学会誌「自然災害科学」

数値標高モデルに基づく豪雨による斜面崩壊危険度予測 －長崎市を事例対象として－

Prediction of Slope Failure Potential Induced by Heavy Rain Using Digital Elevation Model - A Case Study for Nagasaki City -

水田 敏彦*・瀬尾 和大*

Toshihiko MIZUTA* and Kazuoh SEO*

Abstract

In this paper, an attempt is made to construct and utilize a database for the assessment of the slope failure potential. It was based on a 50-m grid digital elevation model (DEM) of Nagasaki City. Three morphometric maps of drainage network, slope direction and slope angle classification were created. Real rain data, slope inclination and soil parameters were assigned to each mesh, as well as a depth of a potential failure layer. In the layer, the infiltrated water movement from mesh to mesh was modeled. Using this model it is possible to calculate the infiltrated ground water levels, for every mesh and every hour which show the three-dimensional effects of a topographical factor in an area. These data along guide with groundwater movement model were used to calculate the ground water level and slope stability. As a result the "heavy rain-type" slope failure is being assessed quantitatively.

キーワード:

Key words: