In this post, I'll tell you how to construct a 2D Unsteady Flow Analysis using HEC-RAS. In most of water-related projects, hydraulic analysis is essential to assess an existing water system and further to propose mitigation measures if necessary.
Before we start with the tutorial, knowing why we need to have a 2D model is important. There are some reasons why a 2D model is needed. First, if you want to know the flood extent of your interest area then certainly you need a 2D model. Second, if your study area has large flood plain areas it is a sign that you need a 2D model. In many projects anyway, 2D modelling is required. So, lets start with what data are needed:
a 2D hydraulic model needs inflow hydraulic in the upstream boundary condition. The inflow hydrographs can be a streamflow record of flood event or design inflow hydrographs. For design inflow hydrographs, it can be used HEC-HMS software (Separated Post will discuss about this).
The example of inflow hydrograph is shown below:
As you can see, the inflow hydrograph show the time series of flow in m3/s during flood event.a 2D hydraulic model needs inflow hydraulic in the upstream boundary condition. The inflow hydrographs can be a streamflow record of flood event or design inflow hydrographs. For design inflow hydrographs, it can be used HEC-HMS software (Separated Post will discuss about this).
The example of inflow hydrograph is shown below:
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| Inflow Hydrograph |
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