Soil Erosion of Mountain Trails at the Mt. Hohuan Area

• Main Authors: Jieng-Zhi Su, 蘇敬智
• Other Authors: Yue-Joe Hsia
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/6sm9zp

碩士 === 國立東華大學 === 自然資源管理研究所 === 94 === Trails especially unattended trails in alpine area could cause serious soil erosion problem along the route. Recently, recreation activities at Mt. Hohuan recreation area in the Taroko National Park are escalating alarmingly. Soil erosion along seven trails with a total length of 14.55 km at Mt. Hohuan was surveyed. Each trail path was divided into 30-meter sections and maximum soil erosion depth, path width, and section slope were measured. Impact of visitors on those trails was also estimated based on questionnaire conducted during the night at the Hohuan and Kuanyun lodge. Soil erosion impact caused by seven trail paths around the Hohuan area were assessed based on soil erosion depth, path width, and amount of soil erosion. Sideslope and aspect were calculated by digital terrain model. Relationship of soil erosion, path width, path slope, slopeside, aspect and number of visitors were investigated mainly based on correlation analysis. Survey result indicated that the critical factor that influence trail erosion depth is trail slope. Erosion depth at 4 trails were significantly correlated with trail slope except Mt. North-Major Trail and Mt. Shihmen Trail. There are better vegetation coverage and soil condition along the trail such that the soil erosion problem is somewhat eased at Mt. North-Major Trail. At Mt. Shihmen Trail, however, the erosion depths at flat slope were deeper than expectation possibly due to some past engineering works along the trail. Slope length is another factor that influence trail erosion depth. There are four trails which show traces of engineering works. Among them, soil erosion depth at sections which had traces of past engineering works along 3 trails, except Mt. Major- Wuling, shows deeper soil erosion than those sections without engineering works. Trampling caused by visitors, however, is the primary agent of trail widening. Survey result also indicated that the width of minor trail sections are narrower than that at major sections of trails. Finally, in order to remedy the soil erosion problem at those high mountain trails, it is suggested that Mt. North-Minor Trail and Mt. East- Sunghsueh Lodge Trail could be closed at least temporarily because there are alternative trails available. For trail sections that erosion depth deeper than 30 cm and longer slope length remedial works such as water bars could be installed.