Page 1 of 11

European Journal of Business &

Social Sciences

Available at https://ejbss.org/

ISSN: 2235-767X

Volume 07 Issue 05

May 2019

Available online: https://ejbss.org/ P a g e | 1584

Landslide – Environmental Hazards and Rehabilitation Measures

LAKSHMANAN. C

PG Student

PRIST (Deemed to be University), THANJAVUR.

Abstract - In India, landslides are a serious geologic hazard common to almost every State. As people move into

new areas of hilly or mountainous terrain, it is important to understand the nature of their potential exposure to

landslide hazards, and how cities, towns, and counties can plan for land-use, engineering of new construction and

infrastructure which will reduce the costs of living with landslides. Geologic investigations, good engineering

practices, and effective enforcement of land-use management regulations can reduce landslide hazards. It is also

important to understand the science of landslides – their causes, movement characteristics, soil properties, the

geology associated with them, and where they are likely to occur. Warming of the Earth climate system is

unequivocal. That climate changes affect the stability of natural and engineered slopes and have consequences on

landslides, is also undisputable. Less clear is the type, extent, magnitude and direction of the changes in the stability

conditions, and on the location, abundance, activity and frequency of landslides in response to the projected climate

changes. Climate and landslides act at only partially overlapping spatial and temporal scales, complicating the

evaluation of the climate impacts on landslides.

Keywords: landslides, disasters, terrain, hazard, soil, climate.

The movement of a mass of rock, debris or earth, down a slope, when shear stress

exceeds shear strength of the material. In literature a wide variety of names have been used for

the denudational process whereby soil or rock is displaced along the slope by mainly

gravitational forces. The most frequently used are: Slope movement, Mass movement, Mass

wasting and Landslide. In the last few decades landslide is the term most used, though in the

narrow sense of the word (sensu strictu) it only indicates a specific type of slope movement with

a specific composition, form and speed?

Regions those are generally prone to landslides are: On existing landslides - old or recent,

on or at the base or top of slopes, in or at the base of minor drainage hollows, at the base or top

of an old fill slope, and at the base or top of a steep cut slope. Regions those are generally safe

from landslides are: On hard, non-jointed bedrock that have not moved in the past, on relatively

flat-lying areas away from slopes and steep river banks, at the top or along the nose of ridges and

set back from the tops of slopes.

Features that might be noticed before major landslides are: Springs, seeps, or saturated

ground in areas that have not typically been wet before, new cracks or unusual bulges in the

ground, street pavements or sidewalks, soil moving away from foundations, ancillary structures

such as decks and patios tilting and/or moving relative to the main house, tilting or cracking of

concrete floors and foundations, broken water lines and other underground utilities, leaning

telephone poles, trees, retaining walls or fences, offset fence lines, sunken or down-dropped road

beds and sudden decrease in creek water levels though rain is still falling or just recently

stopped.

Page 2 of 11

European Journal of Business &

Social Sciences

Available at https://ejbss.org/

ISSN: 2235-767X

Volume 07 Issue 05

May 2019

Available online: https://ejbss.org/ P a g e | 1585

Socio-Economic Impact of Landslides

Landslides pose serious threats to settlements, and structures supporting transportation,

natural resources management, and tourism. Furthermore, single events can claim several

hundreds of casualties. Landslides have crippling effect on the economy of the region by

damaging infrastructure, crops and productive assets of population besides, imposing huge

burden on relief and rescue operations. Globally, landslides cause approximately 1000 deaths a

year with an estimated property damage of $4 billion. Table 1.1 shows the yearly losses due to

landslides in ten countries. Usually the weaker section or people at higher poverty level are

affected most as they are economically ill equipped in terms of resources to cope up with the

disruption of life due to this natural hazard. The economic losses due to landslides are twofold:

Direct costs: Repair, replacement, or maintenance resulting from damage to property or

infrastructure due to landslides. Indirect costs: Loss of productivity and revenues, reduced land

value, loss of tax revenues, landslide mitigation measures, adverse effect on water

quality/sedimentation/ siltation of reservoirs, loss of human or animal productivity because of

injury/trauma and secondary effects, such as landslide-caused flooding.

Landslide classification systems

The factors can be used and have been used to classify landslides are: Material(rock, soil

lithology, structure, geotechnical properties), geomorphic attributes (weathering, slope form),

landslide geometry (depth, length, height etc.), type of movement (fall, slide, flow etc.); Climate

(tropical, temperate, periglacial etc), water (dry, wet, saturated), speed of movement (very slow,

slow etc.) and triggering mechanism (earthquake, rainfall etc.).

Therefore, numerous approaches to classification of slope movements have been made,

concerning: type of movement, material, velocity, morphometric parameters, amount of water

involved, velocity, climate, etc. The most important classifications will be discussed briefly.

Sharpe (1938) presents a classification using type of movement (slip and flow), kind of material

(earth or rock) and the role of water/ice as main factors, while the speed of the movement is a

secondary parameter (Table 1).

Table 1: Classification system by Sharpe (1938)

Page 3 of 11

European Journal of Business &

Social Sciences

Available at https://ejbss.org/

ISSN: 2235-767X

Volume 07 Issue 05

May 2019

Available online: https://ejbss.org/ P a g e | 1586

The continuum of slope movements towards the transportation of solids mainly by water

(fluvial transportation) or by ice (glacial transportation) is clearly shown in the setup of the

classification. Hutchinson (1968, 1988) uses type of movement and morphology, which enables

for a classification based only on field observation or the evaluation of landslides by means of on

aerial photography. This classification also makes a practical use of the classification of Crozier

(1986). He uses threshold value of morphometric criteria (width, depth, length, dilatation, etc.) to

define different types of landslides (Table 2).

Table 2: The classification according to Hutchinson (1988)

Falls

Falls are sudden movements of loads of soil, debris, and rock that break away from

slopes and cliffs. Falls landslides occur as a result of mechanical weathering, earthquakes, and

force of gravity.

Slides

This is a kind of mass movement whereby the sliding material breakaways from

underlying stable material. The kinds of slides experienced during this type of landslide