Landslides occur when several factors converge, including heavy rainfall, earthquakes, volcanic eruptions, construction activities, and deforestation. They can cause significant damage by destroying infrastructure like roads, buildings, and bridges. Some high-risk areas include mountainous regions and coastal cliffs. To reduce landslide risk, proper drainage systems and replanting vegetation on slopes is recommended. During a landslide, it is important to seek high ground and avoid further endangering rescue workers.

1. SUBMITTED TO:-
PROF. ARCHEE VERMA
SUBMITTED BY:-
ANAND SWAROOP JAICHANDRAN
4TH YEAR SEM-VIII
M.I.T.S. GWALIOR (M.P.)

2.  Landslides are defined as mass movement of rock, debris or earth down a slope and
have come to include broad range of motions whereby falling, sliding and flowing
under the influence of gravity dislodges earth material.
 Take place in conjunction with
I. Earthquakes
II. Floods/ prolonged rainfall
III. Volcanoes
 Hilly terrain is highly sensitive to landslides – Himalayas and Western Ghats
 Landslides can do great damage and change the land very quickly.
 If a slippery material is present below soil then soil can become heavy with rainwater
and prone to landslide. It is a downward or outward movement of soil, rock,
vegetation due to gradient. This movement can be fall, flow, slide, spread or topple.
Landslides occur usually at steep slopes but these may occur in areas with low slope
gradient.

4.  LATERAL SPREAD- Spread is defined as an extension
of a cohesive soil or rock mass combined with a
general subsidence of the fractured mass of cohesive
material into softer underlying material.
 ROTATIONAL SLIDES- It move along a surface of
rupture that is curved and concave.
 TRANSITIONAL SPREAD- In translational slides the
mass displaces along a planar or undulating surface of
rupture, sliding out over the original ground surface.
 CREEP- It is spatially continuous movement in which
surfaces of shear are short-lived, closely spaced, and
usually not preserved its speed is extremely slow.
 ROCK FLOW- Extremely rapid, massive, flow like
motion of fragmented rock from a large rock.

5. In the following table shows a schematic landslide classification adopting the classification of Varnes
1978 and taking into account the modifications made by Cruden and Varnes, in 1996. Some integration
has been made by using the definitions of Hutchinson (1988) and Hungr et al. 2001

6. A. Natural Factors
 Gravity – works more effectively on steeper slopes
 Geological factors – weak, sensitive or weathered materials
 Heavy and prolonged rainfall – rapid rise in water level and saturation
 Earthquakes – plate tectonic moves the soil that covers it also moves
 Forest fire – causes erosion and induce floods and landslides
 Volcanoes – kill vegetation over extensive area and spreads volcanic rocks,
subsequent
 rainy season will trigger landslides
 Waves – can erode the beach or the toe of a bluff, cutting into slope Freezing
and Thawing
Landslides occurs when several factors converge:-

7. B. ANTHROPOGENIC FACTORS
 Inappropriate drainage system – natural drainage lines on slopes are
blocked by terracing/ contour bounding
 Cutting and deep excavations on slopes for buildings, roads, canals and
mining – modification of natural slopes, blocking of surface drainage,
loading of critical slopes and withdrawal to toe support
 Change in slope/ land use pattern, deforestation, settlements, agricultural
practices on steep slope.
 C. HUMAN ACTIVITIES
 Deforestation, Cultivation and Construction when destabilize the already
fragile slopes.
 Vibrations from machinery or traffic, blasting, Construction.
 In shallow soils, the removal of deep-rooted vegetation that binds
colluviums to bedrock.
Landslides occurs when several factors converge:-

8. Landslides destroys everything and anything that comes in their path.
•Roads
•Rail lines
•Lines of communication
•Settlements
•River flows/ Damming
•Agricultural production
•Land area
•Flooding
•Water availability, quality and quantity
•Flora and Fauna
Fatalities depends on the place and time of occurrence.
Estimated casualties per year, world-wide: 600 - 1000 persons.
HOTSPOTS
• Anywhere with steep slopes and weathering
•High mountain ranges, sheer cliffs, and steep sided river valleys
•Where volcanoes erupt and along coasts

9. EXAMPLE
S

10. •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, and ancillary structures such as decks and
patios tilting and/or moving relative to the house.
•Sticking doors and windows, and visible open spaces.
•Broken water lines and other underground utilities.
•Leaning telephone poles, trees, retaining walls or fences.
•Sunken or dropped-down road beds.
•Rapid increase in a stream or creek water levels, possibly accompanied by
increased turbidity (soil content).
•Sudden decrease in creek water levels even though rain is still falling or just
recently stopped.

11. Prevent landslides and neighborhood drainage problems in
landslide prone areas:-
•Water is the most common cause of unstable slopes, landslides, and erosion. Check your
home's drainage system. Maintaining the drainage system on private property is the
owner's responsibility. Make sure your drainage system directs water away from your
foundation and not on to your neighbor's property.
•Never discharge water over the side of a steep hill.
•Clean your gutters and downspouts. Check your gutters once a week during fall and
winter. Just one wind or rainstorm can clog a well-flowing drainage system.
•Clean your gutters and downspouts. Check your gutters once a week during fall and
winter. Just one wind or rainstorm can clog a well-flowing drainage system.
•In general, trees and plants with strong root structures help prevent soil erosion but do
not prevent landslides
•Never block any part of the city's drainage system. Do not put leaves, dirt, grass
clippings, or any materials in ditches, culverts, or drains. Doing so can cause flooding. It
is against the law to dump any material into the drainage system.

12. MEASURES TO REDUCE THE CHANCE OF LANDSLIDES:
•Vegetation cover protects land from landslides and soil erosion. Therefore efforts should be
made to maintain greenery particularly on slopes. Provisions should be made at community
level to prevent people from excavating, removing materials from the soil or cutting trees.
•Trees should be planted on slopes and slopes base to prevent erosion. Record of erosion,
landslide masses and falling rocks should be maintained.
•During construction a building on a slope design that suits the natural slope should be
adopted.
•Vegetation and trees should not be removed while constructing. Natural streams or drainage
paths should not be constructed during construction. Surface water should be diverted
towards the natural galley enabling water to quickly drain away from the slope.
•Quickly move out of path of the landslide or debris flow.
•If inside a building, stay inside and take cover under a desk, table or other sturdy
furniture.
•If escape is not possible, curl into tight ball and protect your head.
PRECAUTIONS DURING LANDSLIDE:

13. PRECAUTIONS DURING LANDSLIDE:
•Check for injured and trapped persons, without entering the slide and direct and
assist rescuers.
•Help vulnerable group persons in neighbourhood for emergency assistance.
•Listen to local radio or television station.
•Watch for flooding, which may occur after a landslide or debris flow.
•Look for and report damaged utility lines to authorities.
•Replant damaged ground as soon as possible since erosion caused can lead to flash
flooding.
•Seek professional advice for evaluation of landslide hazard and designing corrective
techniques to reduce landslide risk.
LANDSLIDE IN HILLY AREADEMOLISHED ROAD

14. LANDSLIDE BLOCKING THE HIGHWAY DEMOLISHED HOUSES BY LANDSLIDE

15. •Western Ghats
– A: Kerala: small catchment
– B: Nilgiri: transportation corridor
• Himalayas:
– C: Okhimath: high Himalaya, large area
– D: Darjeeling: middle Himalaya, watershed .

16. •Aruvikkal catchment : 9.5 km2
•Sub catchment of Tikovil River
•History of debris flows during the
monsoons
•Dominant rock type: Charnokites
•UNU‐ITC – CESS debris flow
research catchment
•Rubber plantation area
•Clear relation landuse ‐landslides

18. • Kurseong in the Darjeeling
district
• Elevations in the study area
vary from 236 m to 2189 m
• Annual precipitation in the
area varies from 2000 to 5000
mm
• metamorphic rocks of the
Himalayan Fold‐Thrust Belt
(FTB)
• foreland molasse basin in the
south
• Main Boundary Fault (MBT)
• Main Central Thrust

19. • Most landslides are structurally
controlled
(a) A deep‐seated rock wedge
(W_Fol x J2) within Daling
metasediments,
(b) Plane failure (P_Fol) along
foliation surface (Fol) in
sheared phyllonitic rocks
(c) Toppling (T_J1) caused by
steep‐dipping SW‐dipping
joint plane (J1) within
quartzo‐feldspathic gneiss
Retrogression of a deep‐seated
rock wedge slide.

20. EXAMPLES

21. CASUALTIES

22. “A kind gesture can reach a wound that only compassion can heal.”