Sea Level Rise and the Observation of Change in Mudflat Geomorphology and Land Cover

Project Lead

Ildiko C. Pechmann

Problem

Significant changes in the external forcing on the Meadowlands' marshes have occurred in the past decades. Records show a ~20 cm increase in sea level since 1970 and a much faster rate of 8 mm per year from now to 2030. Similarly, the sediment supply has been modified by land development. During the past decade, sediment accretion rates of 6 mm/year and more have contributed to changes in the elevation of the marsh plain compared to a decade ago. Sea level rise also influences wetland retreat as mudflats and marsh surfaces are mutually adjusting to increased inundation periods and changes in sediment supply.

Objectives

Measure indicators of marsh resilience to identify marshes in the District that have the most chance of persistence under future sea-level rise (SLR) conditions.

Strategy

Acquire data from tidal datum, LiDAR, drone, and hyperspectral imagery, and integrate these with existing sediment accretion rates and marsh elevation point measurements. Arrive at mapped stability metrics and show marshes with the most chance of persisting under future sea-level rise conditions.

Activities

Acquire LiDAR and Hyperspectral Imagery of the Meadowlands
Acquire drone images and Tidal Datum of selected shorelines.
Compare 2009 and 2014 LiDAR data to 2022 using the respective DEMs
Assess changes in plant cover and plant health by comparing the 2009, 2014, and 2022 hyperspectral imagery
Assess shoreline retraction or expansion using drone imagery and LiDAR data