File Geodatabase Feature Class
Tags
aquatic, fish, instream, habitat, hydrologic region, restoration, river, basin, planning, steelhead, stream, surveys, salmonids, coho, Chinook, watershed, Oncorhynchus, kisutch, mykiss, tshawytscha, biota, environment, inlandWaters
In-stream habitat data include measurements of a variety of physical and aquatic stream attributes that collectively reveal a great deal about stream condition for salmonids and trout. Characterizing and inventorying the physical conditions that define stream habitat for salmonids is an important part of the habitat restoration process. The California Department of Fish and Wildlife (CDFW) collects data on a number of physical attributes of streams and classifies these streams by one of several habitat types. The in-stream habitat data collection process involves two distinct steps; identifying channel type and assigning a habitat type. These in-stream habitat data are used for a variety of purposes including analysis of stream suitability for supporting salmonid populations, as part of larger and more complex watershed assessments, and to establish baseline conditions against which future assessments can measure change. They are a critical part of determining restoration priorities and identifying salmonid refugia. The California Salmonid Stream Habitat Restoration Manual, published by the CDFW, describes the process of using in-stream habitat data and other data and information for identifying streams with restoration potential and working through the stream restoration process.
The in-stream habitat GIS data included in CalFish consist primarily of those collected by the CDFW extending through most of Humboldt and parts of Mendocino counties. More recent data that was collected between 2010 and 2012 is available for Santa Barbara County. Other departments and organizations actively collect these data and as they become available, will be included in CalFish
WHAT EACH RECORD REPRESENTS
Each record in this dataset represents in-stream habitat unit level data summarized at the stream reach level. A habitat unit is the base level for the stream habitat surveys and is generally determined by the occurrence of riffle, run and pool sections along the stream. Stream reaches are determined by changes in stream channel type as described by Rosgen (1994).
California Department of Fish and Wildlife, Pacific States Marine Fisheries Commission, CalFish
DATA LIMITATIONS AND ASSUMPTIONS: For analytical purposes, users should assume that data collection methods were similar enough between streams, years, and observers to allow comparison of relative values. Observer bias is presumed low to non-existent. Unit-level in-stream habitat data are designed for suitability assessment of salmonid habitat at fine scales (stream segment). They should not be used for large watershed-level assessment tasks since no sampling designs were established for that purpose. In addition, the shapefiles comprising this data set are a visual representation of the data and have not been calibrated to existing stream data. Therefore spatial errors should be expected. KNOWN CAVEATS OF THE DATA: A significant scaling error often occurs in these data. Some of this error could be from mapping fine-scale ground measurements to a coarser map scale. The average in-stream habitat unit is approximately 55 feet (17 m) long while 1:24,000 scale maps may be accurate to the nearest 90 feet (30m). In most cases, distances measured at a fine scale will exceed measurements at a course scale (Mandelbrot, 1982). With this and other errors, habitat units for some streams may not be accurately placed on the map. Uncertainty of habitat unit placement on the map increases with distance upstream from the starting point. In many cases, the scaling error caused the length of the stream as measured in the surveys to exceed the apparent stream length mapped on the hydrography. For these instances, a scaling factor was applied automatically by the NCNCR 'Stream Habitat' application (contact Karen Wilson, Karen.Wilson@wildlife.ca.gov, for information on this program). Even after application of the scaling factor, instances of the length discrepancy exceeding 1000 feet were found in the data where the surveys covered several miles. Habitat conditions can change drastically both from year to year and within a season. Some of the factors to consider are variable stream flows (especially flood events), temperatures and silt loads. Use of the data with other time-dependent data such as stream biological inventories and salmon carcass surveys must be done with caution.
Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.
Extent
West | -124.483447 | East | -122.564872 |
North | 41.772468 | South | 38.348108 |
Maximum (zoomed in) | 1:5,000 |
Minimum (zoomed out) | 1:150,000,000 |
DATA LIMITATIONS AND ASSUMPTIONS: For analytical purposes, users should assume that data collection methods were similar enough between streams, years, and observers to allow comparison of relative values. Observer bias is presumed low to non-existent. Unit-level in-stream habitat data are designed for suitability assessment of salmonid habitat at fine scales (stream segment). They should not be used for large watershed-level assessment tasks since no sampling designs were established for that purpose. In addition, the shapefiles comprising this data set are a visual representation of the data and have not been calibrated to existing stream data. Therefore spatial errors should be expected. KNOWN CAVEATS OF THE DATA: A significant scaling error often occurs in these data. Some of this error could be from mapping fine-scale ground measurements to a coarser map scale. The average in-stream habitat unit is approximately 55 feet (17 m) long while 1:24,000 scale maps may be accurate to the nearest 90 feet (30m). In most cases, distances measured at a fine scale will exceed measurements at a course scale (Mandelbrot, 1982). With this and other errors, habitat units for some streams may not be accurately placed on the map. Uncertainty of habitat unit placement on the map increases with distance upstream from the starting point. In many cases, the scaling error caused the length of the stream as measured in the surveys to exceed the apparent stream length mapped on the hydrography. For these instances, a scaling factor was applied automatically by the NCNCR 'Stream Habitat' application (contact Karen Wilson, Karen.Wilson@wildlife.ca.gov, for information on this program). Even after application of the scaling factor, instances of the length discrepancy exceeding 1000 feet were found in the data where the surveys covered several miles. Habitat conditions can change drastically both from year to year and within a season. Some of the factors to consider are variable stream flows (especially flood events), temperatures and silt loads. Use of the data with other time-dependent data such as stream biological inventories and salmon carcass surveys must be done with caution.
Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.