The Reconnaissance Survey of Landslides in Soft Rocks Area using the New Type HEM System

Abstract

The new type Helicopter-borne Electro-Magnetic (HEM) system, which has been improved the frequencyrange of measurement to meet the needs in civil engineering fields, has been applied to the landslides of Sarukuyoji in Niigata prefecture and Yachi in Akita prefecture.
The results of HEM survey show that both landslides correspond to the anomalous low resistivity zones, which shows that HEM method is effective to detect and delineate the landslides accompanied with cohesive soil, collapse soil or weathered zone.