Karst aquifers are underground aquifers formed from the dissolution of soluble rocks like limestone, creating drainage systems with sinkholes and caves. Water flows through enlarged fractures and conduits in the limestone, making karst aquifers highly permeable but also vulnerable to pollution. The dissolution occurs when acidic water reacts with the rock, widening cracks over time and potentially forming underground rivers. Farming can be challenging in karst areas as rainwater flows directly into the ground through crevices rather than remaining as surface water. Keeping pollution out of karst aquifers requires responsible handling and disposal of potential contaminants by citizens in these areas.

1. KARST AQUIFERS
PRESENETED BY AQIB ALI NAICH (16MN40)

2. AQUIFER
• An aquifer is an underground layer of water-
bearing permeable rock, rock fractures or
unconsolidated materials (gravel, sand,
or silt). Groundwater can be extracted using a water
well.

3. INTRODUCTION
• Karst is a topography formed from the dissolution of soluble
rocks such as limestone, dolomite, and gypsum. It is
characterized by underground drainage systems
with sinkholes and caves.
• Karst aquifer is limestone ( or any other easily dissolved
rock) that has been partly dissolved so that some fractures
are enlarged into passages (called conduits) that carry the
ground water flow.
• A type of land formation, usually with many caves formed
through the dissolving of limestone by underground
drainage.

4. INTRODUCTION
Underground river cave

5. CHEMISTRY
• The development of karst occurs whenever acidic water
starts to break down the surface of bedrock near its cracks,
or bedding planes.
• As time goes on, these fractures will become wider, and
eventually a drainage system of some sort may start to
form underneath.
• The primary reaction sequence in limestone dissolution is
the following:
H2O + CO2 → H2CO3
CaCO3 + H2CO3 → Ca2+ +
2 HCO−
3

6. HYDROLOGY
• Farming in karst areas must take into account the lack
of surface water.
• The soils may be fertile enough, and rainfall may be
adequate, but rainwater quickly moves through the
crevices into the ground.

7. HOW KARST AQUIFER IS POLLUTED ?
• Karst aquifers are susceptible to pollution because runoff can
enter conduits through sinkholes without being filtered
through sand, gravel or even soil.
• To keep ground water safer to use, pollution must be kept
out of karst aquifer.
• Personal responsibility of all citizens living in karst areas,
especially handling or disposing of potential pollutants, is the
best remedy