11:00 AM - 11:15 AM
[HGG02-07] Long-term monitoring of trail degradation in Daisetsuzan National Park and future trail management
Keywords:National Park, Trail degradation, Trail management, Long-term monitoring, Three-dimensionalization
Trails are essential infrastructure for trekkers/hikers to reach mountain summits and mountain lodges, and trails also play a role in protecting the natural environment from use. However, the location and design of trails focus on the convenience of walking, and not necessarily on the vulnerability of the natural environment. As a result, trail degradation such as trail erosion has become a problem in many national parks and nature reserves, including those in other countries. However, the personnel and budget required for the maintenance and management of national parks in Japan are not necessarily sufficient. The lack of proper management of degraded trails has led to a vicious cycle of further degradation caused by heavy rains that have occurred in recent years.
In light of this situation, Daisetsuzan National Park, located in the center of Hokkaido, began repairing trails with the help of volunteer trekkers/hikers in 2017. However, owing to the limited frequency of trail monitoring in Daisetsuzan National Park, the prioritization of trails for repair and the scientific basis for this prioritization are inadequate.
In this study, long-term monitoring using three-dimensional measurement methods, such as UAVs and pole photography, was conducted from 2014 to 2022 to clarify changes and trends in trail degradation. The survey was conducted by dividing the trail into ten sections that pass through flat landforms formed by lava flows and pyroclastic deposits called Hokkai-daira at an elevation of approximately 2,060 m.
The first survey was conducted in 2014. In the first survey in 2014, a large amount of degradation (>200 m3) was already observed in survey sections on the southeast-facing slope where clayey soil was developed. However, during the eight years of long-term monitoring from 2014 to 2022, erosion of more than 10 m3 was observed in the study sections covered by pyroclastic flow deposits on the northwest-facing slope, showing a larger amount of erosion than in the study sections located on the southeast-facing slope. This indicates that each study section responded differently to heavy rainfall events, with daily precipitation exceeding 80 mm that occurred in 2016, 2018, and 2022. These results indicate that identifying changes in erosion rates is important in determining trail sections that should be repaired.
In the sensitive environment of Daisetsuzan National Park, repair work needs to be conducted carefully, and long-term monitoring is essential. However, it is impractical to cover the entire 300 km of trails owing to the lack of specialized staff and budget. Therefore, as in the case of repair work, the participation of volunteer trekkers/hikers may play a significant role in acquiring basic data essential for decision-making in trail maintenance and management.
In this study, UAVs and pole photos were used, but Apple's iPhone is equipped with Lidar, which makes it relatively easy to acquire three-dimensional data. The establishment of a data-collection platform and feedback system will provide value in the contribution to the conservation of the natural environment. Long-term monitoring using three-dimensional data and the cooperation of volunteer trekkers/hikers are essential for enhancing the value of national parks and the sustainable use of mountain trails.
In light of this situation, Daisetsuzan National Park, located in the center of Hokkaido, began repairing trails with the help of volunteer trekkers/hikers in 2017. However, owing to the limited frequency of trail monitoring in Daisetsuzan National Park, the prioritization of trails for repair and the scientific basis for this prioritization are inadequate.
In this study, long-term monitoring using three-dimensional measurement methods, such as UAVs and pole photography, was conducted from 2014 to 2022 to clarify changes and trends in trail degradation. The survey was conducted by dividing the trail into ten sections that pass through flat landforms formed by lava flows and pyroclastic deposits called Hokkai-daira at an elevation of approximately 2,060 m.
The first survey was conducted in 2014. In the first survey in 2014, a large amount of degradation (>200 m3) was already observed in survey sections on the southeast-facing slope where clayey soil was developed. However, during the eight years of long-term monitoring from 2014 to 2022, erosion of more than 10 m3 was observed in the study sections covered by pyroclastic flow deposits on the northwest-facing slope, showing a larger amount of erosion than in the study sections located on the southeast-facing slope. This indicates that each study section responded differently to heavy rainfall events, with daily precipitation exceeding 80 mm that occurred in 2016, 2018, and 2022. These results indicate that identifying changes in erosion rates is important in determining trail sections that should be repaired.
In the sensitive environment of Daisetsuzan National Park, repair work needs to be conducted carefully, and long-term monitoring is essential. However, it is impractical to cover the entire 300 km of trails owing to the lack of specialized staff and budget. Therefore, as in the case of repair work, the participation of volunteer trekkers/hikers may play a significant role in acquiring basic data essential for decision-making in trail maintenance and management.
In this study, UAVs and pole photos were used, but Apple's iPhone is equipped with Lidar, which makes it relatively easy to acquire three-dimensional data. The establishment of a data-collection platform and feedback system will provide value in the contribution to the conservation of the natural environment. Long-term monitoring using three-dimensional data and the cooperation of volunteer trekkers/hikers are essential for enhancing the value of national parks and the sustainable use of mountain trails.