Remote sensing for wetland mapping and historical change detection at the Nisqually River Delta

Sustainability
By: , and 

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Abstract

Coastal wetlands are important ecosystems for carbon storage and coastal resilience to climate change and sea-level rise. As such, changes in wetland habitat types can also impact ecosystem functions. Our goal was to quantify historical vegetation change within the Nisqually River watershed relevant to carbon storage, wildlife habitat, and wetland sustainability, and identify watershed-scale anthropogenic and hydrodynamic drivers of these changes. To achieve this, we produced time-series classifications of habitat, photosynthetic pathway functional types and species in the Nisqually River Delta for the years 1957, 1980, and 2015. Using an object-oriented approach, we performed a hierarchical classification on historical and current imagery to identify change within the watershed and wetland ecosystems. We found a 188.4 ha (79%) increase in emergent marsh wetland within the Nisqually River Delta between 1957 and 2015 as a result of restoration efforts that occurred in several phases through 2009. Despite these wetland gains, a total of 83.1 ha (35%) of marsh was lost between 1957 and 2015, particularly in areas near the Nisqually River mouth due to erosion and shifting river channels, resulting in a net wetland gain of 105.4 ha (44%). We found the trajectory of wetland recovery coincided with previous studies, demonstrating the role of remote sensing for historical wetland change detection as well as future coastal wetland monitoring.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Remote sensing for wetland mapping and historical change detection at the Nisqually River Delta
Series title Sustainability
DOI 10.3390/su9111919
Volume 9
Issue 11
Year Published 2017
Language English
Publisher MDPI
Contributing office(s) Western Geographic Science Center
Description Article 1919; 32 p.
First page 1
Last page 32
Country United States
State Washington
Other Geospatial Nisqually River Delta