Debris Flow and Large-Scale Landslide Disaster Prevention Information Network

Typhoon Morakot caused a large-scale landslide disaster, initiating subsequent investigations and disaster prevention planning.

• The Executive Yuan convened an inter-ministerial meeting to establish the division of responsibilities for hillslope landslide disaster prevention, which was subsequently recorded by the Central Disaster Response and Command Center.
• It was resolved that the investigation, analysis, and promotion of large-scale landslide disaster potential would be discussed and coordinated by the National Science and Technology Council (NSTC) and the National Science and Technology Center for Disaster Reduction (NCDR), in conjunction with relevant agencies.

• The Central Geological Survey (CGS) reported the survey results for the southern region of the Morakot disaster area to the Central Disaster Response and Command Center.
• The Executive Yuan's Disaster Management Office organized a visit program to inspect communities with potential large-scale landslide risks within the Morakot reconstruction areas.
• The CGS subsequently reported the survey results for the central and eastern regions of the Morakot disaster area to the Central Disaster Response and Command Center.
• The Soil and Water Conservation Bureau (SWCB) of the Council of Agriculture (COA) established the "Expert Advisory Committee for Hillslope Landslide Mitigation and Disaster Reduction" and convened multiple meetings to finalize the framework for medium-to-long-term plans, alert factors, and rainfall analysis methods.

• Thirty-six large-scale landslide potential areas were made public.
• Working consultative meetings were held to develop the procedures, methods, on-site mapping, and verification processes for delineating the impact areas of large-scale landslides.
• Through the expert advisory committee, short, medium, and long-term plans were formulated, the division of labor among various agencies was established, along with the definition and public disclosure methods for potential areas, and the procedure for issuing alerts.
• The Council of Agriculture (COA) of the Executive Yuan submitted the "Large-Scale Landslide Mitigation and Disaster Reduction Program under Climate Change (2018-2021)" to the Executive Yuan for approval.
• Discussions were held during the expert advisory meetings regarding the refinement of the response mechanism and monitoring methods. It was determined that **surface displacement** would be the initial basis for issuing alerts, with a comprehensive consideration of factors like **groundwater level** or **subsurface displacement** to be added in the long term.

The response procedures for different types of large-scale landslide potential areas were established and integrated with the alert mechanism for debris flow. The number of program implementation areas increased to 238.

• Twelve large-scale landslide potential areas were made public.
• The Executive Yuan approved the implementation of the large-scale landslide alert issuance operation.
• An expert meeting was convened to discuss the emergency response for the Guanghua potential area.
• The areas prioritized for management and monitoring were expanded, with the number of program implementation areas increasing to 269.

• Thirty-six large-scale landslide potential areas were made public.
• The Disaster Prevention and Protection Act was amended, revising "debris flow disasters" to "debris flow and large-scale landslide disasters." Large-scale landslide disasters were formally included as a statutory disaster category.
• A unified alert issuance mechanism was established for typhoons and torrential rain periods, along with a mechanism for lowering the alert rainfall threshold following earthquakes.
• The number of alert issuance areas increased to 48 in 2023 (Year 112), and the number of program implementation areas increased to 306.

• Forty-eight large-scale landslide potential areas were made public.
• The Council of Agriculture (COA) was upgraded to the Ministry of Agriculture (MOA), and the Soil and Water Conservation Bureau (SWCB) was reorganized as the Agency of Rural Development and Soil and Water Conservation (ARDSWC).
• The "Operating Procedures and Methods for Delineating the Impact Area of Large-Scale Landslide Potential Areas" were released to the public.
• Review and working group meetings were convened to examine the year's disaster records, alert thresholds, and newly added potential areas, increasing the number of program implementation areas to 315.

Sixty-five large-scale landslide potential areas were made public. Working group and review meetings were convened to discuss and examine the impact areas and alert types for potential areas slated for public release that year, as well as the addition of new potential areas and alert thresholds for the following year.

A Monitoring and Readiness Working Group meeting is scheduled to be held to continuously review and adjust the management values and alert thresholds for monitoring instruments, and to plan for the public release of hillslope emergency assessment results. There are plans to expand the priority management and alert issuance areas. The number of alert issuance areas is projected to increase to 96 in 2026 (Year 115), with program implementation areas increasing to 327.