Item 1: Supply of Commercial and Industrial Land in Lane County

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Appendix B Summary of Data Sources DATABASE STRUCTURE The challenge with this database system is integrating data elements with existing GIS coverages. ECO used a relatively simple relational database design. The data elements are housed within an MS Access database that can link to key GIS coverages. Figure B-1 provides a list of tables included in the database. It includes the table name, the data source, a brief description of what the table will contain, and the geographic extent (tax lot/land use polygon or both). The central element of the database is a table housing the total land base for this study (Land Base in Figure 1). This table contains a single record for every land use polygon meeting the criteria for being included in this study of commercial and industrial land. ECO was directed by the T AC to use the land use polygon file from LCOG as the basis for the analysis. It was agreed upon by the TAC to use the land use GIS coverage, rather than the tax lot GIS coverage, as it provided a higher level of granularity in terms of identifYing portions of tax lots that are currently in use versus portions of the tax lot that are not. The Land Use table represents the full universe of land that will be looked at during this project. As such it was important to cast as broad a net as possible to ensure the inclusion of any land that has the potential to meet the criteria for this study. Since much of the data being collected was derived from GIS spatial analysis, once the core database is designed and data begins loading into the repository tables, it becomes very difficult and time consuming to backtrack and add new land into the study. However, removing land that was initially included, but is later identified as not a part of this study is relatively easy. As it is the center of the database, much time has been spent, working with the T AC to finalize the criteria for selecting the land base. ECO worked with three key GIS files from LCOG to produce the land base: (1) the Lane County land use polygon coverage; (2) the Metro land use polygon coverage; and (3) the newly adopted Metro Plan Designation coverage. For the Metro area, commercial and industrial plan designation classes that were to be included in the land base were identified by City of Eugene and City of Springfield. A spatial query was applied to the Metro Plan Designation coverage and a GIS overlay operation was performed between this file and the Metro land use polygon to arrive at the land base for the metro area.