Among the development activities that have occurred in Seoul over the past 10 years, buildings have the largest number of buildings. It can be seen that the area of mountainous areas (limnites) is steadily decreasing and is centered on the mountain borders. Development activities are classified into building construction, installation of structures, land form change, land division, and properties of objects, and the permission is decided in consideration of the surrounding environment, harmony, and appropriateness of infrastructure. Although the development activity permit standard contains provisions to prevent disasters such as soil leakage or collapse, detailed standards and specificity are insufficient. Accordingly, it is necessary to prepare specific standards in consideration of disasters at the mountain boundary in the development activity permit standard. Seoul's annual precipitation is expected to increase by 19.9% in the second half of the 21st century based on the SSP5-8.5 scenario, which is expected to increase the likelihood of landslides.
As the Seoul Metropolitan Government's development activity permit operation guidelines lack information on the possibility of disasters caused by development activities, it is proposed to add content to the guidelines to strengthen disaster reduction and safety aspects. In addition, a checklist is established and proposed to review factors that can reduce disasters during development activities. The Seoul mountain borders needs a new technology for four-way projects. Damage reduction technologies applicable to the Seoul Metropolitan Government are divided into the basic work of mountains, green work, slope reinforcement work, and quarterly work, and a construction method suitable for each construction is proposed. In consideration of various other factors, including climate change, it is proposed to improve the criteria for selecting areas vulnerable to landslides and to further strengthen the criteria for mountain area conversion and development activities. In addition, an integrated management system for slope information should be established that is in charge of and managed by each institution to comprehensively grasp the risk of landslides at the mountain borders. When permitting building activities, which account for the highest proportion of development activities, the system should be linked to the recently enacted Forest Disaster Prevention Act to minimize landslides.