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r r. <br /> Topographic Effects <br /> Distances below are measured from the base. <br /> Crest <br /> elev: 103 <br /> dist: 450 <br /> Site L1P'J/ vb FJO(r.►/„Wtti, <br /> elev: 83 x <br /> dist: 335 ! � <br /> H/2 . �2��\ <br /> elev: 51.5 <br /> 1- <br /> dist: 240 �.-------'" <br /> 2D ;2tOC—E <br /> Base AX/5YM <br /> elev: 0 <br /> dist: 0 <br /> Exposure Category D <br /> Height above local ground z= 20 ft <br /> Location Relative to Crest Downwd <br /> Hill Shape 2-D Esc <br /> Height of Hill H= 103 ft <br /> Distance upwind of the crest to where the <br /> Lh= 210 ft difference in ground elevation is half of the height <br /> of the hill. <br /> x= 115 ft Distance upwind (or downwind)from the crest to <br /> Wind Speed-up over Hills, Ridges, and Escarpments <br /> 1) The hill, ridge,or escarpment is isolated and unobstructed upwind by <br /> other similar topographic features of comparable height for 100 times the Controlled <br /> height of the topographic feature or 2 mi.,whichever is less. This by. 10300 ft True <br /> distance shall be measured horizontally from the point at which the <br /> height H of the hill, ridge,or escarpment is determined. <br /> 2) The hill, ridge,or escarpment protrudes above the height of upwind <br /> terrain features within a 2-mi radius in any quadrant by a factor of two or 2-mi True <br /> more. <br /> 3) The structure is located as shown in Fig. 6-4 in the upper one-half of a <br /> hill or ridge or near the crest of an escarpment. True <br /> 4) H/Lh >= 0.2 H/Lh >= 0.49 True <br /> 5) H is greater than or equal to 15 ft for Exposure C and D and 60 ft for <br /> Exposure B H = 103 True <br /> Topographic factor <br /> If site conditions and locations of structures do not meet all the Krt= 1.73 <br /> conditions specified in Section 26.8.1 then Kzt = 1.0. <br /> Otherwise: <br /> KA= 1.73 K1= 0.47 <br /> K2= 0.86 <br /> K3= 0.79 <br /> Case Studies in Kzt Determination <br /> `1 , 2 <br />