On-site conditions of personnel search and rescue in natural disaster scenarios such as debris flows and landslides

A landslide occurred in Junlian County, Yibin City, Sichuan Province. Multiple rescue teams with various professional equipment participated in the rescue, and our company was among them.

Since Since the landslide started at 11:50 am on February 8th, rescue work has been ongoing. As of now, 29 people are still missing, and 2 survivors have been found.

According to an article published by the China Emergency Management News, rescue forces from the People's Armed Police, fire departments, emergency management, public security, transportation, medical, communication, and power sectors were deployed. 900 More than 200 More than excavators, fire trucks, and ambulances, along with drones, radar life detectors, search and rescue dogs, and other search equipment and methods, were deployed for comprehensive, blanket searches.

Our company (Beijing Shengbolan) Since its registration in 2011, has focused on the research and development of life detection technology. This time, we brought radar life detectors, audio-video life detectors, and infrared thermal imaging equipment to assist in the on-site rescue.

I. Difficulties in landslide and debris flow rescue:

Secondary disasters frequently occur at the rescue site, posing significant risks. The high-altitude fault, coupled with continuous rainfall, resulted in continuous landslides after the first large-scale landslide. The rain continued, leading to continuous landslides, soil cracks, soft soil, and traffic obstructions, preventing personnel from approaching in a short time.

The landslide area is large. According to on-site estimates, the landslide area is approximately more than 1.2 kilometers, with a thickness ranging from several meters to tens of meters. The trapped people are buried deep. After the debris flow impact, houses were pushed a long distance away, completely covered without gaps or traces, mixed with rainwater, rocks, and debris, creating a complex environment.

The impact force of the debris flow and landslide is strong. Victims were instantly buried or swept away, with a high risk of suffocation. After oxygen is quickly depleted, the survival window is short, and the probability of survival is low.

II. Needs: However, life is paramount. Regardless of the difficulties, rescuers spare no effort in searching, looking for even a one in ten thousand chance.

Even in environments with a low probability of survival, such as landslides, debris flows, and mine collapses, rescuers still need to search for the remains of the victims.

Beijing Shengbolan, deeply engaged in the rescue industry for 14 years, focusing on the research and production of life detection technology. Currently, the company offers over 30 post-disaster frame inspection and detection devices.

III. How to choose life detection equipment with various technical means currently available on the market? Based on product advantages and disadvantages, principles and technologies, scenarios and forms, our company has made a comprehensive summary and analysis as follows:

According to our incomplete statistics, the currently circulating detection methods are more suitable for implementation in scenarios such as earthquake rescue, building collapses, fire scenes, chemical parks, vehicle detection, mine rescue, and confined space rescue. According to the principle, they are classified as follows:

1. Search and rescue dogs

Scenario: Suitable for post-earthquake debris rescue, building collapses, and outdoor search and rescue.

Advantages: Multi-scenario application, high search and rescue efficiency

Disadvantages: High training costs, rapid physical exhaustion, complex on-site environment, and easy injury.

2. Radar life detector

Principle: It uses ultra-wideband radar technology, using heartbeat and breathing signals as human life parameter characteristics, and identifies life through system algorithms to locate life bodies.

Advantages: Strong penetration ability, can penetrate concrete, cement, gypsum, bricks, tiles, wood, and other obstacles, intelligently judge life bodies, identify static and dynamic targets, display movement trajectories, detect distance, and locate coordinates. It is simple and lightweight.

Disadvantages: Using heartbeat and breathing signals as parameter characteristics, it cannot detect targets that have lost vital signs. Radar characteristics cannot penetrate large areas of metal and substances with high water content.

3. Audio-video life detector (visible light detection equipment)

Principle: Optical imaging technology, converting light signals into electrical signals.

Scenario: Post-earthquake debris rescue, building collapses, confined space rescue, chemical parks, underwater search and rescue, etc.

Advantages: It can collect on-site video, communicate with and comfort trapped people; it can record and broadcast on-site audio. It can perform wireless audio-video transmission.

Disadvantages: It cannot penetrate obstacles; it relies on light reflection and fails in gapless environments. It is affected by cables or illumination, and the detection distance is limited.

4. Acoustic (audio) life detector

Principle: Vibration signals are converted into electrical signals, displayed through bar graphs, and identified by the system. At the same time, noise is filtered, the volume is amplified, and positioning is performed.

Scenario: Post-earthquake debris rescue, building collapses, confined space rescue, chemical parks, vehicles, etc.

Advantages: It can perform active positioning, judging the location of trapped personnel through sound and slight vibrations. It can communicate with and comfort trapped personnel.

Disadvantages: Trapped personnel need to actively make sounds. If personnel are unconscious and cannot actively make sounds, the device cannot fully function.

5. Thermal imaging life detector

Principle: Optical signals are converted into electrical signals, and images are generated based on the infrared light emitted by the human body. After comparison with the environment, the human body outline is formed.

Scenario: Fire scene detection, post-earthquake debris detection, confined space rescue, chemical parks, outdoor search and rescue, etc.

Advantages: Compared with visible light detection, it has a longer detection distance, can penetrate thick smoke, and uses dual-band fusion for clearer images in dark environments. It also has a wide temperature measurement range and is simple and portable.

Disadvantages: It cannot penetrate obstacles, and image clarity decreases when the ambient temperature fluctuates significantly.

6. Personnel Location and Rescue Device

Principle: Based on the combination of a vibration sensor and a timing circuit, a static time is set. If a person falls into a coma, it will automatically issue an alarm and is equipped with a directional light.

Scenario: Fire scenes, chemical parks, and outdoor search and rescue.

Advantages: It can actively send signals.

Disadvantages: It requires pre-deployment and is only for use by rescue personnel. It is not suitable for the search and rescue of ordinary people in temporary earthquake sites. Signal interference and insufficient signal coverage affect communication and positioning accuracy.

7. Gas (Carbon Dioxide) Life Detection Instrument

Principle: It judges the presence of life signs by the change in gas concentration in a confined space.

Scenario: Confined spaces, vehicles, etc.

Advantages: The principle is sound.

Disadvantages: In practical applications, there are few sampling points, and rescue environments are often diffusive scenarios with little change in gas concentration, resulting in insignificant effects.

8. Mobile Phone Signal Detection and Positioning

Principle: Through Bluetooth and WIFI signals, passive positioning is achieved through communication with base stations.

Scenario: Debris rescue, mudslides, landslides, etc.

Advantages: Mobile phone positioning can be performed in a short time to determine the location of personnel.

Disadvantages: It is not a detection performed by the personnel themselves, and there are many uncertain factors. For example, if the phone is thrown out, it cannot be located, and the elderly and children who do not carry the device cannot be located. The phone needs to be turned on WIFI or Bluetooth and other specific functions to be located. Power depletion, damage, or shutdown will affect signal transmission. It requires a high level of expertise and certain professional knowledge and skills.

In summary, fire departments and emergency management bureaus often face urban building collapses and earthquake rescue scenarios. They have effectively implemented numerous rescue missions using radar, audio/video, and thermal imaging, and the technology is relatively mature. Over the years, fire departments and emergency bureaus have effectively implemented numerous rescue missions using life detectors, and the products are relatively mature. For mudslides and landslides, the appropriate solution should be selected based on the specific situation. Please contact our company for details.

                                      Beijing Shengbolan Automation Technology Co., Ltd.   

February 11, 2025