This paper is the result of geological hazard survey engineering.
Objective Gansu Province is among the regions in China with a high incidence of geological hazards. The scientific establishment of the "point−surface dual control" mode for geological hazard risks is crucial for hazard prevention and mitigation.
Method Taking Longlin Town as an example, this paper presents the technical process for managing and controlling geological hazard risks in typical urban areas based ondetailed on−site refined survey and mapping, multi−phase remote sensing data modelling, laboratory test, and numerical simulation analysis. The process includes six steps: geological hazard risk identification, disaster mode research, risk analysis, vulnerability assessment, risk assessment, risk prevention and control countermeasures. Additionally, it introduces the semi−quantitative risk assessment process of urban risk slope. A quantitative risk assessment method for single geological hazard based on dynamic process, as well as the "point−surface dual control" mode for geological hazard risk have also been established.
Results (1) The primarygeological hazards identified in the study area are landslide and debris flows, with a total of 71 hidden hazard points, 15 of which pose direct threats topublic safety and property. Three landslide hazard modes are summarized, and geological early identification signs are established. (2) Risk zoning based ondifferent precipitation frequencies (5%, 2%, 1%) reveals that 75.23% of the regions consistently maintain low risk levels, 24.38% exhibit increased risk levelsas precipitation frequency decreases, and 0.39% remain in high risk levels. (3) Based on the risk assessment results, a comprehensive dual control strategy for hazard risk reduction in towns and specific disaster hazardsis proposed.
Conclusions This research provides technical support for hazard prevention and mitigation, as well as for land use planning and management in complex mountain towns.
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