Study of Recent Landforms Evolution and Mountain Hazards Mapping in Kamikouchi, the Japanese Alps

长野县上口内地区位于日本中部的日本阿尔卑斯山南部，代表了典型的阿尔卑斯山景观。一些旅游设施对最近游客人数的增长很有帮助，但受到周围山区沉积物造成的灾害的威胁。因此，在河道中实施了泥沙控制工程。然而，自然保护组织抗议那些打算建造更多工程和结构的工程师。目前，对上口内地区的地貌演变和灾害的评估已成为迫切需要。对整个研究区的近、古地貌和地貌过程以及由此造成的灾害进行了调查和制图。以1：25 000的比例绘制了各种地貌过程（落石、滑坡、泥石流和水活动）的地图，并以相同比例绘制了灾害程度的地图。结果表明，稳定区域似乎是有限的小区域，相应地，许多设施处于危险之中。如果要保护它们，就需要更多的结构和工程。这样的建设必然导致景观和地貌平衡的彻底破坏。上口内的环境脆弱，极易受到干扰。

The Kamikouchi District, Nagano Prefecture, located in the southern part of the Japanese Alps, Central Japan, represents typical alpine landscapes. Some tourist facilities, which are useful for recent growth in the number of tourists, are threatened by sediment related disasters from surrounding mountains. Therefore, sediment control works have been practiced in stream channels. Nature conservation groups, however, protest against engineers who intend to construct more works and structures. At present, assessment of the geomorphological evolution and disaster has been strongly required in Kamikouchi. Recent and past landforms and geomorphological processes, and resulted past disasters were investigated and mapped in the whole study area. Various geomorphic processes (rockfalls, landslides, debris flows, and water activities) were mapped on the scale of 1:25 000, and degrees of hazards were also mapped on the same scale. The results show that stable area seems to be limited in small areas, accordingly, many facilities are in danger. If one intends to protect them, more structures and works are necessary. Such construction surely leads to complete damage of the landscapes and geomorphological equilibrium. The environments in Kamikouchi are fragile and highly susceptible to disturbance.