High-resolution imagery from the WorldView satellite and aerial photos show details that moderate resolution satellite imagery cannot. The result of the land loss and its effect on Isle de Jean Charles becomes clear in these images.
The loss of land in southern Louisiana has several causes.
- Dams Upriver, dams trap sediment that normally flowed to the delta and built it up.
- Subsidence The land in the Louisiana delta has always sunk naturally. Faults contribute to regional subsidence, and sediments naturally compress over time. Deposits flowing from the Mississippi River continually replenished and built up the land. Much of this sediment is now trapped by upstream dams, taking away the rebuilding process.
- Sea level rise The long-term gradual rise in sea level combined with that subsidence increases the land loss more than either factor alone.
- Canals 10,000 miles of canals dug through the marshland, built for oil and gas production activities, bring saltwater farther inland, which degrades freshwater marshlands.
- Hurricanes Storm surge and waves can propagate farther inland because of land loss, making matters worse. Hurricanes erode the soft land from the coast and can damage both vulnerable and healthy marshlands.
The saltwater that washes farther inland also invades the soil and has made the area no longer good for farming. As the marshland retreats, the saltwater enters bald cypress swamp and kills the trees.
The only road into or out of the island is the 2-mile-long Island Road. When it was built in 1953, land and marsh surrounded it. Tribal members hunted and trapped on the land around the road. It now cuts across open water. It often submerges during high tide, and erosion continues to eat away at the roadbed.