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thicknesses used to calculate K values reported in Phase 2 Task 37 were based on the <br />sand thickness maps developed during Phase 1 and have since been updated. The K <br />values presented herein supersede those reported in the Phase 2 Task 37 TM (CDM <br />2005). <br />1.2.5 Data Analysis <br />Analysis of the Denver Basin Region aquifer property data was performed by combining <br />data derived from aquifer pumping tests, specific capacity tests, and laboratory tests into <br />one data set. To convey the range in data values in a graphic format, the individual <br />aquifer K data are presented in four color coded groupings rather than in contoured <br />form. It is anticipated further analysis and processing will be used in preparation of the <br />aquifer property data prior to input into a groundwater flow model, which would <br />include development of contoured distributions of K values from the point values <br />provided herein. Some of the anticipated activities will involve adding engineering <br />control points, smoothing, and other techniques that will facilitate model input and <br />calibration. The information analyzed and presented in this TM represents raw field <br />data so that it accurately conveys the aquifer data obtained from the Denver Basin <br />Region. <br />To create the four quartile-based groupings for presentation purposes, the data were <br />sorted by aquifer using the aquifer abbreviations provided in HydroBase. Statistical <br />analyses were performed by type of aquifer test (pumping, specific capacity, and <br />laboratory) to determine the data ranges and quartile distribution groupings of data <br />from each aquifer and by each data type. Each quartile grouping contains an even <br />number of data points with each grouping based on the numeric range of the K values. <br />The data groupings are defined with blue representing values greater than the 75th <br />percentile (the highest 25 percent), green representing the 75th to 50th percentile values, <br />orange representing the 50th to 25th percentile, and red representing the lowest 25th <br />percentile of data by K value. All of the individual data are contained in ArcGIS <br />shapefiles, included electronically as part of the Final TM. <br />Data obtained from Robson (1983) represents a significant data source but information <br />was not available to assign the individual data points to either the upper or lower <br />aquifer units of the Dawson and Arapahoe Aquifers. To maximize use of this data, the <br />Robson (1983) data were included in development of quartile groupings and are <br />presented graphically with other data that could be assigned to either the upper and <br />lower units of the Dawson and Arapahoe Aquifers. This results in duplicate posting of <br />the Robson (1983) data and over counting of the individual aquifer data points but was <br />felt to be the best way to maximize use of this previously published data resource. <br />Robson (1983) data that fall outside of the divided portions of the Dawson and <br />Arapahoe Aquifers are presented with data from the lower units of these aquifers and <br />are not distinguished from data obtained from other sources. Section 3 presents the data <br />mapping and analysis. <br />SPDSS Phase 2 Task 43.2 TM -Final 14 <br />2/ 13/ 2006 <br />