Our Work » Historical Change

Analysis of Historical Change

To begin to understand the  problems the Puget Sound nearshore is facing today, it is necessary identify where and how the nearshore has changed over time.  Identification of changes to nearshore structure serves as a proxy for our understanding of historical nearshore process since we don’t have historical records specific to nearshore processes.

Categories of Change

Using process units as the area of study, historical change was analyzed for 4 categories (tiers),

Tier 1
Shoreform (Landform) Change
Tier One
Changes from one shore form type to another
Tier 2
Shoreline Modifications
Tier Two

Changes in wetlands and man-made features (stressors) along the shoreline

(e.g. bulkheads, marinas, railroads, wharves/piers/docks)

Tier 3
Nearshore Zone Modifications
Tier Three

Man-made changes within 200 meters of the shoreline

(e.g. roads, impervious surface, land cover)

Tier 4
Drainage Area Modification
Tier Four

Man-made changes in the entire drainage area

(e.g. roads, impervious surface, land cover)

 

Shoreform Composition Change in Puget Sound (Tier 1)

Sample results from the change analysis.

Example of Change Analysis
The Puget Sound shoreline has gotten shorter and there is more artificial shoreline than in historical conditions

 

Data Availability

The geodatabase and geospatial methodology are available on the WAGDA website.

To evaluate change, PSNERP used data between the earliest land surveys of the General Land Office and U.S. Coast and Geodetic Survey (1850s–1890s) and present conditions (2000–2006).  Data used for this analysis was:

1) related directly to nearshore ecosystem processes
2) spatially explicit
3) comprehensive, complete and of uniform resolution and quality Sound-wide
4) well documented
5) in, or readily convertible, to GIS format

Historical?

We view historical condition as an important baseline or reference point for restoration and preservation, but caution that historical condition should not be made a restoration/preservation target without considering modern constraints.


Historical Change and Impairment of Puget Sound Shorelines

Historical Change and Impairment of Puget Sound Shorelines

(PDF, 30 MB)


How to View Change Analysis Results
for Your Area

The Project Map has a feature that allows users to select an area of interest and view summary data.

gif Zoom to area of interest
gif Click on shoreline of interest
gif Click on blue link in pop-up box
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Puget Sound Nearshore Ecosystem Restoration Project
Updated July 2016