Saltwater Intrusion in coastal areas of South 24 parganas , West Bengal

1. Characteristics of Salt Water Intrusion (South24
Parganas, West Bengal)
BY:
Aniket Singh(1758030)
Shubham(1758041)
Anubhav Anand(1758055)
Shiv Shankar Kumar(1758060)
Prince Kumar(1758062)
DEPT: Civil Engineering
UNDER THE GUIDANCE OF:
Prof: Rajshree Lodh

2. Preview
1.INTRODUCTION
I.)Definition
II.)Causes of saline water intrusion
III.)Effects of salt water intrusion
2.MODELLING SALTWATER INTRUSION
3.LITERATURE REVIEW
4.PRESENT STUDY AREA
I.)Introduction
II.)problem identification
III.)methodology
5.CONCLUSION AND FUTURE PREDICATION
6. REFERENCES

3. I.)Definition :
What is salt water intrusion ?
• Saltwater intrusion is the " movement of saline water into freshwater aquifers", which can
lead to groundwater quality degradation,including drinking water sources, and
other consequences.Saltwater intrusion can naturally occur in coastalaquifers, owing to the
hydraulic connection between groundwater and seawater.
• Salt water intrusion is driven by both
natural & anthropogenic pressures.

4. II.)Causes Of SalineWater Intrusion :
• Groundwater extraction
• Canals and Drainage networks
• Greater specific gravity of seawater than fresh water
density of fresh water =1 g/cm3
density of sea water =1.025 g/cm3(approx)

5. EFFECT OF SALT WATERINTRUSION :
• Agriculture production
• Water quality
• Ecological health of streams
• Human health

6. 2.Modelling of Saltwater
Intrusion
• A natural process that occurs in virtually all coastal aquifers.
• Define as movement of seawater inland into fresh
groundwater aquifers, as a result of
• Higher seawater density than freshwater.
• Groundwater withdrawal in coastal areas.

7. 2.1 Modelling of saltwaterintrusion
• Modellings are basically the numerical methods that
can simulate and predict the saltwater intrusion and
assess the impact on coastal aquifers.
• Field surveys can only reveal the present state of
seawater intrusion but can not make impact
assessment and prediction into the future,
• Numerical modelling tools are useful to understand
and predict seawater intrusion.

8. 2.2 Most popular models for
seawater intrusion
Model employed to simulate the seawater intrusion in coastal aquifers are
• Sutra
• Seawater
• HST3D
• FEFLOW
these models are very sensitive with respect to changes in hydraulic conductivity
and recharge.
And also sensitive to changes in porosity, anisotropy and dispersivity.

9. 3. Literature Review
• Saltwater intrusion in River Pearl.
• Method used to determine
• Water Supply strategies to withdraw freshwater
• Salt Water Intrusion in Changjiang Estuary
• Model used 3 Dimensionalnumerical method
• Fresh water withdrawal between the tides.
• Numerical modelling of saltwater intrusion in the Godavari Delta.
• Numerical Simulation and 2D finite element model.
• Result of the study

10. • A study on Saltwater intrusion in the coastal hard rock aquifer of South India.
• Na+>Ca2+>Mg2+>K+
• Cl->HCO3->SO4 2->H4SiO4>NO3->PO4->F-
• Dominant Factors
• Modelling and control of saltwater intrusion in a coastal aquifers in Andhra Pradesh,
India
• Period of 2 years
• Results of the study
• Tracing the evidence of Saltwater Intrusion in the coastal aquifers of Adhirapattinam,
India
• Low value of bicarbonate indicated the aquifers are fully soaked by seawater.
• Deteriorated groundwater

11. 4. Present Study Area
• Introduction
• South 24 Pragans, Kolkata, India
• Affected by the other districts as well.
• Groundwater Basin located lower GangaBasin.
• Indication of the saltwater Intrusion
• Problem Identification
• Main Sources are wells and bore wells.
• Major reason of the saltwater intrusion in the state.
• Absence of safe drinking water

12. Methodology
• Implication of the methods to stop the saltwater intrusion with urgency.
• Basic methods to stop intrusion is mostly affective.
• Reduction in pumping rate
• Rearrangement of Pumping walls.
• Artificial recharge and rainwater harvesting
• Injection and abstraction walls
• Construction of sub surface barriers.
• Groundwater monitoring network.

13. 5.CONCLUSIONS
• It has been found that South 24 Parganas is already saline prone area. In the
coming days due to the decadal growth of population and erratic rainfall, the
groundwater will be deteriorated so much by seawater intrusion that it will be
unfit for drinking water, irrigation purposes, and industrial use.
• Artificial recharge possibilities must be examined in this area to refill the over
pumped portions of the aquifer so as to reduce the effect of contamination.
• In reality, it is very difficult and very costly to re-establish the previous natural
conditions. Public should be awaked about water resources to raise the efficiency
of overall water use to the maximum limit.
• The efficient irrigation systemsshould be used or be madder available to the
farmers.
• Salt tolerant and drought resistantcrop varieties be developed and made
available to the local farmers to reduce pressure on the freshwatersources in the
study area

14. 5.1 Predicting the future Saltwater
Intrusion and Groundwater Head
• There is no quick measure to eradicate seawater intrusion. It can only be slowly
reduced with the hope of the state of the groundwater goes backward rather
than forward.
• We studied all the data available to us through sources and combinely tried to
predict the future seawater intrusion in the groundwater through a graph.
• we have assumed some parameters like soil property, Rainfall variation, previous
seawater intrusion, etc.
• The Graph is drawn below for the groundwater head.

15. PREDICTED GROUNDWATER HEAD FOR THE
FUTURE YEARS
∗ MSL means Mean Sea Level

16. 6.REFERNCES
• Wavelet analysis of the dynamic characteristics of saltwater intrusion – A case
study in the Pearl River Estuary of China.
• Numerical modeling of salt-water intrusion due to human activities and sea-level
change in the Godavari Delta, India by A. GHOSH BOBBA
https://doi.org/10.1080/02626660209493023
• A study on the status of saltwater intrusion in the coastal hard rock aquifer of
South India. By C. Singaraja, S. Chidambaram, P. Anandhan, M. V. Prasanna, C.
Thivya & R.
• The present study of seawater intrusion in the coastal aquifers of India
https://doi.org/10.1016/j.hydres.2020.06.001
• Modern problem and identification http://s24pgs.gov.in/s24p/
• Pumps and pumping system - Bureau of Energy .http s://beeindia.gov.i
• Groundwater and Streamflow Information Program https://www.usgs.gov/
• Assessmentof the possibility of saltwater intrusion in the central Godavari delta
region, Southern India (LaguduSurinaidu, Velidi V. S. Gurunadha Rao,
JampaniMahesh)(2014)