1.3 How can indicators be used?

Indicators can be used to tell us about status and trends for a variety of attributes of different systems. They help us understand system condition and can inform decisions affecting management and restoration of valued attributes and processes. To be effective, they are usually organized into structures that help users clearly understand their meaning. For example, water characteristics such as temperature, dissolved oxygen (DO), pH, and concentrations of suspended sediments are not necessarily intuitively-understood by a non-technical audience but can be combined into a more user-friendly index of water quality to help regulators and the public understand water quality status and trends and whether there might be a need for particular regulations or investments in infrastructure.

Indicators Around the World
To position this study in a global context, 20 indicator frameworks from around the world were analyzed, including the types of EWAs represented, the types of indicators used, and their coverage of different spatial scales. We found that the attribute categories of chemical/physical condition, biotic condition, hydrology/geomorphology, and social condition were well-represented among the compared frameworks.

The >900 indicators from all 20 frameworks reviewed were categorized within each of the EWAs of the WAF (e.g. Landscape Condition, Biotic Condition, Chemical and Physical Characteristics, etc.). This categorization allows for comparisons among the different approaches. Graph A shows the number of frameworks with indicators in each WAF attribute category. Graph B shows the number of indicators from all frameworks categorized within each WAF attribute category.

A majority of the indicators among all 20 frameworks analyzed were represented in 4 WAF attribute categories: chemical/physical condition, biotic condition, hydrology/geomorphology, and social condition. The indicator frameworks did not effectively cover the WAF attributes of ecological processes, natural disturbance, economic condition, or landscape condition.

The system we used to develop and organize indicators is called the WAF, which was adopted in 2007, by the state of California as part of a strategy to inform and guide watershed management. It is based upon the US Environmental Protection Agency’s (USEPA) Science Advisory Board’s (SAB) approach (SAB, Young and Sanzone, 2002). The SAB system provides a framework for organizing indicators into categories termed “essential ecological attributes” (EEAs). The WAF adds social and economic categories to the EEAs and re-frames these attributes as “essential watershed attributes” (EWAs), creating an evaluation framework for the integrated natural and human systems in watersheds (Figure 1.2). Missing from the SAB approach is guidance for comparing indicator values to a desired or reference condition and guidance for aggregation of normalized values into “scores” for the EWA/EEAs and other possible aggregations. The SAB framework also suggests that indicator information corresponding to measurable objectives can be extracted from the framework, however, how that can occur is not described in any detail. The WAF approach we propose here fills these gaps, describing the use of the framework to organize condition indicators, a normalization approach drawn from the scientific literature, and an approach for both measuring condition in system categories (e.g., EWAs) and performance relative to desired goals and objectives for the system.

Figure 1.2. California Watershed Assessment Framework showing Essential Watershed Attributes

The WAF approach is founded on metrics and indicators (see Appendix A: Glossary of Terms for explanation of what these terms mean) that are organized into a hierarchical structure corresponding to aspects of natural and human systems that are termed system “attributes.” The WAF is not the only way to organize these measures of environmental (both human and natural) condition. Information describing ecological, economic and social conditions could also be organized according to the goals that society sets for these conditions.