Land Use and Land Cover Regional Summary

The land use and land cover indicator is determined using high resolution change detection. The Puget Sound Salmon Recovery Region targeted Water Resource Inventory Area (WRIA) 3, which covers about 4.26 percent of the region, for analysis. In 2009-2011,  WRIA 3 had the second most development-related change (297 acres) of the eight WRIAs mapped following only WRIA 15, which is part of both the Hood Canal and Puget Sound Salmon Recovery Regions. The urban growth areas (at 37,188 acres) comprise about 10 percent of the land area but hosted 33 percent of change mapped as development. The rate of change due to development was about 4.4 times higher in the urban growth areas than outside it (0.26 percent inside the urban growth areas compared to 0.06 percent outside).

WRIA 3 2011 NAIP image over LANDSAT background

In the image above, change locations are mapped in red.

The pie charts show the distribution of types of changes in and outside the urban growth areas. In WRIA 3, almost all (97 percent) of change (3,866 of the 3,994 acres) took place outside the urban growth areas, and most of that (93 percent) was logging or an indeterminate use. Of the 128 acres of change inside the urban growth areas, 76 percent was development-related.

This is a view of Sedro-Wooley. The black hatched area is within the city and urban growth areas of WRIA 3. The dark blue lines show mapped fish-bearing streams. The light blue lines are 25-meter buffers around the streams extending out to 200 meters. The red-outlined areas are mapped as change between 2009 and 2011. Using these data, the relative change rates for areas inside and outside the cities and their urban growth areas and near streams, can be calculated. The change rates around streams assume the stream locations are correct and does not take into account stream width.









Change within 25m bands of fish bearing streams within the CityUGAs
Buffer (m) Development (ac) Forestry (ac) Development (%) Forestry (%) UGA Buffer (ac)
25 1.91 0.01 0.12 0.00 1628.00
50 3.27 1.45 0.10 0.04 3294.00
75 5.46 3.96 0.11 0.08 4989.00
100 7.80 6.70 0.12 0.10 6705.00
125 12.37 9.79 0.15 0.12 8438.00
150 17.34 12.98 0.17 0.13 10191.00
175 22.66 16.28 0.19 0.14 11963.00
200 27.99 19.71 0.20 0.14 13746.00

The table shows the amount of change within different buffer distances in the UGAs. For example the last line shows that 27.99 acres of development occurred within 200m of fish bearing streams wirthin the UGAs. The total area of that buffer was 13,746 acres so the change rate was 0.2% for the 2009-2011 period.










Change within 25m bands of fish bearing streams for the entire WRIA
Buffer (m) Development (ac) Forestry (ac) Natural (ac) Development (%) Forestry (%) Natural (%) Buffer (ac)
25 5.42 5.51 1.27 0.05 0.05 0.01 11106.00
50 10.91 16.96 2.00 0.05 0.08 0.01 22263.00
75 18.25 51.42 2.57 0.06 0.15 0.01 33410.00
100 28.88 109.58 2.97 0.06 0.25 0.01 44532.00
125 43.90 183.74 3.44 0.08 0.33 0.01 55609.00
150 60.57 264.01 4.06 0.09 0.40 0.01 66600.00
175 77.78 350.66 4.42 0.10 0.45 0.01 77519.00
200 95.84 441.27 4.66 0.11 0.50 0.00 88358.00

The table shows the amount of change within different buffer distances for the entire WRIA. For example the last line shows that 441 acres of forestry/indeterminate occurred within 200m of fish bearing streams. The total area of that buffer was 88,358 acres so the change rate was 0.5% for the 2009-2011 period.

Region

Puget Sound

WRIA area

370,547 acres

UGA area

37,188 acres

Length of fish stream

832 km

Mapped change area

3,994 acres

Development related change

297 acres

Naturally occuring change

69 acres

WRIA 3 NLCD 2006

Snow & Ice 0.0%
Urban/Suburban 12.0%
Barren 4.4%
Forest 44.5%
Scrub 6.7%
Grasslands 2.7%
Agriculture 19.4%
Woody and Herbaceous
Wetlands
10.3%

DATA SOURCE: WASHINGTON DEPARTMENT OF FISH AND WILDLIFE