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Show Units and terminology Some of the terms used in this report and the units in which some parameters are expressed represent a departure from earlier practice. These new terms and units are described in the following paragraphs. The hydraulic conductivity of a material is the ability of the material to transmit water and was formerly called the field coefficient of permeability. Hydraulic conductivity in this report is expressed in cubic feet of water per day per square foot of cross- sectional area ( ft3/ d/ ft2), rather than in gallons per day per square foot. One cubic foot is about 7V2 gallons. Similarly, the ability of an aquifer as a whole to transmit water is the transmissivity of the aquifer and replaces the older term coefficient of transmissibility. Transmissivity is given in cubic feet of water per day per foot of aquifer width ( ft3/ d/ ft) rather than in gallons per day per foot. Note that hydraulic conductivity is a property of the aquifer material, whereas transmissivity is a property of the aquifer as a whole. The figure for transmissivity is equal to the product of the figure for hydraulic conductivity of the aquifer material and the saturated thickness of the aquifer. The water temperatures in the text and tables are given in degrees Celsius (° C) rather than in degrees Fahrenheit (° F). In the text, the equivalent temperatures in ° F are given in parentheses. The reader who is not familiar with the Celsius scale may find the following table useful for converting temperature data from the tables of basic data to the more familiar Fahrenheit scale. TEMPERATURE- CONVERSION TABLE For conversion of temperature in degrees Celsius (° C) to degrees Fahrenheit (° F). Conversions are based on the equation, ° F = l. 8° C + 32; temperatures in ° F are rounded to nearest degree. Underscored equivalent temperatures are exact equivalents. For temperature conversions beyond the limits of the table, use the equation given, and for converting from ° F to ° C, use ° C = 0.5556 (° F - 32). The equations say, in effect, that from the freezing point ( 0° C, 32° F) the temperature rises ( or falls) 5° C for every rise ( or fall) of 9° F. ° C ° F ° C ° F ° C ° F ° C ° F ° C ° F ° C ° F ° C ° F - 20 - 19 - 2 - 10 - 9 14 16 0 + T 32 34 10 11 50 52 20 21 68 70 30 31 86 88 40 41 104 106 - 18 0 - 8 18 2 36 12 54 22 72 32 90 42 108 - 17 + 1 - 7 19 3 37 13 55 23 73 33 91 43 109 - 16 3 - 6 21 4 39 14 57 24 75 34 93 44 111 - 15 - 14 5 7 - 4 23 25 5 " 6 41 43 15 16 59 61 25 26 77 79 35 36 95 97 45 46 1.13 115 - 13 9 13 27 7 45 17 63 27 81 37 99 47 117 - 12 10 - 2 28 8 46 18 64 28 82 38 100 48 118 - 11 12 - 1 30 9 48 19 66 29 84 39 102 49 120 Chemical analyses throughout this report are expressed in milligrams per liter ( mg/ l) rather than in parts per million ( ppm). For water having a total concentration of dissolved solids of less than about 7,000 mg/ l ( which includes all water in the area described in this report), milligrams per liter can be considered equivalent to parts per million. Milliequivalents per liter ( meq/ l) are calculated by dividing the concentration in milligrams per liter by the combining weight of the ion; for graphical presentation, milliequivalents per liter is a more convenient unit than milligrams per liter. 53 |
