Devastation Beyond Comprehension Can it be prevented, if so how?

It's hard to put into words the devastation created by the January 9, 2018, mudslide disaster that took place shortly after the widespread fire that destroyed hundreds and hundreds of acres. It seems the perfect storm brewing that created this disaster as all the vegetation had been thoroughly stripped from the wildfires. And then came an unusual weather pattern that that dropped large amounts of rain on the surrounding community of Santa Barbara.

Normally such amounts of rain would've only produced large amounts of runoff perhaps encompassing some debris. However, because the fire stripped all the vegetation this was a recipe for disaster as just beneath the soil was a layer that is created after such intense fires that does not allow the water to be absorbed into the ground. Therefore every drop of water for the most part that hits the surrounding area will drain off to the natural Canyon areas in this particular instance created a debris slide that included all the burnt ash, and as that rolled down the canyons picked up boulders the size of vehicles and small houses and removed large trees as well!

Anything that was caught in the path of this debris slide was devastated including entire homes removed off the foundations and if the residents did not have time to evacuate, many of those sadly lost their lives. The havoc of this event downstream of this disaster is is truly hard to imagine the size and scope of the disaster but I think the pictures that follow provide a good indication of just how devastating this event was.

This video (no sound) covers some of the areas around Randell Road and shows the devastation brought upon this community as a result of the wildfires and the subsequent rainfall. To date, this community Is still dealing with the cleanup as well as planning and putting in place ways to help mitigate another disaster like this one.

In September Airborne Works had the privilege of being invited to teach a workshop at InterDrone 2019 on mapping utilizing UAV/UAS technology as well as innovative integration ground-based of terrestrial lidar to provide detailed surface models and maps. At that workshop in the audience was a partner of ours Mr. Harry Rabin, Harry has a rather distinguished career and is a well-known cinematographer for his work for such organizations as, National Geographic and Discovery channel to name a few. Harry also happens to be a long-time resident of Santa Barbara and an active individual in the community and directly connected to the environmental protection efforts of both land and sea. After the workshop, we got to discussing about the disaster that took place in his hometown community and how they are working to study and monitor the area and find ways to mitigate similar events. That conversation allowed Harry and I to realize that we may be able to help with this effort and prompted a conference call with community leaders directly involved with building a solution within the six canyons above this community.

Since the time of the disaster FEMA and other government agencies have contributed large sums of money to help clean up and also implement solutions to mitigate the same type of disaster but also to discover new ways to monitor the conditions of the ground within the riverbeds that run through the canyons. One of the solutions that are being installed is ring-fences as shown in this picture. These fences are installed so that large objects including boulders and trees Will be hung up and prevented from going further down the canyon. Another method to catch large debris that pass through or around the ring-fences will be to construct large man-made catch basins placed at the bottom of the canyon so that all large degrees that flow will have a chance to slow down and deposit larger objects within the catch basins and allow the more fluid lighter weight materials to pass.

Because Airborne Works understands the technology and the level of detail that can be captured utilizing ground-based terrestrial lidar in conjunction with ariel photogrammetry, after a number of emails and conversations we offered at no charge to the community leaders for us to go into the Randall Road area that was affected by this disaster, also an area of interest to the geologist. There we could utilize ground-based terrestrial lidar to demo scan an area of interest along the riverbed next to a bridge that survived the mudslide. (as noted in image above) This area is one of the areas already identified for the construction of a large catch basin. We wanted to show the geologist, investors and FEMA the level of detail that can be captured utilizing this type of technology. Because we can integrate this Lidar data with UAV/UAS aerial photogrammetry it proves a very powerful tool to provide topography that can meet survey grade standards. We are also able to produce large data sets very quickly and accurately saving time and money. This will be a useful tool for the geologist tasked with monitoring the surrounding changes in areas over time. The advantage of ariel photogrammetry is clear however it does present some limitations as the canopy of foliage does not allow the geologist to get a good reference of the topography below the foliage. The combination of UAV/UAS aerial photogrammetry and ground-based terrestrial lidar provides very actionable data for the geologist and scientist looking to better understand how to prevent and study these types of disasters.

Airborne Works is no stranger to large projects, In October of 2019 Airborne Works received a contract from a non-profit environmental group, the Barnstable clean water coalition, we were tasked with providing the mapping of a large Island on Cape Cod, This Mapping was the first of its kind in Cape Cod history using UAV/ UAS technology. We also scanned about 600' of beach with Lidar on the western end. This video will give you an idea of the size and scope of the project, our client requested that the model is geo-spatially correct, Part of the deliverables would be 12" contours and digital terrain in digital service models, we also provided overlay Lidar from GIS data captured after 2012 storm Sandy that ripped through this area.

The group that attended the scanning demonstration were thoroughly impressed with the results of the scans. The data Harry and I collected allowed us to demonstrated the use case of this technology for detecting and monitoring the topography's of large areas that are important to the geologist, we took a total of five scans as proof of concept.

Please note within the report below out of a total of five scans we had a total error 7/16 of an inch! We did not even take a lot of time to link all the registrations of the scans together. We did use some targets and the Leica software auto-registered four out of the five scans. This speaks to the accuracy and speed that can be obtained utilizing ground-based terrestrial lidar and when you combine this with photogrammetry with accurate survey placed ground control points the data will be very useful in many types of situations.

If you would like to learn more about what we're doing to utilize this technology to help the scientist and geologist better understand how to protect their communities, please follow our post. Also if you'd like to see the actual data set we could send you an LGS file with a link to jetStream viewer, this is free software that will allow us to share any of the data from our demos for our clients. Please feel free to contact me directly with any questions or if you have a project that you think this technology might be a valuable and helping to identify in better understand pain points within your projects.

Stay tuned for more information on this project in the very innovative use of ground-based terrestrial lidar combined with aerial photogrammetry as it becomes available. Contact us at [email protected]