Rain induced debris flows can cause serious damage to structures and loss of human life. It is important to have high rain induced debris flow risk zones identified so that land use planning and early warnings can be put in place.
The algorithm used in japan to identify these high risk areas can be applied globally, as long as there is a relatively high-resolution DEM (in TIN format, ideally I:2500). (The algorithm is mainly based on slope angle). The task is to develop an app that can take the TIN of a hilly, mountenous area and apply the algorithm, and make the output useful for land use planning or for early warning. Additional functions may be considered.
Early warning systems for rain induced debris flows is beyond the scope of this project. however. if interested, please refer to http://www.typhooncommittee.org/45th/Docs/item%2011/MHSD_FINAL.pdf pages 6-10. For the rain induced debris flow high risk zone identification, please refer to pages 20-24 of the same document.
Once the app is developed, it can be used globally to identify high-risk areas from rain induced debris flows, given an appropriate DEM TIN is available for the purpose. Technical assistance is available, please contact the Code for Resilience team. This app will help disaster management agencies and land use planning agencies to consider evacuation plans for people living in these high risk areas, as well as consider putting in place restrictions in the structures that can be built. If an app that can warn people in advance can be developed, it will save lives.
The caveat is that the algorithm is not 100% perfect (it will miss some high risk areas, particularly depending on the granularity of the DEM/TIN), but it is very useful to identify the high risk areas to put emergency proceedures in place.