The Nan Provincial Office of Natural Resources and Environment (ONRE Nan), together with geological experts, inspected ongoing land subsidence and ground cracks near Ban Doi Tio School in Nan Province. They found the cracks have expanded continuously from 2 meters to 100 meters and are accelerating risk assessment and protective measures.
Reporters said that ONRE Nan, along with the Regional Geological Office 1 and other related agencies, inspected cases of land subsidence, landslides, and soil cracks within Ban Doi Tio School area, Moo 7, Si Phum Subdistrict, Tha Wang Pha District, Nan Province, on 11 Sep 2026. This followed a request for expert assistance to assess the site conditions and evaluate the impact on school buildings and structures.
Ban Doi Tio School contacted ONRE Nan requesting personnel and geological experts to examine the subsidence and soil movement, which caused damage to the multipurpose building and concrete retaining walls. They also observed increasing cracks around the area.
Geological experts found several landslides and soil movements within the school grounds at coordinates UTM 47Q 0675751E 2113062N, about 1,116 meters above sea level. Local residents reported landslides beginning between May and July 2025, with continuous expansion from about 2 meters to approximately 100 meters long, especially during the rainy season.
Additionally, more ground cracks have appeared in several places, requiring close monitoring, especially during heavy rainfall or when water accumulates in the soil layers, which could cause further soil movement.
Damage and cracks were also found in buildings and structures inside the school. Surveys revealed fractures and structural damage in several school buildings, reflecting soil movement in the area. Continuous monitoring of cracks and structural conditions is necessary to assess safety and suitability for use.
Geological inspection showed the area rests on red-brown sandstone and mudstone layers that weather easily. Combined with terrain and water conditions during the rainy season, a thick clay sediment layer covers the surface. This makes the area sensitive to water saturation and soil movement, especially during prolonged rainfall.
According to landslide risk maps from the Department of Mineral Resources, the area is classified as having moderate to very high landslide potential. This matches the geological features and current soil movement observed, highlighting the need for continuous risk monitoring, particularly in the rainy season.
Following the inspection, related agencies will jointly monitor the situation and re-examine the site on 13 Sep 2026 to assess changes in cracks, soil movement, and impacts on buildings and surroundings, considering suitable monitoring and prevention measures to ensure safety for teachers, students, staff, and residents.