A THREE-TIERED SYSTEM FOR MONITORING FLUVIAL SYSTEMS

The National Park Service is collaborating with the Geological Society of America to produce a manual to guide park scientists and other public land managers for monitoring geological processes. Monitoring data will be used to assess the status and trends of stream resources in parks to help guide management decisions. We are constructing a three-tiered system for monitoring dynamic characteristics of fluvial systems pertaining to six “vital signs”: 1) drainage basin land cover, 2) drainage basin hydrology (including rainfall, runoff, and stage/discharge relations), 3) channel planform, 4) channel longitudinal profile, 5) cross-section geometry, and 6) sediment transport rates. Our system will enable land managers to select methods for monitoring each vital sign based on 1) the relevance of each vital sign to their specific streams and regions, 2) the time commitment required for each method, 3) the level of expertise available for data collection and analysis, and 4) the cost of requisite equipment and technology.

The lowest level of complexity utilizes simple observations that can be made by individuals or small crews with minimal supervision. These include methods such as basic hydrological measurements, repeat photography, and descriptive ordinal classification schemes. The second level of complexity incorporates measurements that can be made using simple tools, probes, and imagery. These methods would require small crews (2 or 3 people) with little technical training. This level includes measurements of water surface width and depth, channel cross sections, point counts of bed load material, riparian hydrogeology, rates of rainfall, and basic spatial analysis using topographic maps and aerial photographs. The highest level of complexity involves methods that require more supervision and analysis by trained geoscientists. These include techniques such as repeated surveys of channel form, advanced spatial analysis techniques, and collection and analysis of sediment load samples. Our system is designed to complement reach-scale channel measurements while focusing on the role of the stream as a dynamic component of a watershed. We provide examples of our approach using data from streams in the humid south east, the arid west, and the urbanized mid-Atlantic region.