General Information
Project area general description | The state of Colorado |
Are any areas excluded? | No, but some small closed basins in the SanLuis Valley were filled to show connectivilty |
Types of flow statistics available | Peak Streamflow Frequency, Annual and Monthly mean streamflow, minimum and maximum 7 day streamflow. |
ArcGIS version used for processing | Originally 9.1, with some updates using 9.2 |
Was TopoGrid used to process DEMs? | No. |
DEM and derivatives projection (general description) | UTM Zone 13, horizontal datum NAD 83, vertical datum NAVD 88 |
DEM and derivatives (fdr, fac, etc.) resolution | 10 m |
DEM source | 1/3-arc-second National Elevation Dataset (NED) http://ned.usgs.gov |
Hydrography source | National Hydrography Dataset (NHD) |
Hydrologic unit "walls" source | 8-digit HUCs only, based on draft WBD, 2007 |
Gage basin boundaries source | not used |
Interactive map snapping tolerance | 3 cells |
Basin characteristics computed using continuous parameter grids (CPGs) | BSLDEM10M, ELEV, EL7500 |
Basin Characteristics Methods and Sources
| Name | Description | Computation method | Data Source | Variable name in SIR 2009-5136 |
| BSLDEM10M | Mean basin slope computed from 10 m DEM, in percent | Area-weighted mean of slope grid | U.S. Geological Survey, 2007, 1/3-arc-second National elevation dataset, accessed August 13, 2007, at http://ned.usgs.gov/ | S |
| CSL1085LFP | 10-85 slope based on longest flow path computed using 10-m DEMs, in feet per mile | Computed | http://www.wcc.nrcs.usda.gov/ftpref/wntsc/H&H/NEHhydrology/ch15.pdf | |
| DRNAREA | Area that drains to a point on a stream in square miles | Polygon area | GlobalWatershed | A |
| EL7500 | Percentage of basin above 7500 ft elevation | Percent of area | U.S. Geological Survey, 2007, 1/3-arc-second National elevation dataset, accessed August 13, 2007, at http://ned.usgs.gov/ | A7500 |
| ELEV | Mean Basin Elevation, in feet | Area-weighted mean | http://hdsc.nws.noaa.gov/hdsc/pfds/ accessed March 7, 2016 | E |
| ELEVMAX | Maximum basin elevation, in feet | Computed | Computed from 10-meter DEM | |
| I24H100Y | Maximum 24-hour precipitation that occurs on average once in 100 years | Area-weighted mean | http://hdsc.nws.noaa.gov/hdsc/pfds/ accessed March 7, 2016 | |
| I24H2Y | Maximum 24-hour precipitation that occurs on average once in 2 years | Area-weighted mean | http://hdsc.nws.noaa.gov/hdsc/pfds/ accessed March 7, 2016 | |
| I6H2Y | Maximum 6-hour precipitation that occurs on average once in 2 years | Area-weighted mean | http://hdsc.nws.noaa.gov/hdsc/pfds/ accessed March 7, 2016 | |
| I6H100Y | Maximum 6-hour precipitation that occurs on average once in 100 years | Area-weighted mean | http://hdsc.nws.noaa.gov/hdsc/pfds/ accessed March 7, 2016 | 6P100 |
| LAT_OUT | Latitude of outlet | |||
| LC11BARE | Percentage of barren from NLCD 2011 class 31 | Percent of area | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LC11CRPHAY | Percentage of cultivated crops and hay, classes 81 and 82, from NLCD 2011 | Percent of area | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LC11DEV | Percentage of developed (urban) land from NLCD 2011 classes 21-24 | Percent of area | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LC11FOREST | Percentage of forest from NLCD 2011 classes 41-43 | Percent of area | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LC11GRASS | Percentage of grassland from NLCD 2011 class 71 | Percent of area | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LC11IMP | Average percentage of impervious area determined from NLCD 2011 impervious dataset | Area-weighted mean | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LC11SHRUB | Percentage of shrub scrub from NLCD 2011 class 52 | Percent of area | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LC11SNOIC | Percent snow and ice from NLCD 2011 class 12 | Percent of area | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LC11WATER | Percent of open water, class 11, from NLCD 2011 | Percent of area | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LC11WETLND | Percentage of wetlands, classes 90 and 95, from NLCD 2011 | Percent of area | http://www.mrlc.gov/nlcd2011.php accessed February 9, 2016 | |
| LFPLENGTH | Length of longest flow path, in miles | Computed | Computed using the LongestFlowPath ArcHydro tool | |
| LONG_OUT | Longitude of outlet | |||
| MINBELEV | Minimum basin elevation, in feet | Computed | Computed from 10-meter DEM | |
| PRECIP | Mean annual precipitation, 1971-2000, in inches | Area-weighted mean | Daly, Christopher, Nielson, R.P., and Phillips, D.L., 1994, A statistical-topographic model for mapping climatological precipitation over mountainous terrain: Journal of Applied Meteorology, v. 33, no. 2, p. 140–158, accessed August 15, 2007, at http://www.prism.oregonstate.edu/products/ | P |
| RCN | Runoff-curve number as defined by NRCS | Area-weighted mean | https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044171.pdf | |
| RUNCO_CO | Soil runoff coefficient as defined by Dhakal (2012) | Area-weighted mean | http://www.academia.edu/20858598/Development_of_Guidance_for_Runoff_ Coefficient_Selection_and_Modified_Rational_Unit_Hydrograph_Method_for_ Hydrologic_Design | |
| SSURGOA | Percent of area hydrologic soil 'A' defined by SSURGO | Percent of area | http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcs142p2_053627 accessed January 27, 2016 | |
| SSURGOB | Percent of area hydrologic soil 'B' defined by SSURGO | Percent of area | http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcs142p2_053627 accessed January 27, 2016 | |
| SSURGOC | Percent of area hydrologic soil 'C' defined by SSURGO | Percent of area | http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcs142p2_053627 accessed January 27, 2016 | |
| SSURGOD | Percent of area hydrologic soil 'D' defined by SSURGO | Percent of area | http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcs142p2_053627 accessed January 27, 2016 | |
| STORNHD | Percent storage (wetlands and waterbodies) determined from 1:24K NHD | Area-weighted mean | http://nhd.usgs.gov/ accessed May 17, 2016 | |
| TOC | Time of concentration - time required for runoff to travel from the hydraulically most distant point in the watershed to the outlet, in hours | Computed | Using equation 15-4b from https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=27002.wba, with computed values of BSLDEM10M, LFPLENGTH, and RCN |
The Colorado StreamStats introductory page here has additional information regarding the application, including links to reports, cooperators, and other explanatory information.