Here are the levels of disaster risk due to flash floods, landslides, and ground subsidence caused by heavy rainfall or flowing water.
1. Levels of Disaster Risk Due to Flash Floods, Landslides, and Ground Subsidence
According to Article 46 of Decision 18/2021/QĐ-TTg, the levels of disaster risk due to flash floods, landslides, and ground subsidence caused by heavy rain or flowing water are defined as follows:
Disaster risk level 1 includes the following cases:
- A total rainfall warning of 100 mm to 200 mm within 24 hours and rain that occurred 1 to 2 days prior in areas with low or medium risk in provinces of region 1; medium risk areas in region 2; high-risk areas in region 3; and very high-risk areas in region 4;
- A total rainfall warning of over 200 mm to 400 mm within 24 hours and rain that occurred more than 2 days prior in low-risk areas in provinces of region 1 and region 2; medium-risk areas in region 3; high-risk areas in region 4;
- A total rainfall warning of over 400 mm within 24 hours and rain that occurred more than 2 days prior in low-risk areas in provinces of region 3; and medium-risk areas in region 4.
Disaster risk level 2 includes the following cases:
- A total rainfall warning of 100 mm to 200 mm within 24 hours and rain that occurred 1 to 2 days prior in high-risk areas in provinces of region 1 and region 2; very high-risk areas in region 3;
- A total rainfall warning of over 200 mm to 400 mm within 24 hours and rain that occurred more than 2 days prior in medium-risk areas in provinces of region 1 and region 2; high-risk areas in region 3; very high-risk areas in region 4;
- A total rainfall warning of over 400 mm within 24 hours and rain that occurred more than 2 days prior in low or medium-risk areas in provinces of region 1 and region 2; medium or high-risk areas in region 3; high or very high-risk areas in region 4.
Disaster risk level 3 includes the following cases:
- A total rainfall warning of 100 mm to 200 mm within 24 hours and rain that occurred 1 to 2 days prior in very high-risk areas in provinces of region 1 and region 2;
- A total rainfall warning of over 200 mm to 400 mm within 24 hours and rain that occurred more than 2 days prior in high or very high-risk areas in provinces of region 1 and region 2; very high-risk areas in region 3;
- A total rainfall warning of over 400 mm within 24 hours and rain that occurred more than 2 days prior in high or very high-risk areas in provinces of region 1 and region 2; very high-risk areas in region 3.
If the warning area contains multiple regions with different levels of disaster risk, the highest level of risk will be taken into account.
Severe landslides affecting local residents.
The list of provinces in regions 1, 2, 3, and 4 is specified in Table 5 of Appendix XII of Decision 18/2021/QĐ-TTg:
- Region 1: Lai Châu, Sơn La, Điện Biên, Hòa Bình, Lào Cai, Yên Bái, Hà Giang.
- Region 2: Tuyên Quang, Bắc Kạn, Lạng Sơn, Cao Bằng, Thanh Hóa, Nghệ An, Quảng Ngãi.
- Region 3: Phú Thọ, Thái Nguyên, Quảng Ninh, Hà Tĩnh, Quảng Bình, Quảng Trị, Thừa Thiên Huế, Da Nang City, Quảng Nam, Khánh Hòa, Kon Tum, Gia Lai, Đắk Lắk, Đắk Nông, Lâm Đồng.
- Region 4: Vĩnh Phúc, Bắc Giang, Hải Phòng, Bình Định, Phú Yên, Khánh Hòa, Ninh Thuận, Bình Thuận.
2. Content of Flash Flood, Landslide, and Ground Subsidence Warning Messages
The content of flash flood, landslide, and ground subsidence warning messages according to Clause 6, Article 15 of Decision 18/2021/QĐ-TTg includes:
- The title of the flash flood, landslide, and ground subsidence warning including the name of the area and location of the report;
- The rainfall situation in the watershed over the past 6 hours;
- A warning of expected rainfall in the following period;
- A warning of areas at risk of flash floods, landslides, and ground subsidence due to heavy rain or flowing water (if any);
- A warning of the level of disaster risk due to flash floods and landslides as regulated in Articles 4 and 46 of Decision 18/2021/QĐ-TTg;
- The time of issuance of the bulletin;
- The name and signature of the person responsible for issuing the bulletin.
Another pattern causing heavy rain in Northern Vietnam
