Landslides are very common phenomenon in Kashmir particularly along the Jammu- Srinagar national highway. Roads get blocked every year due to frequent landslides in the area. Come the rains, the landslides occur. The land slides are temporarily every year shutting the Kashmir valley isolated from mainland India. In winters, when the connectivity is all more important. This is when the landslides struck the most, leading to shortage of food grains, vegetables and other essential commodities. It leads to temporarily inflation in the prices of essential commodities. Landslides are downward, outward movement of mass of rock, debris or earth along the slope. Landslides occur under the influence of gravity. Heavy rains trigger landslides in different areas. Rains saturate the soil over course of time which makes the soil susceptible to downward movement under the influence of gravity. Landslides occur when forces acting down slope (gravity) exceeds the strength of the materials forming the slope. The landslides occur mostly in areas which are geologically unstable. Any more pressure on these areas would lead to landslides. Construction of roads, dams, houses etc would increase the chance of landslides in already unstable or just stable slopes. The tendency of landslides to form is influenced by many outside factors. Climate is important as it influences the accumulation of water which precedes the landslides and trees which can influence the soil stability. Although it would seem tree roots should stabilize the soil, but the ability of the trees to add significant mass to the slope by accumulating water and destabilize the soil by aiding water infiltration may have an opposite effect making the slope land-slide prone. The landslides are often deep seated, the tree Plantations on slopes which are not suited for trees geologically could have more landslides when planted with trees. The barren land is more prone to landslides as compared to the vegetated area. As vegetation hold the soil particles together, preventing it’s loss. The type of landslides which could be prevented by vegetation is erosion. As erosion is also a landslide, as it removes the soil down the slope.
Like on the land, landslides occur in oceans too. The rock, debris or earth would move down slope under the water too. These landslides under the water sometimes lead to the Tsunami causing massive destruction along the coasts. The Tsunami occurs as a string of waves catching people all of a sudden. Though most of the Tsunamis occur due to earth- quakes. Some occur due to under water landslides too. Kashmir valley being present in seismic zone V. The chances of occurrence of earth-quakes are significant. Earth quakes have the ability to trigger massive landslides. The chances of landslides increases many times, if the the soil is already saturated with water. This result in the type of landslides called mud-slides or mudflows, where wet debris flows down the slope. The areas where clayey soil is present, the landslides occur after the rains have stopped and soil has started to dry. Clayey soil is elastic it elongates when saturated and contracts on drying. After the rainfall in such areas, the clayey soil on drying contracts and develops large furrows/cracks within a large land mass. These split landmasses, are not able to sustain on their own against the gravity, hence move down slope in the form of landslides. In such areas, maximum threat of landslides is just after the rains when soil is starting to dry. Landslides have to do with geology of the areas. The slopes which are geologically devoid of trees are most likely not suitable for tree vegetation. Going for tree plantation without any regard to the geology of the area could prove counterproductive. It could increase the incidence of landslides in the area. It would be shallow thinking that tree plantation would prevent the incidence of landslides. It could most often than not prove otherwise. As many times, it has been seen that landslides have occurred in well forested areas. Landslides occur in only some areas where land slopes are weak. The gravity is proving strong enough to move the rock, debris, soil etc downwards. In some areas, where the landslides were not occurring previously and the slope was just stable to prevent landslides. The downward force of gravity and the strength of the materials composing the slope were just balancing each other. A small precursor in the form construction of roads or other activity would lead to massive landslides. First and foremost, the areas which are just stable geologically must be avoided for any type of developmental activities. But if that is not possible, then concrete bunds must be constructed at suitable places to enhance the stability of the place which would result in fewer incidences of landslides. Besides, the accumulation of rain water must be prevented too by plugging the rills, which would otherwise lead to formation of gullies and ravines. Accumulation of water would loosen the soil, making it prone to landslides.
(The author is a freelancer. Views are his own)