HEC-RAS field data collection
HEC-RAS field data collection
(OP)
Does anyone know of a good set of instructions to provide surveyors collecting HEC-RAS field data? Our surveyors have not collected field data for HEC-RAS model input before. I'm sure I could let them know what's needed but perhaps someone out there has already gone through this. I'm not being lazy mind you, I just have limited HEC-RAS experience so I want to ensure I'm considering everything.
Thanks,
DLN
Thanks,
DLN





RE: HEC-RAS field data collection
RE: HEC-RAS field data collection
By the way, thanks for the quick reply.
-DLN
RE: HEC-RAS field data collection
RE: HEC-RAS field data collection
As cvg mentions, you do need the structures to be picked up, and depending on budget and your tolerance for error, a detailed survey of the bank/channel, though again, especially with possible debris in the channel, the fraction of water flowing in the channel during a flood is small and "holes" in the channel, though contributing some turbulence, are ineffective flow areas, and not necessarily worth the time and effort of survey.
I suggest that you use the 5' topo to select your cross-section locations so that your field survey crew has an idea where to go; cross-sections should not be straight lines, but rather perpendicular to the flow direction. What do you do when HEC-RAS gives you an error indicating that more x-sections are needed? Do you send the crew out again or interpolate x-sections? If the latter, wouldn't a 2' or 1' flown topo be more accurate?