Laserfiche WebLink
<br />Dill Colllcllon & Anllyals . <br /> <br />e <br /> <br />~: <br />o Velocity... <br />DWaler Depth... <br />o Maxilnlm Discharge and Water Depth... <br />o Historical Data... <br />o Problems Upstream.. <br />o Problems Downstream... <br /> <br />o Types of Flows Experienced... <br /> <br />5,3 Data Collection & Analysis - <br /> <br />This section presents a discussion of the data which should be collected and analyzed to <br />help formulate an understanding of the conditions associated with an eroding banldine. <br />Table 5-6 provides a summary of potential sources for the data at the end of this section. <br /> <br />5,3,1 Survey and Maps . <br /> <br />River engineering typically requires some surveying and mapping, particularly where <br />detailed analysis or design is needed. Map scale varies with detail needed for layout of <br />structures. In steep terrain, scales of 1 in. = 400 ft. to 1 in. = 100 ft. with contour <br />intervals of 10, 5, or 2 ft. are appropriate. In flat terrain I-fl. contours are usually <br />needed (peterson, 1986) <br /> <br />A permanent second-order horizontal control line (base line) is usually established <br />throughout the study area along one bank and above the water surface for use in layout <br />and construction and as a reference for periodic resurvey of channel cross-sections. The <br />line should be monumentcd, and elevations of the monuments established. (Peterson, <br />1986) <br /> <br />For major channel rectification and stabilization work, permanent ranges across the <br />river are usually needed at a minimum of IlXlO-fl intervals. Such ranges are tied to the <br />horizontal base line. Profiles across all of the ranges, or selected ranges, are needed <br />intermittently through the stody period, during construction, and for operation and <br />maintenance after completion of construction. (Peterson, 1986) <br /> <br />e <br /> <br />Information on characteristics (shape, width, depth) of river reaches that are relatively <br />stable in their natural condition can be helpful if it may be assumed that similar cross <br />sections achieved with man-made stmctures (dikes and revetments) will also tend to be <br />stable. (peterson, 1986) <br /> <br />Colorado Erosion Control Manual <br /> <br />!iT <br />