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<br />,",,-; --- <br />----'---- <br /> <br />. <br /> <br />.. J <br /> <br />GLOSSARY <br /> <br />Basin shane (Sh) Conceptually, the ratio between width and length of the <br />basin, dimensionless. To compute the value for basin shape the area of <br />basin is divided by the main channel length squared. <br /> <br />DrainaEe area (A) The area contributing directly to runoff, in square <br />miles. An outline of the drainage area should be drawn on topographic maps <br />and the outline planimetered to determine the area. When available, 7 1/2- <br />minute or IS-minute quadrangle maps should be used. <br /> <br />Forest cover (F) Forest cover is defined on topographic maps, expressed as <br />a percentage of the contributing drainage area. Forest cover can most <br />easily be determined with a transparent grid. The grid is placed on the map <br />and the number of squares covering forested areas are added together and <br />multiplied by the area of each square, calculated at the scale of the map <br />being used. (A transparent grid suitable to most map scales is enclosed in <br />a packet at the back of this report.) <br /> <br />Lake storaEe (Lk) Lake storage can <br />used to determine forest cover. <br />contributing drainage area. <br /> <br />be computed in a manner similar to that <br />Expressed as a percentage of the <br /> <br />Main channel slone (S) Mean slope of the channel computed between points <br />10 and 85 percent of the main channel length upstream from the point of <br />interest, in feet per mile. The main channel length is defined as the <br />stream bed extending from the site to the basin divide. The 10- and 85- <br />percent points are located on the map and the elevations of the points are <br />interpolated from the topographic contours. <br /> <br />Mean annual runoff (R) Average annual runoff during 1960- 76, in inches. <br />FrQm Climate of Minnesota, Part XII-The Hydrologic Cycle and Soil Water, <br />published by the Agricultural Experiment Station, University of Minnesota. <br />The value for this basin characteristic is determined by locating the <br />centroid of the basin on the map and interpolating between iso1ines. A <br />copy of this map is found on figure 4. <br /> <br />StoraEe (St) The storage area includes all lakes, ponds, and wetlands in <br />the basin, expressed as a percentage of the contributing drainage area. The <br />easiest technique to determine storage is by use of the grid method <br />described above for forest cover. <br /> <br />20 <br />