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FAQ/ Foundation Formula for House Collapse Zone

Regarding the establishment of a risk zone for house collapse due to flood flow, the following instructions are given in the Flood Assumption Area Map Creation Manual (4th Edition).

Flood Area Mapping Manual (4th Edition) p.23

The basic equation considers the risk of flood flow directly acting on buildings located in the shielding area due to the collapse of the building on the embankment side, and does not consider transmittance and porosity (transmittance and porosity are set to 100%). In addition, an appropriate value shall be set for the bottom roughness coefficient, such as using the values of open space, green space, or road in Table 3.2-1.

Is the house collapse zone calculated by DioVISTA calculated after ignoring the transmittance, porosity, and roughness that the user has set?


DioVISTA uses the [Calculation area] roughness, transmittance, and porosity you set in to calculate the collapse zone.
For the procedure for calculating the porosity to 1, please refer to the FAQ/Manual Procedure for Calculating the Collapse Risk Zone.

Last update: 2023-03-20