This document discusses hill slope erosion and its consequences. It defines slope and erosion, and introduces hill slope erosion as erosion that occurs on slopes. The key elements of a hill slope profile are then described: summital convexity, free face, rectilinear, and concave elements. Processes that cause hill slope erosion are explained, like soil creep, overland flow, rainsplash, throughflow, and rilling. Causes of erosion are noted, both natural factors like climate and vegetation as well as human factors like deforestation. Consequences include loss of topsoil, damage to infrastructure and homes, and blocked roads. Measures to control erosion are outlined, such as afforestation, controlling grazing, and steps

1. Topic:- Hill Slope Erosion
& Its Consequences
Presented By:- Barsha Changmai
Roll no.-12
Centre for Studies in
Geography
MA 1st Semester
Dibrugarh University

2. Slope
Slope is upward or downward
inclination of surface between hill
and valleys and formed most
significant aspect of landform
assemblages.
Erosion
Erosion is the action of surface
processes ( such as water flow
or wind) that remove soil, rock
or dissolve material from one
location and then transport it
away to another location
Introduction

3. Hill slope erosion
The erosion which occurs
in hill slope is known as
hill slope erosion. It is an
important component of
the complex landscape
that forms a drainage.

4. • The entire slope profile is
punctuated by the presents of
convexity, concavity, rectilinearity
and free face. This distinctive
segments of slope profile are called
slope elements or slope segments.
• It is not always necessary that all
the slope profile will comprise all the
four elements but an ideal hill slope
profile is that which consist of all the
four elements.
• In case of hill slope the existence
of free face (cliff) element depends
on the presents of resistant strata.
Element of hill slope erosion

5. 1. Summital convexity :The convex segment is found at the hill crest (hill
top) and this element is called summital convexity.
2. Free face: Free face element of hill slope represents wall-like precipitous
slope of bare rocks and is devoid of any debris. The slope is so steep and
precipitous that no weathered materials can rest on it.
3. Rectilinear element: The straight or linear segment of hill slope profile
between upper free face and lower concave element is called rectilinear
element.
4. Concave element: The basal segment of an ideal hill slope profile is
always characterised by concave element the slope angle decreases as
the segment of basal concavity increases(in length).

6. HILL SLOPE PROCESS AND EROSION
Hill slope process includes those erosion process which modify slope form
such as creep, overland flow rain splash, rain wash, through flow, rill and
gully erosion etc.
1. Soil creep:
• It is an transportation process which facilitates mass but slow movement of
moistened and loosened soil soaked with water which acts as lubricator.
• It plays major role in rounding the hill slope mainly crystal rounding and in
giving convex slope from hill to crest.

7. 2.Overland Flow
• It is also known as
surface runoff
• It is an effective
agent and process
of slope erosion
and slope
modification.

8. 3 . Rainsplash
• it is a erosion of loose
superficial matters by the
direct impact of falling
raindrops .
• The intensity of the
splash erosion depends
on the kinetic energy of
falling raindrops.
• Rainsplash becomes
more effective on
vegetation free slopes
where falling raindrops
directly hit the surface
with full kinetic energy.

9. 4.Throughflow
• It is also known as interflow.
• It refers to lateral flow of
infiltrated water down the
slope below slope surface.
• It is effective on densely
vegetated slope because
because dense vegetation
allows maximum infiltration of
rainwater as falling rain drops
are intercepted by forest
canopy and thus rainwater
reaches the groundwater.

10. 4. Rilling
• It is also known as rill and gully
erosion.
• it is significant mechanism of
slope erosion.
• Riling refers to superficial loose
materials as well as rock beds
through concentrated linear flow of
water known as rill.
• Riling is more effective on
vegetation free steep slopes.
• The pattern of rill depends on the
steepness of slopes.
• The intensity of rill erosion
increases down slope.

11. CAUSES OF HILLSLOPE EROSION
Natural Factors
 Climate.
 Vegetation Cover
 Topography
 Tectonic activity
Man Made Factors
 Deforestation
 Shifting cultivation
 Buildings of Road
 Construction of Dams
 Urban Development
Mining and exploration activities

12. CONSEQUENCES OF HILLSLOPE
EROSION
1. Hillslope erosion removes valuable top soil which is the
most productive part of the soil profile for agricultural
purposes.
2. Many valuable trees falls.
3. House that are built along the hill are at risk of being
damaged and also people may die too
4. Animals that live at the hill are at risk for the loosing
homes.
5. Blocking of roads and railways.
6. It may cause production loses to open cast mines, rock
quarries etc.

13. MEASURES TO
CONTROL
HILL SLOPE EROSION
1. Afforestation.
2. Horticulture should be practised
instead of shifting cultivation.
3. Controlling over grazing in hill
slope.
4. By taking appropriate steps in
road, bridge and dam construction.
5. Installing silt fences.

14. Thank You