Study on Landslide Category Base on Temporalspatial Characteristic Distribution in Northern Vietnam Using Satellite Images

Abstract

North Vietnam is a lot of landslide generate region due to heavy rainfall or tropical storms, Steep slopes on mountainous sides and human activities such as road or house constructions. Heavy rainfall events are estimated by climate change in the future. Therefore, it is necessary to understand landslide characteristic due to rainfall variation. This paper applied Landsat satellite images and calculated NDIs (Normalized Difference Indexes) to evaluate the condition of vegetation, soil and water and detected 87 landslide points in North Vietnam. And, landslide points are evaluated to compare digital geographic information data to divide landslide type. As result, three typical types of landslides are classified as landslide caused by rainfall on construction (Road etc..) sites (Type1), a landslide caused by rainfall on natural slopes(Type2), and landslide caused by rainfall and water drawdown on banks of reservoirs or streams(Type3). Considering the Landsat result Type 2 and Type 3 consist larger proportions compared to those in historical data. This means that many landslides would occur in mountainous areas that far from residential or road areas (Type1).