Landuse Type of Slopes in Landcreep Zones in Mineoka Range, the Boso Peninsula, Central Japan

Abstract

The object of the present paper is to clarify the factors of the intensive cultivation and the peculiar types of landuse on the mountain slopes where landcreeps occur frequently, considering the relationship between the landuse and the geomorphological conditions such as height, slope angle, and micro-landforms on the southern slopes of Mineoka Range, the Boso Peninsula, Central Japan.The results obtained are summarized as follows;1) On the upper part of the slopes reaching about 200-250m a. s. l. there are paddy field. On the lower part, vegetable gardens and orchards are located about 100-150m a. s. l.. The land on the mountain side about 100-150m a. s. l. and near the ridge about 200-250m a. s. l. is used for housing.2) Gentle slopes (10°-15) reach to 200m a. s. l. on the southern slope of Mineoka Range and there are also flat surfaces (10° below) around the ridge about 300-350m a. s. l..3) The slopes are classified into 6 types of micro-landform units such as concave gentle slope flat surface, steep slope, three types of convex gentle slope; ridge type, “Inserberg” type, and terminal accumulation type composed of debris. These micro-landforms are characteristic on the landslide slopes.4) The areas of intensive land-utilization are concordant with the gentle slope of which slope angle is below 15° and the land-utilization is presumed to depend on the micro-landforms. For example, the concave gentle slope is used as paddy field, and the flat surface is adapted for housing site.