11.1 Introduction

Landslides are geological phenomena causing flow of rock, earth, or debris flows on slopes due to gravity in coastal, offshore or onshore environment. It also known as mud flows, debris flows, earth failures, slope failures, etc., and can be triggered by rains, floods, earthquakes, and other natural causes as well as human-made causes, such as grading, terrain cutting and filling, excessive development, etc.


The factors affecting landslides can be geophysical or human-made, they can occur in developed areas, undeveloped areas, or any area where the terrain was altered for roads, houses, utilities, and buildings. The down-slope movement of material is further subdivide into two broad categories i.e. Slope Failures and Sediment Flows.