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FAQ/ Flowing Flood Analysis

Is it possible to perform downflow type flood analysis for small and medium-sized rivers? Guidance for creating a map of small and medium-sized rivers inundation assumption area June 17) is assumed to be analyzed in accordance with the following requirements.

Guide to creating a map of inundation areas for small and medium-sized rivers, June 17, p. 13

In categorization, if it can be evaluated as a flowing type flood, it is treated as a flowing type flood.


I can.

It can be analyzed as an unequal flow or an irregular flow. The distribution of inundation level and inundation depth is calculated over time.

Functional limitations

When output in MLIT NetCDF/CSV format, the flow rate becomes 0. This is because the function of DioVISTA's flowing flood analysis is that only the water level obtained by 1D irregular flow analysis is expanded into a 2D mesh, and the flow velocity is not expanded to the 2D mesh.

In the guide for creating a map of the inundation area of small and medium-sized rivers, June 17, p. 26, the flow velocity is listed as data that should be organized and stored in the case of downflow type flood calculation. This flow velocity is always 0.


In the Guide for Creating Maps of Small and Medium-sized River Flood Inundation Prediction Areas (2nd Edition) March 28, the following requests are made.

Guide to Drawing Flood Inundation Areas for Small and Medium-sized Rivers (2nd Edition) March 28, p. 1

In the past, it took time to analyze two-dimensional planar flow when studying manually, but in view of the dramatic reduction in calculation time due to the improvement of computer power in recent years, it is recommended to conduct studies in accordance with the manual.

The "manual" here refers to the Flood Prediction Area Map Creation Manual (4th Edition).

We also recommend that you use the analysis function in accordance with the Flood Area Mapping Manual (4th Edition).

Figure: Example of flowing flooding using one-dimensional unequal flow by DioVISTA


FAQ/ Isoflow Calculation

Last update: 2023-03-17