Jump to content
GMS, SMS, and WMS User Forum

Search the Community

Showing results for tags 'floodplain'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • General
    • News
    • Forum Feedback
  • Arc Hydro Groundwater
    • Using AHGW
  • GMS
    • Using GMS
    • GMS Feature Requests
    • MODFLOW
  • SMS
    • Using SMS
    • Hydraulic Models
    • Wave Modeling
    • Other Models
    • SMS News
    • FHWA - SMS User
  • WMS
    • Using WMS
    • General Hydrology
    • Urban Hydrology
    • Hydraulics and Floodplain Modeling
    • WMS Feature Requests
    • FHWA - WMS User

Calendars

There are no results to display.


Found 1 result

  1. Hello, I am attempting to use WMS / HEC-RAS to determine the threshold discharge for overbank flow in a third-order watershed. This is part of a floodplain sediment storage study. I am running a series of flows through the model and trying to determine the minimum discharge required to initiate overbank flow. I am assessing the overbank threshold visually, using flood depth contours (generated within the _fd dataset). I assume the presence of any flood depth contour ≥0 represents overbank flow in my WMS model (see attached image 1). I also assume that stream reaches without contours present are not exhibiting overbank flow. I should note that I inserted field-measured cross sections into my model. I have three questions: 1.) Can you offer any advice regarding visual (or non-visual) methods of determining the incipient point of overbank flow? I assume if there was a way to indicate top of banks in relation to flow depth, this would be helpful (e.g., a non-planform view of the cross section and associated flood depths). For image 1, the contour range is 0 (min) to 1 (max), with 5 intervals. 2.) The flood depth contour polygons often exhibit a width that is nearly equal to the channel width in my watershed model (Image 1) - so, how can I be sure the flood depth is not being calculated within-channel? Again, I'd like to know if the flood depth is occurring in the floodplain and not in-channel. 3.) I have noticed that many "isolated" flood depth contours appear around cross sections, even at flows that I would not expect to be out of bank. Any thoughts on this? See image 2. Again, I am interested in determining the minimum discharge needed for overbank flow. Any advice on this non-traditional use would be greatly appreciated!!! Thank you.
×