Details of Washington Statewide Master Sample

Contact Info

Jenelle Black, Forest Hydrologist
CMER Technical Project Manager
Northwest Indian Fisheries Commission
6730 Martin Way E. Olympia, WA 98516
425-445-7034 (cell), 509-649-2538 (home office)
360-528-4376, 360-438-1180 x376 jblack@nwifc.org

Anthony (Tony) R. Olsen
USEPA NHEERL
Western Ecology Division
200 S.W. 35th Street
Corvallis, OR 97333
Voice: (541) 754-4790
Fax: (541) 754-4716
email: olsen.tony@epa.gov

Origin

http://www.ecy.wa.gov/services/gis/data/enviro/mastersample.htm

Target Population

All streams and rivers identified by the DNR WRIA and County GIS shapefiles.

Sample Frame

To identify the target population streams, DNR WRIA and County GIS shapefiles were used. They were obtained from web sites: Data for western Washington was downloaded by county from To identify the target population streams, DNR WRIA and County GIS shapefiles were used. They were obtained from web sites: Data for western Washington was downloaded by county from http://fortress.wa.gov/dnr/app1/dataweb/dmmatrix.html. Data for eastern Washington was downloaded by WRIA from ftp://198.187.3.44/fp/watertyping/. They were downloaded on February 22, 2005 and represent the stream network at that point in time. Note that the sample frame has streams mapped at different densities across the state. Densities are greater in "sections" of interest to DNR. Below are comments from Jennelle concerning the alternative hydrology layers available for potential use:

"Here are clarifications on some of the hydrography data issues and questions we raised at our meeting last week.

Regarding differences in stream scale/resolution among differing land ownerships across the state in the DNR hydrography layers: There are none. Stream linework is at 1:24,000 for ALL ownerships.

Regarding what stream linework each of several existing hydrography layers contains and is based on:

Most relevantly, the "new" DNR Hydro layer linework is based on refinement of the "old" DNR Hydro layer, not on newly-modeled linework as I had thought. I misunderstood before; the DEM was used in modeling the locations of the F/N type breaks, but those breakpoints were then transfered to the old linework. The base linework was originally developed from 7.5 minute USGS topo quads (1:24,000) for the entire state. In the early 90s, the DNR undertook to validate and refine the linework using aerial photos for all state and private lands, by township. For all townships that had ANY amount of state/private land, even a few acres, the entire township was assessed and the linework appropriately modified (including densified). This stream network has been (still in process in Eastern Washington) further upgraded to conform with ground truthing submitted on change forms over the years. (NOTE TO DNR: what about changes noted in watershed analyses) There are GIS attributes associated with the line segments that note their source and level of verification.

I learned of another stream layer under development in addition to the new NHD layer. FRAMEWORK is the other layer that has been developed in conjunction with the USFS, BLM and some Washington and Oregon state agencies. The Framework layer was completed 2-3 weeks ago and is based largely on the DNR Hydro layer linework but has been clipped and appended at Federal land boundaries to use those agencies' working linework. The Federal agency working linework data were also developed from 7.5 minute topos but for the most part were never photogrammetrically verified and are less dense than the DNR version. The Framework layer does not currently incorporate any Washington State stream type information and is not readily-ammenable to doing so, although there is ongoing discussion of incorporating stream types at some point in time. This layer also does not contain the last four years of DNR stream channel updates.

As we discussed on Friday, the new National Hydrographic Data (NHD) layer is also to be based on the DNR hydro layer. However, like FRAMEWORK, it has much information stripped out of it, including many the lower-order streams that we are interested in and the stream type information. It will effectively be a subset of the FRAMEWORK layer, which is in turn a subset of the DNR Hydro layer. The development status of the NHD layer is not clear to me at this time; one report is that it is completed and another is that it has yet to be begun.

My overall conclusion is that the DNR Hydrography layer is the layer to use for the statewide master sample draw. It has the most detailed, has the most up-todate information (most submitted channel changes have been imported), has the stream type information we at CMER rely on for our studies, and is the basis for the other two primary stream channel layers that have been recently proposed for statewide monitoring. I believe it should be used for the master site draw since will be possible to select a subset of sample points that are on the other two less detailed layers whereas the opposite is not true."

Survey Design

A Generalized Random Tessellation Stratified (GRTS) survey design for a linear resource was used. The GRTS design includes reverse hierarchical ordering of the selected sites. In order to select the sample, each WRIA and county initially was used to select a master sample for that geographic unit. The sites selected were then combined into a single point shapefile for the entire state. The GRTS reverse hierarchical ordering was applied to the entire set of points (i.e., all sites were included). To overcome computational limitations, this was done by selecting GRTS samples of size 20,000 without replacement until all sites were selected. The resulting design is a spatially-balanced sample with sites in reverse hierarchical order (siteID) across the state.

Multi Density Categories

<none>

Stratification

<none>

Panels

<none>

Expected Sample Size

Expected sample size is one site per km of stream length in the sample frame.

Over Sample

<none>

Site Use

Sites are listed in SiteID order and must be used in that order. All sites that occur prior to the last site used must have been evaluated for use and then either sampled or reason documented why that site was not used.

Year Created

2006

Sample Frame Summary

Total stream length (in km) is 387,235.6. Stream length (km) by WRIA or County is given below.

clallum = 12098
clark = 3901
cowlitz = 13211
grays harbor = 17420
island = 359
jefferson = 11775
king = 13750
kitsap = 1614
lewis = 24765
mason = 5028
pacific = 14908
pierce = 8228
sanjuan = 365
skagit = 10188
skamania = 11019
snohomish = 12024
thurston = 4316
wahkeakum = 3976
whatcom = 9122
WRIA29 = 2913
WRIA30 = 6030
WRIA31 = 5832
WRIA32 = 6336
WRIA33 = 2088
WRIA34 = 9780
WRIA35 = 11613
WRIA36 = 5185
WRIA37 = 13789
WRIA38 = 4723
WRIA39 = 14380
WRIA40 = 2877
WRIA41 = 7453
WRIA42 = 1888
WRIA43 = 5122
WRIA44 = 3628
WRIA45 = 15650
WRIA46 = 4935
WRIA47 = 6117
WRIA48 = 10760
WRIA49 = 12879
WRIA50 = 2704
WRIA51 = 1695
WRIA52 = 7107
WRIA53 = 3247
WRIA54 = 4465
WRIA55 = 3594
WRIA56 = 1736
WRIA57 = 1804
WRIA58 = 7117
WRIA59 = 5250
WRIA60 = 6251
WRIA61 = 2791
WRIA62 = 7431

Site Selection Summary

Number of sites in sample 387,237

Attributes

Coordinate System

PROJCS["NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet", GEOGCS["GCS_North_American_1983_HARN", DATUM["D_North_American_1983_HARN", SPHEROID["GRS_1980",6378137.0,298.257222101]], PRIMEM["Greenwich",0.0], UNIT["Degree",0.0174532925199433]], PROJECTION["Lambert_Conformal_Conic"], PARAMETER["False_Easting",1640416.666666667], PARAMETER["False_Northing",0.0], PARAMETER["Central_Meridian",-120.5], PARAMETER["Standard_Parallel_1",45.83333333333334], PARAMETER["Standard_Parallel_2",47.33333333333334], PARAMETER["Latitude_Of_Origin",45.33333333333334], UNIT["Foot_US",0.3048006096012192]]

Bibliography

Diaz-Ramos, S., D. L. Stevens, Jr, and A. R. Olsen. 1996. EMAP Statistical Methods Manual. EPA/620/R-96/002, U.S. Environmental Protection Agency, Office of Research and Development, NHEERL-Western Ecology Division, Corvallis, Oregon.

Stevens, D.L., Jr. 1997. Variable density grid-based sampling designs for continuous spatial populations. Environmetrics, 8:167-95.

Stevens, D.L., Jr. and Olsen, A.R. 1999. Spatially restricted surveys over time for aquatic resources. Journal of Agricultural, Biological, and Environmental Statistics, 4:415-428

Stevens, D. L., Jr., and A. R. Olsen. 2003. Variance estimation for spatially balanced samples of environmental resources. Environmetrics 14:593-610.

Stevens, D. L., Jr., and A. R. Olsen. 2004. Spatially-balanced sampling of natural resources in the presence of frame imperfections. Journal of American Statistical Association:99:262-278.

Horn, C.R. and Grayman, W.M. (1993) Water-quality modeling with EPA reach file system. Journal of Water Resources Planning and Management, 119, 262-74.

Strahler, A.N. 1957. Quantitative Analysis of Watershed Geomorphology. Trans. Am. Geophys. Un. 38,913-920.

Photos

<none>

Documents

<none>