Landslides in India
Introduction
Landslide refers to various processes that lead to the perceptible outward and downward movement of rock, vegetation, and soil under the influence of gravitational force (Smith et al. 2013). Both man-made and natural environmental changes can trigger landslides. In particular, the geological history of a region, along with human occupation activities has a direct influence on landslides. In India, landslides are a recurring phenomenon, resulting in the loss of lives and property. The essay seeks to examine the landslides in India in terms of causes and social, economic, and environmental impacts.
Landslides issues in India
Natural calamities such as landslides and earthquakes are responsible for nearly 4% of annual deaths globally. While the distribution of casualties owing to such natural disasters may not be even, developing countries such as India bears the greatest brunt on account of their high population density. The Geological Survey of India estimates that approximately 12.6% of the country’s land area is susceptible to the occurrence of landslides. Most of this land area is to be found in the Himalayan terrain (Geological Survey of India n.d.), implying that the region is also highly susceptible to earthquake-triggered landslides.
Causes of landslides
Geological causes
Geological causes of landslides include sensitive or weak materials, fissured, sheared, or jointed materials, as well as variations in stiffness and/or permeability of materials
Morphological causes
Landslides may also be caused by morphological events, including volcanic or tectonic uplift, thawing, and removal of vegetation by drought or fire, wave, glacial or fluvial erosion of lateral margins or slope toe, and subterranean erosion.
Anthropogenic causes
These include such activities as mining, deforestation, artificial vibration, irrigation, and loading of slopes.
It is important to note, however, a combination of these factors results in the most devastating landslides in the world. The Himalayas region is highly prone to landslides owing to such activities as mining and road construction, indiscriminate deforestation, and destruction of the natural dense forest cover due to grazing and increased population. These activities tend to destabilise the existing ecological balance, thus leading to the loosening of the soil. When heavy rains fall, soil erosion occurs, and this frequently triggers landslides.
Impacts of landslides
Landslides impact the social, economic and environmental aspects of life.
Social impacts
Landslides lead to the loss of lives and the associated grief and suffering of those affected. In addition, landslides displace communities from their usual habitat, not to mention the psychological and emotional suffering that they have to endure.
Economic
Landslides result in direct and indirect losses of both public and private property. Examples of direct costs include the costs of repair, rebuilding, or replacement of damaged infrastructure. Examples of indirect costs due to landslides are loss of revenue owing to property devaluation, reduced or lost human productivity owing to injury, death, or psychological traumas, and loss of property value in regions where landslides have occurred or are at risk of landslides. For example, a landslide in the Kedar valley in 2013 (shown in figure1 below) resulted in traffic stalling for hours due to heavy rains. This led to lost revenue for traders, not to mention the cost incurred by the government in repairing the road.
Public costs of landslides refer to the costs that the municipal, county, local, federal, and state governments have to bear.
Most of the public costs involve the repair and maintenance of damaged public infrastructure, such s roads. Other examples of public costs due to landslides involve relief and emergency needs by the police, fire department, and medical personnel. Public funds are also needed to support warnings, hazard evaluation, evacuations, and building inspections (Lu & Godt 2013). On the other hand, private costs refer to the costs borne by businesses and individuals following damages to buildings, and homes, among other personal property.
Environmental
Landslides could lead to prolonged effects on the environment. For example, landslides may also pollute water bodies such as streams and rivers with excess sediment. This could threaten fish habitat and water quality (Sassa & Canuti 2008). Landslides can also destroy wildlife habitats and forests, in addition to causing loss of productive soil in sloppy terrains.
Landslides have also been known to trigger tsunamis or outburst floods.
Evaluation
Landslides are a key threat to the lives of individuals, not to mention the social, economic and environmental impacts associated with them. Globally, nations dedicate a lot of funds toward the mitigation of these impacts (Burns et al. 2013). Landslides are a common occurrence in India and if we are to mitigate the social, economic and environmental effects of landslides, there is a need to identify and communicate potential landslides using effective tools such as LSM (landslide susceptibility mapping), which has been identified as a key component in disaster mitigation and management (Smith et al. 2013). Some of the corrective measures that the GSI has implemented include the construction of restraining structures, the use of ground anchors, and the planting of vegetation to stabilize landslides (Geological Survey of India n.d.).
References
Chauhan, C (2014). Desecration of environment has made Uttarkhand prone to floods,
landslides. [Online].
Geological Survey of India (n.d.). Overview. [Online].
Geological Survey of India (n.d.). Overview on Landslides. [Online].
Lu, N & Godt, JW (2013). Hillslope Hydrology and Stability. Cambridge: Cambridge University Press.
Sassa, K & Canuti, P (2008). Landslides-Disaster Risk Reduction. New York: Springer.
Smith, J.B., Godt, J.W., Baum, R.L., Coe, J.A., et al. (2013). Hydrologic Monitoring of a Landslide-Prone Hillslope in the Elliott State Forest, Southern Coast Range, Oregon, 2009–2012. [Online].
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