Karst topography is a rugged landscape formed by the dissolution of soluble bedrock, primarily limestone, due to chemical weathering processes involving mildly acidic water. Essential conditions for karst formation include the presence of soluble rock, moderate rainfall, and groundwater movement through the rock. Key features of karst regions include sinkholes, uvalas, poljes, and various types of underground drainage systems and caves.

1. Karst topography

2. It is a typical rugged landscape shaped by
the dissolution of a layer or layers of soluble
bedrock, usually carbonate rock such as
limestone or dolomite.
 The term comes from the narrow strip of limestone
plateau in JUGOSLAVIA and adjacent portions of
ITALY bordering the Adriatic Sea.
 Notable karst areas are in regions where
LIMESTONE underlie the surface, although in
some localities the rocks are DOLOMITES or
DOLOMITIC LIMESTONE.
Topography developed due to the action of
ground-water is known as
Karst Topography.

3. Conditions essential to full development of Karst:
 They must be present at or near the surface a soluble
rock, preferably limestone suitable host rock.
 This soluble rock should be dense, highly jointed, and
preferably thinly bedded Permeable
 Existence of entrenched valleys below uplands
underlain by soluble and well-jointed rocks
ready downward movement of groundwater through
the rock
 At least moderate rainfall humid climate

4. Formation of Karst Topography:
Karst topography is a product of CHEMICAL WEATHERING.
Karst landforms are generally the result of mildly acidic water acting
on soluble bedrock such as limestone or dolostone in the following
way:
 The carbonic acid that causes these features is formed as rain
passes through the atmosphere picking up CO2, which dissolves in
the water. H2O+CO2 H2CO3
 Once the rain reaches the ground, it may pass through soil that
may provide further CO2 to form a weak carbonic acid solution.
Recent studies of sulfates, in karst waters, suggests sulfuric
acid and hydrosulfuric acid may also play an important role in karst
formation.

5.  This mildly
acidic water begins to
dissolve the surface
along with any fractures
or bedding planes in the
limestone bedrock.
 Over time, these
fractures enlarge as the
bedrock continues to
dissolve.
 Openings in the rock increase in size,
an underground drainage system begins to develop, allowing more
water to pass through the area, and accelerating the formation of
underground karst features.

6. SINKHOLE: Most common and widespread topographic form in
a karst terrain.
It is a depression in the limestone, which may be several meters
in diameter.
Most common form is funnel-shaped and broadly open upward.
Sinkhole:
Solution sinks (Dolines)
Developed slowly downward by
solution beneath a soil mantle without
physical disturbance of the rock. More
common than collapse sinks.
Collapse sinks
Produced by collapse of rock
above an underground void;
steep-sided, rocky & abruptly
descending forms.
Features characteristic of Karst region:

7. TERRA ROSSA: Surface and near-surface solution by
descending groundwater usually leaves a residue of a red,
clayey soil mantling the surface and extending down into
opened joints.
It is characteristically present on gentle slopes, may vary in
thickness from a few-many feet, even may mask the rock
surface completely.
It resembles in appearance the lateritic soil of the tropics, if
indeed it is not a species of it.
LAPIES: The leaching action of ground water as it
passes through the limestone region, produces a
highly rugged topography. The ground water may
enlarge the joints of the limestone into a conjugate
pattern of clefts and ridges, together called lapies
surface or limestone pavement.
KARST VALLEY: A very deep
valley, formed by the solution
process.

8. SOLUTION PANS: Variant of doline, much
shallower and may embrace a much larger
area.
SINKHOLE PONDS/KARST LAKES: When
doline become clogged with in swashed clay to
such an extent that they will hold water above
the regional water table.
KARST WINDOW: Special type of collapse
sinkhole applied to an unroofed portion of an
underground stream course through which may be
seen a stream which flows out of a cavern at one
side, across an open space, and into a cavern at
the opposite side. .
UVALA: A very large elongated depression
resulting from collapse of extensive roof
sections over underground water courses.
There is confusion in its usage. Sometimes it
means to Compound sinkhole also that formed
by convergence of two or more sink-holes.

9. POLJE: Larger depressions in the landscape(covering
tens of square kms)are known as poljes and are
characterized by steep sides and flat floors.
If the water -table is high enough lakes may form and
they are known as polje lakes.
HUMS/PAPINO HILLS: Small residual hills found on
the floors of Polje.
NATURAL BRIDGES: The remnant of the roof of a
natural tunnel or subterranean cut off.
BLIND VALLEYS: Valleys that lead into a hill side
or gradually lose the characteristics of a valley as the
water from their streams is lost to sub-surface
channels.

10. CAVERN/CAVE: A natural subterranean
runway void with their roof intact; may be
simple in plan or have complex
ramifications,may extend vertically or
horizontally and may occupy one or more
levels.
DRIPSTONE:
( Forms
developed by
water
dripping
from the
cavern
ceiling)
STALACTITES:
Downward-
extending
STALACMITES:
Upward-growing
COLUMNS &
PILLARS: Produced
when the preceding
forms grow together

11. Karst Cycle:
Consists four stages--
 Youthful Stage Characterise pogressive expansion of
the underground drainage.
 Mature Stage Displays lakes, uvalas and caverns.
 Late Maturity Stage Shows decline of karst features.
 Old Stage Reveals the reappearance of streams and
entrenched valleys on the surface.