Willamette Basin Floodplain Map

(click map for larger image)


Introduction to the SLICES Framework

The Slices Framework is intended for use in making decisions about conservation and restoration in the Willamette River floodplain.  It makes use of distinct spatial units for tracking change in the floodplain. The first of these units are 1 kilometer long slices drawn at right angles to the floodplain, first put forward in the Willamette River Basin Planning Atlas (Ch. 8 pp. 131-147 in Hulse, Gregory and Baker 2002). The second of these units are 100m subdivisions of the original 1 km slices, with ten 100m slices in each 1 km slice.

We provide access to three types of information, each of which uses the slices as a reporting unit for processes and patterns that are critical to native ecosystem function. These three types of information are:


PDF Maps
A set of 20 PDF documents showing slice boundaries and slice numbers superimposed on contemporary air photographs;

Tabular Attribute Data
A spreadsheet that reports amounts of key processes and patterns by slice and how they vary over time;

GIS Data
ArcGIS data (provided as a shapefile and as a geodatabase) that contains similar information as the PDFs and spreadsheet, but in one place and with greater analytic capabilities.


Using the Slices Framework consists of finding the portion of the floodplain you’re interested in and opening the relevant PDFs, spreadsheet, or ArcGIS file that best suits your purposes. 

The PDFs are a series of 20 single images, each combining an air photo with taxlot boundaries, major road names and 1 km and 100m slice boundaries and numbers. Together, they cover the entire pragmatic floodplain of the Willamette River. We define the pragmatic floodplain as the zone subject to periodic flooding that is bounded by significant infrastructure (e.g. highways, residential areas, etc.).

The spreadsheet quantifies, for each 100m slice, the amounts of key patterns and processes circa 2000 and projected for circa 2050 by the Pacific Northwest Ecosystem Research Consortium’s Conservation 2050 scenario – used here as a guiding vision for a restored Willamette River floodplain.

The ArcGIS shapefile requires specialized hardware and software to use, but for those with access to those tools, it offers more ways to query and make use of the slices information than the PDFs or spreadsheet.