Impact of Rainfall-Induced Landslide Susceptibility Risk on Mountain Roadside in Northern Thailand

Abstract

Landslide incidents frequently occur in the upper northern region of Thailand due to its topography, which is mostly mountainous with high slopes. In the past, when landslides happened in this area, they affected traffic accessibility for rescue and evacuation. For this reason, if the risk of landslides could be evaluated, it would help in the planning of preventive measures to mitigate the damage. This study was carried out to create and develop a risk estimation model using the artificial neural network (ANN) technique for landslides at the edge of the roadside, by collecting field data on past landslides in the study areas in Chiang Rai and Chiang Mai Provinces. A total of 9602 data points were collected. The variables for forecasting were: (1) land cover, (2) physiographic features, (3) slope angle, and (4) five-day cumulative rainfall. Two hidden layers were used to create the model. The number of nodes in the first and second hidden layers were five and one, respectively, which were derived from a total of 25 trials, and the highest accuracy achieved was 96.74%. When applying the model, a graph demonstrating the relationship between the landslide risk, rainfall, and the slopes of the road areas was obtained. The results show that high slopes result in more landslides than low slopes, and that rainfall is a major trigger for landslides on roads. The outcomes of the study could be used to create risk maps and provide information for developing warnings for high-slope mountain roads in the upper northern region of Thailand.

Assessment of Landslide Susceptibility in the Intermontane Basin Area of Northern Thailand

“…In the context of Chiang Mai, many landslides are noted on slopes with angles ranging from 15° to 35°. This finding aligns with the research by Dechkamfoo et al (2022), signifying that slope angles of 15° to 30° are prone to triggering landslides in northern Thailand.…”

“…This region is geologically diverse, primarily consisting of sedimentary and metamorphic rocks alongside igneous formations (Yongsiri et al, 2023). These rock types' differential weathering rates lead to soils forming with varying cohesion and erosion resistance (Dechkamfoo et al, 2022). These geological and soil characteristics significantly influence the region's susceptibility to landslides.…”

Factors affecting bus accident severity in Thailand: A multinomial logit model

“…Crashes occurring in Northern Thailand are more likely to cause in injury or fatality compared to non-injury, respectively. This might be due to the fact that landslides occur in the upper northern region of Thailand, where the roads are mostly curved and the terrain is mountainous [ 59 ]. Moreover, Phayao was found to have the highest fatality rate (60.0%) of all provinces.…”

The Production of Safety School Space from Climate Disasters in Doi Mae Salong Forest, Upland Northern Thailand

“…In Doi Mae Salong forest, a landslide caused by heavy rain, flooding, monsoons, and typhoons is a severe threat that might cause calamity in this hilly region. Landslides happen in the highlands on steep slopes with no internal balance and hillsides with little tree cover to absorb rainfall (Dechkamfoo et al, 2022). As a result, the disastrous occurrence has caused an estimated economic loss of 15 million Baht (UNICEF, 2016).…”

“…According to Dechkamfoo et al (2022), rainfall is the main factor determining landslides in the Doi Mae Salong landscape. When the rain is saturated with the land cover, the steep slopes on hillsides collapse from the high terrain.…”