Developing Rapid Methods for Analyzing Upland Riparian Functions and Values

Abstract

Regulators protecting riparian areas need to understand the integrity, health, beneficial uses, functions, and values of this resource. Up to now most methods providing information about riparian areas are based on analyzing condition or integrity. These methods, however, provide little information about functions and values. Different methods are needed that specifically address this aspect of riparian areas. In addition to information on functions and values, regulators have very specific needs that include: an analysis at the site scale, low cost, usability, and inclusion of policy interpretations. To meet these needs a rapid method has been developed that uses a multi-criteria decision matrix to categorize riparian areas in Washington State, USA. Indicators are used to identify the potential of the site to provide a function, the potential of the landscape to support the function, and the value the function provides to society. To meet legal needs fixed boundaries for assessment units are established based on geomorphology, the distance from “Ordinary High Water Mark” and different categories of land uses. Assessment units are first classified based on ecoregions, geomorphic characteristics, and land uses. This simplifies the data that need to be collected at a site, but it requires developing and calibrating a separate model for each “class.” The approach to developing methods is adaptable to other locations as its basic structure is not dependent on local conditions.

Appendices

Appendix A

Appendix B

Summary of Data Collection by Multiple Users

Indicators used in rapid methods need to be chosen so that most users will answer the questions on the field form correctly. Table 5 below summarizes the data collected from multiple users during the process of choosing indicators and metrics for the riparian method. Untrained users were given a manual describing the indicator and how to collect data about it. Data were also collected by the team who developed the indicator and the metrics. At the end of each site visit the data were compiled and the results from each user were discussed and compared to the data collected by the “expert” team. Changes to indicators and metrics were made based on the discussions, and some indicators that had the highest variation among users were dropped. Thus, the metrics on the final field form in Appendix A are not exactly the same as those listed below. Seven different sites were visited by 49 users. Each user, however, collected data at only one site.

Table 5 Summary of data for field metrics collected by untrained users. Indicators were sampled at 5 sites by 19 users unless noted

Metrics that require a user to collect information from existing sources on the internet or from existing databases were not tested. For example, data on the water quality of adjacent bodies and on the priority habitats and species in the area could not be determined in the field. It was assumed that users who access the information will answer the questions with less variability than the field questions.

No training was provided when developing the indicators to test the “worst case” scenario and to provide relatively unbiased feedback on the feasibility of using different indicators and metrics. Thus, we do not have data on the variability in data for the riparian method among trained users. The variability, however, is expected to decrease when a proposed training program is instituted; based on the experience we have gained with the wetland rating system (Hruby 2004a,b). Table 6 summarizes the data collected on wetland ratings after users were trained. The wetland rating system categorizes wetlands into one of four categories rather than three, but many of the indicators used are similar to the ones in the riparian method.

Table 6 Comparison between trained users and the “expert” team in determining wetland category using the Washington State Wetland Rating Systems (Hruby 2004a,b)

Appendix C

Table 7 Calibration data for the riparian model of the Alluviated Lowlands in Western Washington