Landslide Survey
Landslides refer to a variety of processes that result in the movement of soil and rock downslope, which can range from a single rock to an entire mountain. Their occurrence is usually due to prolonged rains, earthquakes or the cutting off of the ground surface. Landslides are particularly dangerous as they can cause extensive damage to buildings, roads, and other vital infrastructure. They can lead to loss of human life and devastating economic losses. Whenever there is a potential landslide risk, it is essential that a landslide survey is conducted.
A landslide survey is a detailed examination of the slope, bedrock and soil conditions to identify areas with the potential for future landslides. The ultimate goal of a landslide survey is to predict when and where a landslide might occur and the intensity of the landslide. A team of geologists and engineers are tasked with assessing the various factors that contribute to a landslide, such as unstable bedrock geology, highly erodible soils, or conditions that could cause a shift in water drainage. In addition to field observations, aerial imagery and geological maps are used to identify and classify areas of concern.
The survey team will first identify and classify any large-scale fail soils, such as landslides, earthflows, and rock slides. Depending on the scale of the survey, the team will also identify and classify minor soil movements such as soil creep. After the initial reconnaissance, detailed field measurements are taken to identify failure and movement characteristics. Soil strength, moisture content, and soil structure are all important parameters to measure and record. The topography of the area is also recorded to help identify any drainage issues or rainfall runoff problems. Core samples may be collected to further assess the stability of individual features on a slope as well as to gain insights into the type of soil layers present.
Once a potential failure has been identified, an independent assessment is usually called for to identify the potential hazard and determine the necessary mitigation measures. A wide variety of practices can be employed, such as improving drainage by installing drainage systems, strengthening the slope with embankment or buttress walls, or using reinforcing meshes to stabilize the soil and rock.
Landslide surveys are important in reducing the risk of landslides and the related destruction that landslides cause. By remaining vigilant and proactively addressing potential risks, we can help lessen the impact of future landslides.
