Download Rioni_river_Practica..
Transcript
HEC RAS analysis Input 9/27 MATRA Project ITC WRS: Gabriel N. Parodi Figure 13: Final distances between the cross sections for the LowerPoti reach. Figure 12: Final distances between the cross sections for the Upper reach. Figure 14: Final distances between the cross sections for the LowerLeft reach. Figure 15: Final distances between the cross sections for the LowerRight reach. Figure 16: Final distances between the cross sections for the Lower reach. Left and right banks The next step is the establishment of the left and right banks (LB and RB). By default HECRAS assumes that the first and last station of each XS is the LB and RB respectively. This must be corrected in order to assign the correct roughness. Keep in mind that the channel is not the area where the water was flowing in the survey, but the area where the water could flow without producing a flooding to the overbanks. During the XS survey, the surveyor should make specific notes on which is the beginning and end of the channel and the overbanks. In this way the process of informing this to HECRAS is easier an accurate. Photo 1 gives some guidelines on channel determination and roughness. Page 9 of 27