Dangers And Causes Of Landslides Environmental Sciences

Essay add: 11-01-2017, 17:18   /   Views: 8

Landslides are a major threat to human life, property and constructed facilitates infrastructure and natural environment in massy mountain regions of the world. As a consequence of climatic changes and potential globe warming, an increase of land slide activity is expected in some part of the world in the future. Climate is a dynamic component of the environment, which has a direct and indirect influence on man and his activities. Climate has never been the same over time and space. Most scientists agree that the global climate is changing. It has changed during the past century. The world agriculture is mainly influenced by rainfall than by other climatic elements. According to the common concept Mass wasting or mass movement of the soil is usually known as the earth slips.

2. The movement of masses of rock boulder, earth or collected debris down a slop is known as a land slide .when a slope has no proper drainage, the rain water is retained within the mass of soil. This causes the soil layers to be separated and the surface layer of soil which is heavy with the retained rain water tends to slide down the slope due to the gravitational pull. The sliding many be slow or fast defending on the steep mess of the slope. During heavy rain or storm these landslides can occur with little warning or without any warning at all.

3. The total land area of Sri Lanka is about 6.5 million hectare or 16 million acres; of this about one third has been utilized for plantations and agricultural holdings. A little over 20 per cent is under wood land, and about 6.4 per cent grass and scrublands. The Patten of the land use has been changing rapidly. In the past the population was small and forest covered most of the land. In the 19th century the population increased, and the forest decreased. A larger cleared area was necessitated by the ever increasing population for their living and agriculture. Large multipurpose schemes involving the construction of

reservoirs for irrigation agriculture, power generation and settling people in these areas by clearing the forest are other land usage that have occurred during this period. It also had an effect on the climatic change. A disaster is an event, natural or man-made, sudden or rapidly progressive. Continued deterioration of the environment, particularly through deforestation and land misuse is contributing to the frequency of natural disaster such as floods, droughts, and so on. Overcrowding of cities is increasing the vulnerability to disaster. In the developing high tech world disasters are manmade. Land slide is one of the most damaging disasters in Sri Lanka.

BACKGROUND

4. Extensive loses of life and property due to continuous rain have been reported from the highlands of Sri Lanka during the past thirty years. In the Rathnapura District more than 100 persons died in May 2003 due to floods and land slides.the hill slope in this area are very unstanabal so that during the rainy season land slide shave become a common feature. The principle natural hazard in Sri Lanka in the past was floods but today it has been replaced by landslides .Most of the slopes are steep and unstable as such they are subjected to move down during the rainy sea season Landslides have been reported with increasing frequent from the following districts in Sri Lanka, Badulla, Galle, Hambantota, kandy, Kegalle, Matara, Monaragala, NuwaraEleya and Kandy.

5. Climate of Sri Lanka can be divided in to four seasons. First inter monsoon (March- April), South west monsoon (May-September), second inter monsoon (October-November) and North East monsoon (December- February).According to the rainfalls pattern. Highest total area rainfalls receiving during the South West monsoon and second inter monsoon periods about 60 per cent of the total rainfall is received during these two monsoon periods.

6. Most of the land slides are caused by the rain water into the fractures of weathered rock. The land slides are associated with accumulating and flowing water on or below the surface in mountainous terrains. Newly formed landslides and reactivated ancient landslides have been monitored in Sri Lanka highlands. Landslides can be identified thousand along the hill slopes of many a location in the highlands. These previous landslides are in many instances stable under present condition.

7. Deforestation is one of the most effective environmental issues in Sri Lanka.Forest have been cut down to expand agricultural area and development.Defrorestion has led to landslide and floods. This is the most of effective reasons landslides in the central province of Sri Lanka.It may not be possible to prevent landslides good land management a reduction in their extent frequency can be achieved. Improve drainage system by diverting surface water and ensure safe disposal of excess water to well vegetated sites to prevent further erosin.This research is an attempt to study the climate change and human activates that have a direct bearing on land slides in Sri Lanka.

PURPOSE OF THE STUDY

8. Analysis have shown that the maximum and minimum temperatures in all metrological stations in Sri Lanka have clearly been increasing, with the highest increase of minimum temperature being about 2.0 C at Nuwara Eliya. Analysis of rainfall data reveals that the variability has been increasing in the past in most parts of the island resulting in water scarcities in the dry zone of Sri Lanka. The Initial National Communication on Climate Change (INC) prepared in 2000, by then Ministry of Forestry and Environment has identified that agriculture, water resources and human health services would be more vulnerable to climate change in Sri Lanka,this indicates that very few sectors agriculture, plantation and land use have developed suitable adaptation strategies to face this problem. The human settlements, public utilities such as water supply, road and other infrastructure would be seriously affected due to climate change.

9. The purpose of this research is to discuss the link between land slide and climate change and human activities. The total land area of Sri Lanka is about 6.5 million hectare or 16 million acres of this about one third has been utilized for plantations and agricultural holding. A little over 20 per cent is under wood land, and about 6.4 per cent grass and scrublands. The Patten of the land use has been changing rapidly. In the past, the population was small and forest covered most of the land. In the 19th century the population increased the forest cover area decreased. The area covered by settlement has expanded with population. Large multipurpose schemes involving the construction of reservoir for irrigation agriculture, power generation and settling people in these areas by clearing the forest are other land usage changes that have occurred during this time. The same has happened to climate change. A disaster is an event, natural or manmade, sudden or rapidly progressive. Continuing deterioration of the environment, particularly through deforestation and land misuse is contributing to the frequency of natural disaster such as floods, droughts, and so on. Overcrowding of cities, increase the vulnerability to disaster in the developing high tech world man-made disaster. Land slide is one of the most vulnerably disasters in Sri Lanka.

PROBLEM STATEMENT

10. Climate change and urbanization developments result in increasing landslides in the central province of Sri Lanka. Can the effect of human activities be controlled and thereby reduce the occurrence of land slide in the central province.

SIGNIFICANCE OF THE STUDY

11. Land slide represent a major threat to human life, property, constructed facilitates infrastructure and the natural environment in many mountain regions of the world. Therefore it is worth studying to know as to why and how these slides occur and also to find possible ways and means of preventing landslides.

SCOPE AND LIMITATIONS

12. Since the problem at hand is not static this research attemfot has its own limitations but yet, all efforts are taken within the given time frame to go through the maximum available literature, facts and data regarding seasonal timing, magnitude are frequently of landslides under new climate changes to identity the connection between change of climate and landslides. The necessary data collection and identification are at the country level.

Article name: Dangers And Causes Of Landslides Environmental Sciences essay, research paper, dissertation