On the Possibility of Judging the Effectiveness of Groundwater Drainage Works by Measuring One-meter-depth Temperature

Take the case of the Oh-ishi landslide area

Abstract

Investigating method of one-meter-meter-depth temperature measurment was carried out in the Oh-ishi landslide area belonging to the metamorphic rocks zone for the first time in February 1980. On the basis of the results, groundwater drainage works were carried out. In this time, the investigating method was carried out again in the same area in February 1983 for examining the reproducibility of temperature distribution and the introduced variation by groundwater drainage works.
As the results, next matters were shown:
1) The reproducibility of the temperature distribution was recongnized clearly in a landslide area belonging to the metamorphic rocks zone.
2) The effectiveness of groundwater drainage works was recognized satisfactorily by the observed results of groundwater level and the quantity of drainage in groundwater-vein streams.
3) The possibility of judging the effectiveness of groundwater drainage works was shown by comparingwith the φ_z=1-y diagrams and the distributing diagrams of underground temperature before and aftergroundwater drainage works.