RGDSS_Task6-1_HistoricMonthlyModel_Drainage

Home Browse Search

The files used by ArcView may also be used in another GIS software package, MapInfo, by applying translator programs. The ArcView shape files (*.shp) were translated to MapInfo format (*.tab) using the Universal Translator software and ArcView to MIF translator software. This file translation preserves attribute information and geographic projection of individual files. Following analysis (discussed below), MapInfo files were then translated back to ArcView files. Drainage Area Delineation Gaged Locations Drainage areas for numerous stream flow gaging stations in the Rio Grande Basin were determined so that they could be used directly in the surface water model and for the development of proration factors at ungaged locations. The following describes the process used to estimate drainage areas at gaging stations. Hard-copy USGS topographic mapping (30 x 60 minute) was used to delineate contributing areas to gage stations based on topographic contour lines and locations of streams and rivers. Basin areas delineated on hardcopy maps were then digitized using MapInfo GIS. MapInfo SQL queries were used to calculate the digitized basin areas (square miles) and perimeters (miles). The calculated basin areas for each gaging station were entered into an attribute table and compared to USGS published basin areas (published basin areas are not available ("NA") for several newer stream flow gages). Slight adjustments were then made to several of the digitized areas in an effort to closely match published drainage area values (efforts were made to match published values within + or - 10 percent). The final drainage areas estimated for 52 gage stations located in the Rio Grande basin are shown in Table 1, and compared to published values. Many of these gages were used as baseflow locations in the model, depending on the adequacy of the historical streamflow data available for the gage. A map displaying the measured drainage areas for gaged and ungaged locations is included as Attachment 1. Table 1. GagelD 8213500 8214500 8216500 8217000a 8217000b 8217500 8218000 8218500 8219500 Drainage Areas at Gaged Locations Gage Name GIS Area mi2~ Rio Grande at Thirty Mile Bridge, near Creede, CO 163.86 North Clear Creek, Below Continental Reservoir, CO 48.86 Willow Creek at Creede, CO Rio Grande at Watson, below Creede, CO (area A) Rio Grande at Watson, below Creede, CO (area B) Rio Grande at Wagon Wheel Gap, CO Goose Cr near Wagon Wheel Gap CO Goose Cr at Wagon Wheel Gap, CO South Fork Rio Grande at South Fork, CO 8220000 Rio Grande near Del Norte, CO 8220500 Pinos Creek near Del Norte, CO 8223500 Rock Creek near Monte Vista, CO 8224113 San Louis Cr above Villa Grove, CO 8224500 Kerber Cr at Ashley Ranch near Villa Grove, CO 34.34 641.85 683.48 769.29 50.34 87.42 209.47 1318.01 68.63 32.85 11.20 39.85 USGS Area m i?~ 163.00 51.70 35.30 705.00 705.00 780.00 53.60 90.00 216.00 1320.00 53.00 32.90 11.20 38.00 C:\cdss\Task6-l.doc Drainage Areas and Proration Factors November 4, 1999 -Page 2 of 11