Prediction of Deep-Seated Landslide Sites on the Basis of Hydrogeomorphological Study

1997年7月10日，鹿儿岛县西北部的泉市发生了一次深埋山体滑坡。本研究的目的是准备一个实用的地图，预测高潜在的深层滑坡网站的侧翼的老火山山。弥羽岳在野外调查的基础上，分析了该滑坡的形成机理、滑坡坡位的地质和水文地貌特征。结果如下：1。在安装在山流域的水文观测站。连续测量了溪流的水、水流量、温度和电导率。虽然这些流域位于同一侧翼，但其径流特征随缓坡率、风化程度、切割程度等因素而变化。我们测量了基流，水温和电导率在17个溪流周围的山。弥羽岳这些值取决于缓坡和深风化岩石的空间分布和切割程度.对滑坡发生地坡脚地下水流量进行了实测。地下水流量的峰值比降雨量的峰值晚几个小时。这一结果与1997年7月滑坡发生时的结果一致。基流和电导率为每一个海拔在山上周围的溪流。弥羽岳被测量。因此，这些值的变化在海拔的深层次滑坡疤痕。流量和电导率的河流是预测潜在的深层次滑坡网站的重要因素。

A deep-seated landslide occurred at Izumi City in northwestern Kagoshima Prefecture on July 10,1997. The purpose of this study is to prepare a practical map for predicting high potential deep-seated landslide sites on the flank of the old volcano of Mt. Yahazu-dake. The mechanism of this landslide, and the geological and hydrogeomorphological characteristics of the landslide slope sites are examined based on field study. The results are as follows :1. In the hydrological observatories installed in the basins of Mt. Yahazu-dake, discharge, temperature, and electrical conductivity of the stream water were measured continuously. Although these basins are located in the same flank, the runoff characteristics changes with the rates of gentle slope, the degree of weathered rocks, and the degree of dissection, etc.2. We measured the base flow, water temperature, and electrical conductivity at 17 streams around Mt. Yahazu-dake. Those values depend on the spatial distribution of gentle slope and deeply weathered rocks, and the degree of dissection.3. The discharge of groundwater at the foot of the hillslope where the landslide occurred were measured. The peak of groundwater flow is several hours behind the peak of rainfall. This result is harmony-like as the time of landslide in July, 1997.4. Base flow and electrical conductivity for every altitude at the streams around Mt. Yahazu-dake were measured. Consequently, these values changed at the altitude of the deep-seated landslide scar.The discharge and electrical conductivity of stream are the important factors in predicting the potential deep-seated landslide sites.