The phenomena of sliding of weak and unstable soil, rocks and other materials from a certain height to the downside due to the action of gravity and various factors or causes which we will discuss below are said to be “Landslide“.
Mainly, a landslide occurs in hilly and mountainous regions where there is a high chance of having weak and unstable soils, rocks and sands. There are many trigger causes of the landslide. There are two kinds of causes of the landslide which are the most responsible for frequent landslide; Natural causes and human causes.
Causes of landslide
1.Natural causes of Landslide
Every existing in the surrounding is associated with nature. Everything present is gifted by nature and we are users of it and it’s nature greatness. But sometimes due to imbalance in nature or fluctuation in the operation of the ecosystem, there is great effect resulted in disasters known as natural disasters. For instance, landslide, soil erosion, flood, earthquake, .etc.
There is a variation in the land structure somewhere there is plain land whereas at someplace uneven, sloppy with different slope aspect and gradient and we know that at sloppy area there is great chance of being weak and unstable land and at this place, there is high pressure of water flow which causes devastating flood and finally resulted out as landslide too. Due to dip spacing under the roots of the tree from the surface, there is the slow movement of bedding planes and along a line of weakness in a fault in a soil property cause landslide. And if the strength of large rocks is not good they rolled down and this process of rolling down of rocks with sliding it’s ways materials too is considered to be a landslide.
Under the surface of the earth, there are many tectonic plates which are responsible to maintain the stability of earth’s surface thus we are capable of moving here and there and standing in one place. When these tectonic plates move unwisely the earth surface quakes which is said to be “Earthquake”. And the shaking of earth surface resulted out as various natural disasters among them landslide is one. Tectonic plates are above the molten liquid known as lava on the earth’s surface. So, Uneven movement of tectonic plates can cause the eruption of lava from a certain area mainly from hills of rocks known as “Volcanic Eruption. The volcanic eruption also can cause landslide which is more disastrous than other causes of the landslide.
Due to variation in the geography of the earth, the weather differs from place to place. So, in some regions, there is cold, moderate, hot, etc. and weather causes disturbances in the ecosystem of the earth and leads to many kinds of problem like weakness in the quality of soil, rocks, roots of trees become weak to hold soil and landslide occur. And also cause soil erosion and in mountainous regions, there is snow, glaciers whose effect as thawing, freeze-thaw, etc. resulted in landslide causes great loss of property and lives.
At a dense forest area, there are great possibilities of heavy rainfall. And Heavy rainfall is a frequent trigger cause of the landslide. Hydrogeological Factors which can cause landslide are Geomorphology, soil types, and elevation. And slow snowmelt can cause avalanches flood.
On the sloppy land, there is a high possibility of glacier erosion, soil erosion, wave erosion( erosion due to movement of waves of seismic waves), fluvial erosion(erosion with the flow of water of streams), etc. And the change in vegetation can bring change in climate change and finally landslide.
Depending upon the porosity of rock(cracks or cavities of the rocks ) there is a measure to identify the easiness of flow of fluid through porous rocks. And this measure is known as Permeability contrasts. If we are unable to find out porous point in rock there is high of landslide with forceful flood and rocks sliding down.
2.Human Causes of Landslide
Due to unwise use of resources available in nature by human various problems are causing with very impact on nature and living beings. Some of the Human causes responsible for a landslide are described below:-
Chopping down of plants is termed as deforestation. With the development, the rate of deforestation is also increasing day by day which is the result of the need for the high population of users. Human chopped down plants for their benefits like for furniture, foods, as raw materials for the operation of industries and factories, etc. They are destroying forest but they are messing up the various natural disasters. They can use forest but also they heal the loss of greenery by planting more plants than they chopped down. We all know that plants’ roots are responsible to hold soil and not to let it slide down. With an increase in deforestation probability of landslide increases at a high rate.
The activity of using tools, equipment, or explosives to move some materials, rocks, soil, and for exploration, environmental restoration, mining and constructions are called excavation. During excavation surface of the earth’s shake and the area where this is done becomes weak and can result out as landslide at that place.
Improper water management in the water resources like we can manage water resources like rivers, streams, etc. from over water flowing and as continuous water flow can weaken the soil and rocks. And the area with weak and unstable soil and rocks have a high chance of landslide.
Improper use of land for various constructions like roads, buildings, dams, bridges, and many more by destroying nature.
Excessive use of land can cause urbanization and it has a bad impact. For construction purpose various heavy equipment are used as rollers, crane, land piercing machines for drilling, etc. which causes vibration and surface shake and landslide occurs.
For quarrying(the process of extracting materials, from ground or crushing rocks by blast furnace,etc. ) and Mining (the process to extracting out precious and valuable substances from ground like gold, diamond, etc.) various tools are used like sheared materials, drilling materials etc. creates temporary quakes in the surface and causes landslide.