Willapa Bay 1:6000 / 1:3000 Scale Digital Atlas
Wildlife enthusiasts, nature lovers, field workers,
hikers, boaters, and stakeholders in the oyster industry will find these maps
very useful**.
Using
Willapa Bay Digital Atlas Maps
Spatial
Tide Predictions
The Willapa Bay Digital Atlas maps are unique in
their versatility. With a little effort,
a user is no longer limited to just knowing what the tide height will be at a
given day and time. Instead, he or she
can actually determine approximately where the water line will be located in
the bay at that particular time. To
locate the water line, match the tide height predicted at the time you choose
with the nearest tidal isolines, and that isoline will delineate the approximate
location of the actual water line at that particular time.
Color coded and labeled tidal isolines are provided
on these maps. The isoline heights are
Localized Mean Lower Lowest Referenced, and can be used in conjunction with the
appropriate NOAA tide predictions provided by NOAA Tides & Currents at
their 2009 Tidal
Station Locations and Ranges Oregon and Washington website. Because of the variability of MLLW in various
regions in the bay, best results are obtained by using the tide prediction
station found on each region’s webpage.
In areas where restricted waterways and/or rivers
are depicted, tides become more extreme, less predictable, and have greater
delay times than what is indicated by the nearest NOAA Tidal Prediction
Stations. In most cases, Mean Lower
Lowest Water (MLLW) and Mean Higher Highest Water (MHHW) diverge from mean tide
level for that area. Notes on each
region’s webpage help the user in addressing these issues. In some cases, reliability is too low to
justify delineating tidal isolines on the maps.
Other years are available at the NOAA website above,
and for convenience, links to 2005 to 2009 tides are provided on each regional
webpage (see below).
Latitude
/ Longitude Location
Some maps have inserts for features that extend
beyond the limits of the main map. On
each map and map insert, a lat/lon reference grid is displayed, with the DMS
(Degree, Minute, Second) location of the gridlines outside the border. This feature gives the user the capability to
coordinate the map with any GPS device or recording the location of a feature
of interest on the map for later reference. The DMS coordinate grid is labeled
in black for the main map, and yellow for the inserts.
Access
Information
These maps are focused primarily on the intertidal
zone of the bay. Most areas at or below
+16 feet local MLLW are included. Some
access information is provided in the form of both labeled paved roads and
unlabeled logging roads. It is
the responsibility of the user to obtain proper permissions for access. These maps are a great supplement for
information obtained from Google Earth or other map products provided by
tourism, parks, and other agencies. Note
that logging road data in is only approximately correlated with the airphotos.
Other
Information
Each map has a reference insert, locating on a
wider-area representation of Willapa Bay the extent of the map rectangle in
red. Any inserts are likewise
delineated, providing the user with a quick method of determining the exact
location and extent of each map.
The map number of the series is provided in the
upper right hand corner, outside the border.
Native projection information is provided along the
outside of the border at the bottom of each map.
Various caveats and legal disclaimers are provided
outside the border. Please observe them
rigorously. In the interest of the data
providers to whom we are grateful to for having provided these data. Therefore, please be sure to properly credit
them as well as the University of Washington / Olympic Natural Resources
Center.
Downloading
The Maps
At the bottom of this page, you will find a linked
list of regions. Each region’s webpage
has an index map showing the area in Willapa Bay covered by each map. The red numbers indicate each map’s order in
the Atlas and match the map number in the upper right hand corner of each
map. You can view the map in your
browser by clicking on the number or, if you want to save it for later use, right
click on the number and select ‘Save Target As…’.
Printing
The Maps
These maps are now being provided in *.pdf format to
improve the ease with which users print these maps.
The resolution is 450dpi for high quality display at
11 x 8.5 inch landscape prints at a 1:6000 scale. The 450dpi output was chosen as the best
balance between file size and the desire to enable the printing of 22 x 17
1:3000 scale landscape prints as well. These maps are designed to be printed
borderless, enabling the capture of DMS grid labels and other information
provided outside the map border itself.
The highest quality is obtained by printing 11 x 8.5 (1:6000) at 450dpi,
and 22 x 17 (1:3000) at 225 dpi. The
approximate size of each image is 14Mb.
Data
·
Upper, middle and lower intertidal zone:
Localized
MLLW referenced isolines are based on elevation enhancements of data derived
from 2002 NOAA CSC LiDAR implemented by
ONRC GIS using GPS data collected by USDA ARS, Newport OR.
Aerial
color infrared (CIR) imagery of intertidal zones was provided by USDA ARS,
Newport OR.
Oyster
beds are provided by Willapabay.org and include the Gibbs number.
·
Land features:
Terrestrial
color airphotos are the latest (2006) from the USDA National Agriculture
Imagery Program and have 1-meter resolution.
High
resolution road data is from Pacific County GIS.
Streams
are from ONRC’s enhanced hydrographic dataset based on the WA-OR Hydrology
Framework 1:24000 data.
Oyster
bed data are the latest currently available from Willapabay.org
Credits
Many thanks to Lee McCoy and Brett Dumbauld of USDA
Agricultural Research Service in Newport, Oregon for the provision and
permission to use their data for these maps. Without their data, these maps
would be just another set of maps, without their unique level of utility!
**These maps are not for navigational purposes. They should only be used as a general guide to locations and characteristics of features within the tidal zones of Willapa Bay. Safe field conduct is solely the user’s responsibility. No responsibility, implied or explicit, accrues to the UW/ONRC for providing these map products or to the providers of the data used to produce them.
Questions? Comments?
Contact Keven Bennett kbenet@u.washington.edu
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