February 26, 2024

NASA Satellites Help Scientists Track Staggering Wetlands Loss in Louisiana

Reinforced levees and thousands of miles of canals and excavated banks have separated numerous wetlands from the Mississippi River and the network of streams that course through its delta-like veins and blood vessels. The researchers said their approach could be used beyond Louisiana due to the fact that wetland loss and resiliency is a worldwide phenomenon. From the Great Lakes to the Nile Delta, the Amazon to Siberia, wetlands are discovered on every continent except Antarctica. Wetlands were just recently called some of the “most vulnerable, the majority of threatened, most important, and the majority of varied” communities on the world, according to a global analysis co-authored by NASA researchers.
At current rates of wetland loss in coastal Louisiana, carbon burial may have decreased 50% from 2013 estimates.

Centimeter by centimeter, wetlands are developed by the slow accumulation– accretion– of mineral sediment and natural material carried by streams and rivers. Accretion makes new soil and counters erosion, the sinking of land, and the increase of sea level.
The scientists mapped land change in seaside Louisiana from 1984 to 2020. Basins that stopped working to develop brand-new soil, such as Terrebonne and Barataria, experienced the a lot of land loss– more than 180 square miles (466 square kilometers). Credit: Jensen et al. Journal of Geophysical Research: Biogeosciences
Human intervention and engineering often keep back or divert the flow of sediments that naturally accrete to construct and renew wetlands. For instance, enhanced levees and countless miles of canals and excavated banks have isolated lots of wetlands from the Mississippi River and the network of streams that course through its delta-like veins and blood vessels. In a few cases, engineering tasks have actually added sediment to delta areas and developed colony.
By analyzing Landsat imagery with tools from cloud computing, the researchers established a remote noticing model that concentrated on accretion or the absence of it. Basins that stopped working to construct new soil, such as Terrebonne and Barataria, experienced one of the most land loss over the study period– more than 180 square miles (466 square kilometers). Other locations picked up speed, consisting of 33.6 square miles (87 square kilometers) of colony in the Atchafalaya Basin and 43 square miles (112 square kilometers) in the area referred to as the “Birds Foot Delta” at the mouth of the Mississippi River.
” The Louisiana seaside system is highly crafted,” stated Daniel Jensen, lead author and postdoctoral scientist at NASAs Jet Propulsion Laboratory in Southern California. “But the fact that ground has actually been gained in some places suggests that, with enough restoration efforts to reintroduce fresh supply of water and sediment, we could see some wetland healing in the future.”
A map of soil accretion in seaside Louisiana showing higher accumulation in parts of Atchafalaya and the “Birds Foot Delta,” where the Mississippi River system deposits mineral-rich sediment throughout flood periods.Credit: Jensen et al. Journal of Geophysical Research: Biogeosciences
Understanding wetland dieback and recovery is critically crucial due to the fact that the Mississippi River Delta, like many of the worlds deltas, drives regional and nationwide economies through farming, fisheries, tourism, and shipping. “For the 350 million individuals who live and farm on deltas around the world, seaside wetlands supply an essential link in the food chain,” said JPLs Marc Simard, principal investigator of NASAs Delta-X mission and co-author of the paper.
In a number of air-borne and field projects since 2016, the Delta-X research study group has been studying the Mississippi River Delta, the seventh largest on Earth, using airborne noticing and field measurements of sediment, water, and vegetation modifications in the face of increasing water level. The Landsat analysis constructs on this airborne mission. Delta-X becomes part of NASAs Earth Venture Suborbital (EVS) program, managed at NASAs Langley Research Center in Hampton, Virginia.
The new model by Jensen and associates is the first to straight estimate soil accretion rates in coastal wetlands utilizing satellite information. Dealing with ground-based accretion records from Louisianas Coastwide Reference Monitoring System, the researchers had the ability to approximate quantities of mineral sediment from water pixels in the Landsat images and organic product from the land pixels.
The researchers said their approach might be used beyond Louisiana because wetland loss and resiliency is a worldwide phenomenon. From the Great Lakes to the Nile Delta, the Amazon to Siberia, wetlands are found on every continent other than Antarctica.
But they likewise said a new generation of spaceborne tools, such as artificial aperture radar, can progressively inform conservation policies on the ground. This is due to the fact that satellites support near-continuous mapping of communities at a scale and consistency that is almost difficult through traditional studies and fieldwork.
The futures of our wetlands and coastal communities are linked with climate change, so sustainable management is important. By storing decomposing plant matter in soil and roots, wetlands act as “blue carbon” sinks, preventing some greenhouse gases (carbon dioxide and methane) from escaping into the environment. When vegetation passes away, drowns, and stops working to grow back, wetlands can no longer sequester (bury) carbon in soil and plants. At existing rates of wetland loss in seaside Louisiana, carbon burial may have decreased 50% from 2013 estimates.
” Forty percent of the human population lives within a hundred kilometers of a coast,” Simard stated. “Its vital that we understand the procedures that secure those lands and the income of individuals living there.”
Recommendation: “Leveraging the Historical Landsat Catalog for a Remote Sensing Model of Wetland Accretion in Coastal Louisiana” by D. J. Jensen, K. C. Cavanaugh, D. R. Thompson, S. Fagherazzi, L. Cortese and M. Simard, 1 June 2022, JGR Biogeosciences.DOI: 10.1029/ 2022JG006794.

A satellite image of the Mississippi River Delta with land displayed in brilliant green and water displayed in dark blue. Credit: NASA Earth Observatory image by Michael Taylor and Adam Voiland, utilizing Landsat information from the U.S. Geological Survey
New research study utilizes NASA satellite observations and advanced calculating to chronicle wetlands lost (and found) around the globe.
From Lake Pontchartrain to the Texas border, Louisiana has lost enough wetlands considering that the mid-1950s to cover the entire state of Rhode Island. Utilizing a first-of-its-kind design, NASA-funded researchers quantified those wetlands losses at almost 21 square miles (54 square kilometers) each year since the early 1980s.
In the brand-new research study, scientists utilized the NASA/USGS Landsat satellite record to track shoreline modifications across Louisiana from 1984 to 2020. A few of those wetlands were immersed by rising seas; others were interfered with by oil and gas facilities and cyclones. The primary driver of losses was coastal and river engineering, which can have positive or negative effects depending on how it is implemented.