Effects of Land Use Policy on Urban Growth Rates in the Willamette Valley, Oregon
This study seeks to determine the correlation between changes in statewide land use planning policies and the resulting periods of high or low urban growth in the Willamette Valley, Oregon using automated classification methods and freely available satellite imagery. To protect its farms, forests and open spaces, Oregon became the first state to implement a comprehensive land use planning policy in 1973. Ballot measures and legal rulings that have passed in the intervening decades have in some cases expanded and in other cases reduced the state’s power to enforce its land use goals. This study aims to discover whether changes in urban growth rates on the ground, as identified by Landsat satellite imagery, correspond with legislative changes. The shifting landscape weakly reflects the effects of ballot measures and local zoning decisions as they have bolstered or weakened Oregon’s urban growth management system. Though no statistically significant correlation appeared in this study, periods of unusually high or low urban area did generally follow the implementation of a corresponding new policy.