floodlab2019@co-risk.org

Field Work with OASIS Lab in Mae Chan – Flash-Flood Early Warning

Written by David Lallemant

Field Lab participants went with the OASIS Lab of Chiang Mai University to Mae Chan community near Thai-Burmese border to explore the possibilities of installing a new flood sensor prototype developed in the previous week. The OASIS lab has worked with the Mae Chan community for many years, as it regularly suffers from flash floods. They have installed a flood-sensor upstream and designed web-based platform to inform community leaders and the public of imminent floods.

– Visit and feasibility-testing of the new flood-sensor + optical picture trigger prototype
– Meeting with local government risk management officer
– Collected drone photogrammetry photage of flood-exposed areas
– Collected 360 degree camera photage of flood-exposed areas
– Interviewed residence having experienced floods
– Interview with manager of the weir / flood alleviation system

Upon arrival the group met with the local government disaster risk management officer to better understand the flood issues of Mae Chan, and learn more about the unique collaboration they have formed with the OASYS Lab.

We later visited the current site for the upstream flood-sensor, and did a feasibility test for the improved sensor (below). The new system addresses the challenge of false-positive alarms and need for confirmatory evidence of imminent flooding, which is achieved by adding a camera to the existing system. Since cameras use a lot of power, we proposed a triggering system to only turn on the camera if the water level gets above a certain threshold based on the ultra-sonic sensor. The system must be installed on a bridge, with camera view of the flood-water and the analogue river gage. This is what we were testing.

Later, the government disaster management officer offered us to set up camp at the Mae Chan fire station (above & below). From there we launched a drone imagery survey, based on a predetermined flight path along the areas most exposed to flooding. We collected 360 imagery using a sensor mounted to a motorcycle helmet. These data can be used to develop detailed exposure models for understanding flood risk.

Other participants interviewed residence who had experienced flooding. Residence generously shared their time and stories, and showed us evidence of large floods still visible as discoloration on the walls of their homes.

The next day we met with the manager of the local weir (right). In times of flooding, it is his role to open the weir to divert the flood waters to side canals and rice fields. He has been doing this for over 30 years.


This marked the end of our field work. We hope to continue working with the OASIS lab to implement the sensor system in Mae Chan and other communities.