Stressors-Aquatic Habitats

Step Wise Guide

Aquatic/Riparian Habitats

Identify locations where one or more environmental stressors overlap with or intersect valuable or sensitive fish habitats(or sensitive terrestrial habitats)

One goal of watershed or landscape assessments is to determine how priority stressors affect conservation targets and how to mitigate their effects. Before this can be effectively accomplished, agencies and other stakeholders must first identify, rank, and map locations where stressors, singly and in combination, overlap key aquatic and terrestrial habitats. NetMap provides the ability to do so.

Step 1: Use various NetMap tools to map and classify aquatic resource values including fish habitats, beaver habitats, biological hotspots, and floodplain/riparian habitats (refer to the other components of the Step Wise Guide for Aquatic and Riparian Habitats). The stressor-habitat analysis in NetMap is not limited to aquatics, but can be extended to the terrestrial environment as well. For example, terrestrial habitats can include animal and plant diversity, which in NetMap, can be summarized at the scale of drainage wings and represented in the channel network. Other types of terrestrial stressors can also be summarized and displayed in this way including fire risk, burn severity, downscaled climate change predictions, grazing (allotments) and energy development (roads, drilling pads, pipelines).

When importing new types of land cover information (fire risk, grazing etc.), Go To NetMap Basic Tools > Data Management > Import Data. Following its importation, then Go To NetMap Basic Tools > Data management > Custom Attributes; here is where you name your data for later use in NetMap. To capture the data at the scale of drainage wings and to place that information into stream segments and to route downstream (or upstream). Go To NetMap Basic Tools > Attribute Aggregation > Routing of Hillslope Attributes.

The newly imported and named data will show up at the bottom of the drop down menus of attribute names in all of the tools, under "custom attributes".

NetMap's data structure allows the cumulative distribution of any watershed or resource use attribute to be calculated at any scale. This allows terrestrial information (such as erosion potential or road and pipeline density (km/km²)) or channel segment data to be evaluated in terms of exceedence probability. For example, a manager can quickly search for a habitat-stressor intersection that involves the top 1% of fish habitat quality (e.g., 99^th percentile = 1% exceedance) and the top 5% of road density, or the top 5% of predicted climate change (such as reduced snowmelt runoff) with the top 5% of wildfire risk. In effect, planners search for locations where stressor extremes overlap, singly or in combination, with the most sensitive (highest exceedance) habitats.

Step 1: Go to NetMap Basic Tools > Risk Assessment > Stream Segment Overlap. First, choose an attribute for display which can be one of the attributes you are using in the overlap analysis or an independent one. Next, go to the drop down lists and select the habitat stressor pair of attributes you are interested in, such as fish habitat quality (i.e., steelhead intrinsic potential) and erosion potential, road density etc. (from the second drop down list). Then, on the left hand side of the attribute selection, select the percentile of the distribution you would like to search for (top 1%, 5%, 15%, etc.). Do the same for the next attribute. Then calculate.