Laserfiche WebLink
<br />32 <br /> <br />forming conditions pr~vail, adjustments in the values of Cs and m <br /> <br />probably would be necessary. <br />Since cross-sectional properties of different streams are subject <br /> <br />to considerable variation, the values for C and m must be <br />s <br />determined empirically. Determination of the constants must be done <br /> <br />for each given stream type. Observation of a number of different <br /> <br />stations for each type stream are required. The coefficient and the <br />exponent could be determined and compared for each cross-section in <br /> <br />a given stream type. Such a set of observations was not possible <br /> <br />during the course of this study since insufficient time was available <br /> <br />for establishing and rating measurement sections. <br /> <br />In order to achieve results for this study, it was assumed that <br /> <br />the control section behavior would be similar enough to a weir such <br /> <br />that a form of the weir equation would apply. In the weir equation, <br /> <br />setting LH equal to A, and C equal to <br /> <br />C <br />s <br /> <br />gives <br /> <br />Q = C A HO' 5 <br />s <br /> <br />(3-2) <br /> <br />Then, using m = 0.5, the equation can be solved at several of the <br /> <br />pertinent sections for C An average C equal to 2.46 was <br />s s. <br />calculated by comparison to observed water surface levels at six <br /> <br />stations. The equation with constants was incorporated into the <br /> <br />computer program as subroutine CONTROL. <br /> <br />As previously mentioned, problem solution is routed into this <br /> <br />subroutine when an energy balance is apparently unattainable. Solution <br /> <br />proceeds by using the last calculated value for area and the <br /> <br />corresponding value of stage for trial entry into Eq. (3-2). A trial <br /> <br />discharge is calculated and compared to the given discharge. Through <br />