What are the differences in OpenFlows FLOOD and HEC-RAS®?
HEC-RAS or “Hydrologic Engineering Center's River Analysis System”; is a software developed by US Army Corps of Engineers. This software helps the user to perform one-dimensional (1D) steady flow analysis, one and two-dimensional unsteady flow calculations analysis, sediment transport/mobile bed computations and water temperature/water quality modeling.
OpenFlows FLOOD on the other hand, is a single tool to implement an integrated modeling solution capable of imposing spatially and temporally varying rainfall (using direct rain-on-grid). With this you can impose rainfall from a constant value, or from one or more time-series (hydrographs) or from a meteorological model. Once the rainfall hits the surface, rainfall water is converted in 2D overland flow (based in topography), and FLOOD can estimate losses by infiltration and evapotranspiration (both variable in space and time). The infiltration / flow through porous media (saturated and unsaturated) to the ground can also be modeled (in 3D) with variable layer thickness. There is also interaction with the (1D) drainage network through rivers and canals.
Water moves through all the mediums (atmosphere, porous media, soil surface, and river network) based on mass and momentum conservation equations. The interactions between the different processes (like water exchange between aquifer and river) are calculated dynamically by the model, using the hydraulic gradients. MOHID Land can model the whole system described above, however the 1D surface drainage network can also be modeled using SewerGEMS (SWMM engine), with the advantage of this solver including a wide panoply of hydraulic structures (including culverts, etc.), among other features and capabilities.
If stormwater drainage network exists, OpenFlows FLOOD can also integrate this subsurface network, dynamically interacting with both 2D surface runoff and (1D) surface drainage network system. Bidirectional interaction between surface runoff and stormwater drainage network is done through manholes or inlets / storm drains. For more information on this, see here.
FLOOD can also be used for modeling coastal flooding, including storm surges and tsunamis and for modeling water quality (nutrient cycles) and water contamination (microbiology or other contaminants) and sediments transport.
Differences in OpenFlows FLOOD and HEC-RAS
Some of the major main differences in terms of features between OpenFlows FLOOD and HEC-RAS are as follows;
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