Evaluation of cost and benefit of sediment based on landslide and erosion models

Sediment hazard mapping is a fundamental tool for disaster management and mitigation activities in Thailand. Several countries are at risk of suffering landslide damages, but few studies have focused on the quantitative estimate of damages at a large scale. Most studies have considered the effects of landslide and soil erosion events from the perspective of their economic drawbacks, and there is no consensus on the quantitative assessment of the positive economic impacts of these events. Therefore, this study aimed to support the future assessment of landslides and other soil erosion events on sediment resources from positive economic perspectives. The results showed that the expected annual landslide damage cost in Thailand is approximately 204,000 USD per square kilometer. The cost for dredging sediment in Thailand is 108 USD per square kilometer. However, the benefit of sediment to private sectors is cost more than an average of 2040 USD per square kilometer, and the benefit values increased to approximately 15,000 USD per square kilometer in areas upstream of dams. In addition, there is an average benefit of 16,627 USD per year to the public sectors in each subdistrict of Thailand.