Habitat quality was estimated in a relatively comprehensive manner throughout the subbasin during development of a NPPC Presence/Absence Database. Habitat quality ratings were compiled by stream reach and are qualitative and species specific. Habitat quality for each species was rated as excellent, good, fair, or poor. For the purpose of this assessment, NPPC stream reach ratings of habitat quality were subsequently summarized within each applicable 6th field HUC by assigning numerical values to each rating, and calculating the weighted average for each HUC using segment length as the weighting variable.
These data were submitted to the Columbia River InterTribal Fish Commission (CRITFC) in 2006 where this subset of the original data was created. Metadata was also written by CRITFC, and these data were archived along with othe related information for long term data management purposes.
Data files with NPPC (Streamnet) presence/absence database info (includes habitat and CC) linkable to a stream layer were obtained from Evan Brown of IDFG. As per discussions with Bart Butterfield (12/13/00), the data is linkable to the Streamnet hydrography layer using a 15 digit River Reach Number (RRN), not the 17 digit RRN currently defined in the hydrography layer. The 15 digit RRN was compiled using the 4th code HUC number (8 digits), the 'seg' number (3 digits), and the CRMI number (4 digits) found in the Streamnet hydrography layer. These 15 digit RRNs were then used to link data from the NPPC presence/absence database directly to the hydrography layer at a scale of 1:250,000. The link table containing the 15 digit RRNs is titled 'streamnet_link_table.dbf' and the appropriate info is in the column titled 'RR_Num'.
Data Manipulations/Summary: 1) The RR_Num (streamnet_link_table.dbf) was linked to the 1:100k Streamnet hydrography layer (streams_bs.shp) and saved as a separate shapefile (Snstreams_w_links.shp). 2) Snstreams_w_links.shp was then summarized by RR_Num to re-create the 1:250k hydrography layer originally used by Streamnet and was saved as 'SN_Streams_by_rrnum.shp'. 3) 'SN_Streams_by_rrnum.shp' was then overlain with the 6th field HUCs. For chinook or steelhead producing streams (ONLY), stream reaches which crossed between HUCs were manually edited to break each reach into segments which were each contained within a single HUC. Due to difficulties in editing the existing shapefile, X-tools was used to convert multi-part shapes to single shapes (resulting in ability to successfully edit reaches). X-tool was then used to recalculate the length of all stream segments. The edited layer is titled 'NPPC_prod_streams_clipped_to_hucs.shp'. This file forms the basis for subsequent linking, plotting and summarizing all NPPC data from the presence/absence database. 4) NPPC presence/absence database information was separated by species to form 'sthd_reach_data.dbf' and 'chinook_reach_data.dbf'. These files were subsequently linked to 'NPPC_prod_streams_clipped_to_hucs.shp' resulting in the production of two new shapefiles; 'SteelheadCC3.shp' and 'ChinookCC3.shp'. 5) Within both 'SteelheadCC3.shp' and 'ChinookCC3.shp' new columns were created for later use in summarizing information by HUC. Columns were: HabQ_No = Habitat quality rating converted to numerical value with 4 as excellent and 1 as poor; Habxleng = multiplies habQ_no by segment length; Proportion = segment length/original reach length; Adj_CC = adjustment to CC estimates based on Rich et al. 1992 (applies to chinook only); SegCC = proportion multiplied by the estimate of CC or Adj_CC. 6) Using X-tools, stream reaches were converted to centroids to minimize issues associated with reprojection, etc… while summarizing data by HUC. Two files were created; SH_cc_centroids.shp and CH_cc_centroids.shp. 7) Centroids were spatially joined to HUC information, and all records without associated information from the presence/absence database were deleted (end layers represent only those centroids associated with fish production reaches). New shapefiles were created; Sh_cc_cntrd_huc.shp and Ch_cc_cntrd_huc.shp. 8) Shapefiles created in step (7) summarized by HUC and new files created that included the following; Species, Sum of Length, Sum of Hab x Leng, Sum of Seg_cc. Summary tables are titled Sh_huc_summ.dbf and Chin_huc_summ.dbf. 9) Within Sh_huc_summ.dbf and Chin_huc_summ.dbf, a column was added summarizing weighted (by segment length) habitat quality within each HUC; Column is 'Wt_habQ' and computed as Sum of Hab x Leng divided by Sum Length. 10) These summary tables were joined to the HUC layer and new shapefiles created representing summary of NPPC presence/absence database info by 6th field HUC. New shapefiles are titled 'NPPC_shdata_by_HUC.shp' and 'NPPC_chindata_by_HUC.shp'.
Assumptions Associated with Data Manipulations/Summary: 1) Within any given reach, the carrying capacity is evenly distributed throughout (i.e. dividing a reach into two equal segments also equally divides the original CC between them). This same assumption is made by IDFG in the Parr Monitoring Database calculations when estimating carrying capacity and associated percent of carrying capacity realized in monitored reaches. 2) Within any given HUC, the reaches presented in the presence / absence database represent a complete picture of the distribution of spawning and/or rearing areas for both chinook and steelhead. This assumption is drawn from the intent and methods used to compile the original database.
3) 'SN_Streams_by_rrnum.shp' was then overlain with the 6th field HUCs. For chinook or steelhead producing streams (ONLY), stream reaches which crossed between HUCs were manually edited to break each reach into segments which were each contained within a single HUC. Due to difficulties in editing the existing shapefile, X-tools was used to convert multi-part shapes to single shapes (resulting in ability to successfully edit reaches). X-tool was then used to recalculate the length of all stream segments. The edited layer is titled 'NPPC_prod_streams_clipped_to_hucs.shp'. This file forms the basis for subsequent linking, plotting and summarizing all NPPC data from the presence/absence database. 4) NPPC presence/absence database information was separated by species to form 'sthd_reach_data.dbf' and 'chinook_reach_data.dbf'. These files were subsequently linked to 'NPPC_prod_streams_clipped_to_hucs.shp' resulting in the production of two new shapefiles; 'SteelheadCC3.shp' and 'ChinookCC3.shp'. 5) Within both 'SteelheadCC3.shp' and 'ChinookCC3.shp' new columns were created for later use in summarizing information by HUC. Columns were: HabQ_No = Habitat quality rating converted to numerical value with 4 as excellent and 1 as poor; Habxleng = multiplies habQ_no by segment length; Proportion = segment length/original reach length; Adj_CC = adjustment to CC estimates based on Rich et al. 1992 (applies to chinook only); SegCC = proportion multiplied by the estimate of CC or Adj_CC. 6) Using X-tools, stream reaches were converted to centroids to minimize issues associated with reprojection, etc… while summarizing data by HUC. Two files were created; SH_cc_centroids.shp and CH_cc_centroids.shp. 7) Centroids were spatially joined to HUC information, and all records without associated information from the presence/absence database were deleted (end layers represent only those centroids associated with fish production reaches). New shapefiles were created; Sh_cc_cntrd_huc.shp and Ch_cc_cntrd_huc.shp. 8) Shapefiles created in step (7) summarized by HUC and new files created that included the following; Species, Sum of Length, Sum of Hab x Leng, Sum of Seg_cc. Summary tables are titled Sh_huc_summ.dbf and Chin_huc_summ.dbf. 9) Within Sh_huc_summ.dbf and Chin_huc_summ.dbf, a column was added summarizing weighted (by segment length) habitat quality within each HUC; Column is 'Wt_habQ' and computed as Sum of Hab x Leng divided by Sum Length. 10) These summary tables were joined to the HUC layer and new shapefiles created representing summary of NPPC presence/absence database info by 6th field HUC. New shapefiles are titled 'NPPC_shdata_by_HUC.shp' and 'NPPC_chindata_by_HUC.shp'.
** Final Processing by CRITFC **
1) Defined correct projection for shape file (UTM, Zone 11, NAD 27)
2) Related Steelhead shapefile to Chinook shapefile on HUC6 attribute
3) Added two new attributes to show habitat quality by species and populated with information from related shapefiles
4) Dropped all other attributes except HUC6