Two of major fault lines and sediment movement

Earth flow sediment

The Oi River upper river basin is sandwiched between two of Japan’s major fault lines, the Median Tectonic Line and the Itoigawa-Shizuoka Tectonic Line making the area subject to intense crustal deformation and the foundation in the area here collapses easily. Sandstone and shale formed on the ocean floor end of the Cretaceous period (approx. 60 million year ago) rose at an accelerated rate over the last several million years and at the same time severely corroded. As a result the Ikawa Forest Station boasts one of the country’s highest sediment yields and the sediment movement here is more active than any other university-owned field in Japan. A debris avalanche occurs virtually every year, and research is conducted on erosion control and topography that make use of this phenomenon. The movement of the forest’s soil and water is surveyed in exercises for acquiring knowledge and skills regarding the forest’s function and usage. We measure the effects climate change, changes in forest vegetation, and deforestation have on micro weather systems and soil movement, as well as carbon and nitrogen circulation. Topography and erosion control engineering research is also often conducted here.