1. UNIVERSITY B.T. & EVENING COLLEGE
SEMINAR ON ENVIRONMENTAL SCIENCE
TOPIC– MASS MOVEMENT AN IMPORTANT GEOMORPHIC PROCESS
SUBMITTED BY-UPASAN ACHARYA ,M.sc.(GEO)
ROLL NO-02
B.Ed. SECTION
SESSION

2. WHAT IS MASS MOVE MENT?
The concept of mass movement or mass wasting was advocated by SHARPE in The transport also brings substantial changes on the crust of the earth and it therefore has been recognised as an important geomorphic process.
Mass movement is the downslope transfer of material through the direct action of gravity .The process can be rapid like landslide ,or slow as creep of soil down the gentle slope of gravity covered field.
So, it can be termed as---The movement of weathered material under the influence of gravity and with or without the influence of rainwater is called MASS MOVEMENT.

3. Factors responsible for mass movement
GRAVITY
SATURATION OF MATERIAL WITH WATER
VIBRATIONS FROM EARTHQUAKES
OVERSTEPPING OF SLOPE BY UNDERCUTTING
CONSTRUCTION OF CANALS & ROADS
STREAM EROSION
GLACIAL EROSION
WEATHERING
PRESSURE RELEASE

4. TYPES OF MASS MOVEMENT MASS MOVEMENT SUBSIDENCE SLOW FLOWAGE
RAPID FLOWAGE
LANDSLIDE

5. SLOW FLOWAGE SOIL CREEP TALUS CREEP ROCK CREEP ROCK-GLACIAL CREEP
SOLIFLUCTION

6. RAPID FLOWAGE
EARTH FLOW
MOD FLOW
DEBRIES AVALANCHE

7. LANDSLIDES
SLUMS
DEBRISE SLIDE
DEBRIES FALL
ROCK SLIDE
ROCK FALL

8. Types of mass movement in a frame

9. Description of some mass movements
SLUMP-A slipping of coherent rock material along the curved surface of a decline. Slumps involve a mass of soil or other material sliding along a curved surface (shaped like a spoon). It forms a small, crescent-shaped cliff, or abrupt scarp at the top end of the slope. There can be more than one scarp down the slope.

10. Picture of a slump

11. An Evidence of a slump

12. Diagram of a slump

13. LANDSLIDE- The downslope gravitational movement of a body of rock or earthmaterial is termed as landslides .It may be induced by natural agencies (e.g.,heavyrain,earthquake) or it may be caused by human interference with the slope stability.

14. Images of sikkim landslide after 18th sep,2011 earthquake

15. An evidence of a landslide

16. Satellite image shows landslides

17. CREEP-It is a long term process
CREEP-It is a long term process. The combination of small movements of soil or rock in different directions over time are directed by gravity gradually downslope. The steeper the slope, the faster the creep. The creep makes trees and shrubs curve to maintain their perpendicularity, and they can trigger landslides if they lose their root footing. This happens at a rate that is not noticeable to the naked eye.

18. FLOW-Movement of soil and regolith that more resembles fluid behavior is called a flow. These include avalanches, mudflows, debris flows, earth flow, lahars and sturzstroms. Water, air and ice are often involved in enabling fluidlike motion of the material.

19. DEBRIES SLIDE- The nearly free fall of earth debries from a vertical cliff is known as debries slide.It is mainly found along the banks of streams.

20. Diagram of debries slide

21. Factors responsible for landslide
DEFORESTRATION
VIBRATIONS FROM EARTHQUAKES
CONSTRUCTION OF CANALS & ROADS
CONSTRUCTION OF DAMS
UNPLANNED URBANIZATION IN HILLS
UNPLANNED AGRICULTARAL ACTIVITIES
UNPLANNED MINING ACTIVITIES
WEAK GEOLOGICAL FORMATION OF SLOPE
HEAVY RAINFALL
CLOUD BRUST

22. The trigger effect of landslide

23. LANDSLIDE-PRONE AREA
The most vulnerable regions are mainly in Jammu & Kashmir,Uttarakhand(Kedarnath,B -- adrinath, Gangotri,Y amunetri,uttarkashi etc),sub-Himalayan WestBengal(Darjeeling & Sikkim himalayas),North-East hilly regions.

24. Map shows landslide prone areas

25. THANK YOU