future sea-level rise will make these risks worse. Sea-level rise associated with climate change is rightly considered a major threat to all coastal communities around the world, but deltas face additional challenges due to their unique geological characteristics.
River deltas are formed by deposition of sediments over time. If, as in most coastal cities, the river is constrained, the delta formation is constrained. If you also withdraw water, it adds to subsidence. The article starts with a photo of New Orleans (I10) flooding during Katrina. New Orleans is mostly below sea level, protected from the Mississippi River by levee’s (the Mississippi River & Tributary levee system is 3,500 miles). Have a breach and pump failure in New Orleans and flooding is very possible.
Sea levels have been rising and people build and live on deltas and interfere with the natural process. So, isn’t it intuitively obvious that infrastructure will be at risk to keep up?