How to Respond to Flash Floods and Carry Out Rescue Operations?

Introduction

 

On May 23, 2025, at around 3: 00 a. m. , a flash flood and mudslide hit Sishui Township, San She Village, Longsheng County, Guilin, Guangxi, due to heavy rain. According to Xinhua News Agency, 8 people went missing, 3 were injured, and 10 houses were destroyed. Roads, power lines, and communication networks were also severely damaged. Local authorities quickly launched an emergency plan. Firefighters, armed police, and Blue Sky Rescue teams joined the search and rescue efforts.

 

Flash floods are one of the most dangerous natural disasters. They come fast, flow rapidly, and carry strong force, often leading to massive damage. Guangxi, with its mountainous terrain and frequent rainfall, is a high-risk area for flash floods. This article takes the Longsheng event as an example to explain what flash floods are, how to respond, and how rescue teams use modern equipment to reduce risks and save lives.

What Is a Flash Flood?

A flash flood is a rapid and powerful flood caused by heavy rain, melting snow, or dam failure. It usually occurs in mountainous or hilly areas. Due to steep slopes, water collects and rushes down quickly.

Common Causes:

Heavy rainfall: Sudden, strong storms bring huge amounts of water in a short time.

Terrain: Steep and uneven land speeds up water flow.

Saturated soil: After continuous rain, soil cannot absorb more water, leading to surface runoff.

Human activities: Deforestation and construction can damage natural drainage systems.

Blocked rivers: Landslides or debris can block rivers, forming dangerous temporary lakes.

Key Features of Flash Floods:

Sudden onset: They happen quickly with little warning.

Local impact: Damage is often limited to specific valleys or small regions.

Strong destruction: They can cause mudslides, building collapse, and casualties.

Hard to predict: Traditional methods struggle to give early and accurate alerts.

 How to Respond When a Flash Flood Strikes

 

 Early Warning Signs

Before a flash flood or mudslide, there are usually warning signs:

1.Rainfall continues for hours, and river levels rise fast.

2.Strange sounds from hillsides, visible cracks on the ground.

3.River water becomes muddy and carries debris.

4.Houses show signs of leaning or cracks.

5.Animals act strangely, such as fleeing together.

To improve response time, professional monitoring systems are also needed.

LSJ HXSAR-5KS Slope Stability Radar

The HXSAR-5KS is a high-tech radar system designed to monitor landslides and other geological disasters. It uses Synthetic Aperture Radar (SAR) and Differential Interferometry (DInSAR) to provide accurate and real-time warnings.

 

Key Features:

1.All-weather operation: Works in rain, fog, and darkness.

2.High precision: Detects small movements and cracks.

3.Real-time data: Sends data remotely for quick decision-making.

4.Wide coverage: Can monitor multiple locations from one position.

5.Long range: Covers up to 5 km, ideal for large mountains.

This LSJ HXSAR-5KS Slope Stability Radar

 helps rescue teams assess risks and plan safe evacuation routes.

Emergency Actions

If a flash flood strikes:

1. Move to higher ground fast. Avoid rivers, hillsides, and low areas.

2. Do not walk or drive through flooded roads.

3. If inside a building, cut off electricity and prepare to evacuate.

4. Bring an emergency kit: food, water, flashlight, rope, phone.

5. Children and elderly people should be accompanied.

 

Rescue Operations During Flash Floods

 

Rescue Priorities

The first 72 hours after a disaster are critical. Rescue teams must:

• Search for trapped or missing people first.
• Help the vulnerable groups like children, elderly, and injured.
•  Identify dangerous areas to avoid new disasters during rescue.

 

Rescue Equipment

 

Monitoring Equipment:

Slope stability radar: Tracks unstable hillsides.

Weather meters: Measure rainfall, wind, and temperature.

AC voltage detectors: Check safety before entering flooded zones.

Search and Rescue Devices:

Array seismic life detectors: Listens for sounds from trapped victims like scratching, knocks, shouts.

Radar life detectors: Uses UWB technology to locate buried survivors.

Search and rescue cameras: Help rescue teams see trapped people and talk to them.

Drones: Used for aerial survey, dropping life rings, and guiding rescue.

Two-way radios: Ensure clear team communication.

Inflatable boats: Help move people out from flooded villages or valleys.

Post-Rescue Tools:

Water pumps, emergency power generators, disinfection machines, and tents.

Teamwork and Coordination

 

Rescue success depends on good organization:

Government leads: Emergency teams follow a unified command.

Cross-department support: Firefighters

police, medical teams, utility providers work together.

Digital command system: Tracks progress and updates rescue plans in real-time.

Post-Flood Recovery and Safety

 

Preventing Secondary Disasters

1.Continue to monitor landslides, dam failure, and road collapses.

2.Clear blocked roads and repair power and water systems.

3.Limit access to dangerous areas.

 

Health and Disease Control

1.Disinfect flooded homes and streets.

2.Ensure clean drinking water to avoid diseases.

3.Build temporary toilets and garbage collection areas.

 

Mental Support and Community Rebuilding

1.Send counselors to visit affected homes.

2.Pay attention to children and elderly people's mental health.

3.Offer financial aid and support reconstruction.

4.Promote disaster knowledge and run drills regularly.

 

Lessons Learned from Longsheng Flash Flood

 

The Guangxi Longsheng disaster showed that many mountain villages still lack strong warning systems. Some local people do not know how to respond to floods, and rescue equipment is not evenly distributed.

 

We need to improve in these areas:

Better warning systems: Use slope radar, rainfall data, and public alerts.

Public education: Teach people how to escape and respond to disasters.

More advanced equipment: Promote use of radar life detectors and drones.

Stronger teamwork: Build fast-response rescue systems involving all departments.

 

Flash floods are dangerous, but they are not beyond control. With strong early warning systems, public awareness, proper equipment, and teamwork, we can reduce the damage and save more lives.

As extreme weather events become more common, flash floods and landslides are happening more often in mountain areas. Slope stability radar is now an important part of disaster prevention.

The LSJ HXSAR-5KS radar system is already used in many regions. It provides 24/7 high-precision monitoring across wide areas. It helps authorities and rescue teams detect early signs of danger and take action in time.

If you work in fire service, emergency management, civil defense, USAR rescue teams, disaster monitoring, please contact us for custom rescue equipment and solutions.