High Definition Stream Survey information will improve the accuracy of habitat modeling.
Are you comfortable that the data obtained from a few site-based stream samples is adequate for your habitat modeling? Stream ecosystems are complex and conditions can change very rapidly, so habitat problems and their root causes can often be missed if assessments depend on site-based surveys. HDSS is designed to avoid this problem by collecting longitudinal geo-referenced data continuously over an entire stream corridor. Thorough documentation of all habitat issues will improve modeling effectiveness by incorporating more data about your stream.
Generally, habitat can be viewed as the home for stream animals. A healthy stream that can support a wide range of fish and invertebrates usually has a mix of different habitat types that provide the animals with their preferred living conditions.
HDSS documents changes to instream habitat conditions. Figure 1 displays a comparison of poor and excellent instream habitats. These locations are less than 1 mile apart on the same stream, and highlights how the variance in habitat conditions will be documented with longitudinal surveys.
HDSS also documents specific habitat conditions that can be reviewed in a dashboard format for context about the surroundings, or individually. Figure 2 shows an HDSS dashboard image that delineates habitat type (riffle, runs, and pools), substrate, substrate embeddedness, water depth, and instream cover. Scores for individual parameters can be combined to determine overall habitat condition.
Figures 3, 4 and 5 below show individual examples of habitat type, embeddedness, and substrate types, respectively.
High Definition Stream Surveys enable modeling that maintains healthy watersheds.
As a stakeholder in your watershed, do you know how your needs inter-relate with the needs of other watershed stakeholders? Increasing demand for water among public, industrial, and agricultural users threatens to reduce streamflow in many watersheds, but the impacts of competing demands on flow rates can be unclear. The HDSS process will produce more data, classifications relevant to all stakeholders, and reviewable documentation to support more robust and flexible instream flow models. Improving modeling results can help balance competing stakeholder needs with healthy stream ecosystems.