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Show SIMPLE METHOD OF MEASURING A RIVER The Geoogical Survey, Department of the Interior, receives many letters inquiring for some easy method of determining the approximate flow of streams or small rivers, where regular regu-lar river-measuring instruments are not available. The method described below is considered useful under such j conditions. ; To ascertain the velocity of the : stream choose a pace where the i channel is straight for 100 or if pos- j sible 200 feet and where it has a nearly constant width and depth and j smooth current. Lay off on the bank the center 50 or 100 feet of the i straight reach of the stream marking: each end. Then allow small chips i to float down the stream noting the BKAVrn COUNTY NEWS j I'ulilislnMl Kvt'i-y Friday at Milford, Utah Karl S. Carlton Editor Subscription, a var $2.u0 Payable in Advance Entered in the Post Oifiee at MiKord j Utah, as second class mail" matter, j time required to traverse the di.s- i tance laid off on the bank. j The surface velocity in feet per j second is obtained by dividing the j distance in feet passed over by the j chips by the time in seconds it takes j them to travel this distance. The average result of several such tests, ma le at different positions from bank to bank, will five the mean or average aver-age surface velocity of the stream. This result multiplied by 0.S gives very nearly the average velocity of the entire flow of the stream. This is the first step. To obtain the area of the cross section of the stream, stretch a tape from shore, to shore and take the depth of the stream at short intervals 2 or 5 feet. The average of these depths may be assumed as the average aver-age depth of the stream at this point. This average in feet multiplied by the total in feet will give the area of the cross secton of the stream in square feet. The volume of the discharge of the stream is now found by multiplying this cross section figure by the average aver-age velocity, feet per second, as obtained ob-tained by the chip measurements,, the result being the discharge in second feet, or, in other words, the number of cubic feet of water flowing past the point of measurement each second. |