Skip Navigation

Management of Urban Riparian Greenspaces: A Retrospective Comparison of Oregon and Washington Municipalities

Project Leaders: Connie Ozawa, Alan Yeakley

This project examines how localized rates of riparian green space losses and gains affect individual and collective behavioral responses in the context of different state and local-level management approaches and the continuing disturbance press of population growth.

Broad Objectives:

  1. Contribute to understanding how different governance structures and management systems with varying constellations of public and private actor roles and responsibilities affect riparian health.
  2. Contribute to how information about the state of the resource affects individual and collective action responses.

Research Questions:

  1. What losses and gains in riparian vegetation have occurred in comparable cities undergoing population growth in Oregon and Washington (1990-2008) and what are the patterns of such changes?
  2. Is there a significant variation in the absolute and the patterns of losses and gains between the study cities during this time frame, and how have different management and regulatory strategies affected the magnitude, rate and patterns of losses and gains?
  3. How does information about the state of riparian resources, especially losses and gains occurring over time, affect individual and group behaviors and government policies and programs in each city?
  4. How do collective actions affect individual perceptions and actions and vice versa?


  1. We will conduct a comprehensive, retrospective analysis of gains and losses of all permanent streams in all study cities. This will be conducted by digitizing aerial photographs (1 ft. resolution) using a methodology refined through past research.
  2. We will review documents related to city and state level programs and policies that have governed land uses in riparian corridors effective 1990-2008. These accounts will be supplemented by information obtained through interview with resource managers and planners.
  3. A survey will be administered to elected officials, resource managers and residents of properties in the study areas to ascertain the extent to which information about the value of riparian vegetation and losses or gains over time in specific locations and localities affect their perceptions and intended behaviors regarding the resource.