While the fires were still spreading in Los Angeles, investigators were busy exploring possible reasons for the fires and looking for indicators that could have provided more advanced warnings. Sensors always play an essential role in any advanced or real-time warning system. The more obvious sensor requirements/possibilities for wildfires include:
- Wind direction and speed
- Water reservoirs’ level
- Water hydrants’ pressures and flow rates
Unlike normal conditions, current weather patterns in the Pacific Ocean have created a La Niña event, which has the opposite effect of an El Niño event. Both typically last nine to 12 months.
In La Niña events, Santa Ana winds can easily occur. These winds result when air from a region of high pressure over the dry, desert region of the southwest flows westward towards the low-pressure region located off the California coast. The dry winds that flow through the mountain passages in Southern California increase wildfire risk because of their dryness and the speed at which they can spread a flame across the landscape. When Santa Ana winds blow through canyons, like east of Los Angeles, Bernoulli’s Principle and the Venturi effect increase the wind speed. In the recent fire, wind gusts reached up to 99 mph or more.
Both contact and non-contact sensors can measure the water level in reservoirs. In addition to cameras for non-contact remote water-level viewing, another technique commonly used in water-level measuring instruments utilizes radar technology. Since the water level in a reservoir changes more slowly than in other water bodies, this stability allows the radar water-level meter to measure the water level accurately and provide timely feedback to management personnel.
The National Fire Protection Association (NFPA) NFPA 291 Standard requires fire hydrant flow testing every 5 years and performing fire hydrant inspections annually. In addition, the internationally recognized Joiff Standard provides guidelines for flow and pressure testing of fire hydrants to ensure sufficient water capacity is available for firefighting.
Ting sensor
One not-so-obvious sensor for fire warnings identified early in the investigation was Whisker Labs’ Ting sensor. The patented sensor detects faults generated by electrical arcs. Plugged into any home’s standard single-phase, 120-V outlet, the Ting sensor uses a Wi-Fi connection to communicate with the Ting servers. The sensor detects the low-level electromagnetic emissions associated with micro-arcing characteristics of potential electrical faults that generate very high frequencies. At these frequencies, home wiring provides a communications network for the signal. Using post-processing algorithms, the Ting sensing system separates the signal from the noise and detects if there is unusual electrical activity.
Since dangerous arcing is the precursor to most electrical fires, State Farm Insurance has collaborated with Whisker Labs to provide free Ting sensors nationwide for eligible customers. With a network of around 14,000 sensors located in homes across Los Angeles, Whisker Labs was able to monitor the electric utility grid. Specifically in the Palisades area, 63 faults were identified two to three hours before the fire ignition. Also, 18 faults registered within the hour the fire began.
These are just a few sensing techniques for those preparing for wildfire seasons. They should be considered in their fire management and control measures.
References
What are El Niño and La Niña?
National Weather Service: Mountain and Valley Winds
Power grid faults surged right before Los Angeles wildfires began: expert | Fox News
Whisker Labs
Patents – Whisker Labs
Ting Smart Sensor | DIY Home Improvement Forum
State Farm® expands Ting fire safety program to 2 million homes
Filed Under: Sensor Tips