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<br />the encroachment stations selected for any cross section are different <br />frllll the Method 4 cOlllpUter run, it is essential that a final water <br />surface profile be run and evaluated. Method 1 can be used to specify <br />the stations finally selected. <br />EXAMPLE PROBLEM <br />The following is an exa~le of the use of encroachment Method <br />.4 in computer program HEC-2 to develop a designated floodway. Data <br />input has been kept simple to illustrate the techniques. Appendix II <br />shows the input for the problem, an exa~le of the output, and the <br />sUlllllllry printout. A description of the additional computer input <br />necessary for encroachment runs and the additional output are given <br />below. The input and summary printout for a second computer run with <br />selected encroachment stations specified by Method 1 are shown in <br />Appendix III. <br />The input for application of HEC-2 for floodway determination requires <br />only a few cards in addition to thos required for standard applications <br />of the program. The added data necessary to accomplish an encroachment <br />run will be discussed here. Reference should be made to Exhibit 9A of <br />the Users Manual for descriptions of the methods available. <br />Use of the flow distribution option is recommended when computing <br />water surface profiles for floodway determinations. With flow distribution <br />requested, the program prints out the lateral distribution of area, velo- <br />city, and discharge in the overbank areas for each cross section. Because <br />the distribution of discharge is given as a percent, it can also be consider- <br />ed a percentage-distribution of conveyance. The flow distribution information <br /> <br />8 <br />