Ingress of salinity in coastal area
P re p a re d B y : -
Patel Hardik P. (En No.110780106034)
Patel Dax S. (En No.110780106026)
Patel Sapana S. (EnNo.110780106011)
Patel Hiral J. (En No.110780106023)
Guided By:-
Prof .Mr Bhavik G Patel
Prof. Mr Utkarsh Nigam 1
Presentation Preview
Introduction
Problem
Objective
Literature
Methodology
Data collection and monitoring
Scope of work 2
Introduction
Salinity is the saltiness or dissolved salt content of a body of water.
Salinity is an important factor in determining many aspect of the
chemistry of natural water and biological process.
The “Salinity refers to the degree of saltiness of water or more
specifically the concentration of dissolved solids involved”
Seawater intrusion is the movement of seawater into fresh water
aquifers due to natural processes or human activities.
The amount of salinity in a given water is expressed as Total
Dissolved Solids (TDS) and specified either in terms of weight of
salts in solution or weight of salt per unit volume of water.
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Introduction
There are several different ways to measure salinity; the two
most frequently used analyses are described below :
Total Dissolved Solids (TDS) : TDS is a measure of all dissolved
substances in water, including organic and suspended particles that
can pass through a very small filter. TDS is measured in a
laboratory and reported as mg/lit.
Electrical Conductivity (EC) : The ability of an electric current to
pass through water is proportional to the amount of dissolved salts
in the water-specifically, the amount of charged ( ionic ) particles.
EC is a measure of the concentration of dissolved ions in water
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Seawater Intrusion
A natural process that occurs in
virtually all coastal aquifers.
Define as a movement of
seawater into inland fresh
groundwater aquifers, as a result
of
1. Higher seawater density than
fresh water
2. Ground water withdrawal in
coastal areas
This migration of seawater into
the freshwater aquifer is known
as seawater intrusion.
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The first physical
formulations of saltwater
intrusion were made by
W.Badon-Ghijben (1888,1889)
and A. Herzberz (19 01) thus
called the Ghyben-Herzberz
relation.
The Figure shows the
Ghyben-Herzberz relation.
Z= 40h
Ghyben-Herzberz Relation
The depth to the interface between freshwater and saltwater is
approximately 40times the height of the water table above sea level.
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Land move down Tectonic uplift
Sea level rise Change in
hydrological regime
Costal zone River & Estuaries
Human activates Countermeasures
Effects
Costal aquifers
Change in natural recharge: Precipitation evapotranspiration
Costal erosion Tidal effect
Back water effect Saline surface water
Ground water extraction Mining – gas oil sand
Salt water intrusion Salt damage crop Decrease ground water resources
Extraction saline groundwater Increase natural recharge Physical obstruction
Problem occurs due to sea water intrusion
Near costal area the crop fail problem is increase.
By salinity problem construction cost is also increase.
Irrigated land has become barren due to seawater intrusion.
Domestic water supply is difficult to manage by an individual.
An increase in TDS, Fluoride & Chloride contents has created many
human diseases.
Reduction in agricultural productions due to deterioration in ground
water quality. 8
Saltwater intrusion construction cost increase
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land has become barren due to seawater intrusion
increase in TDS, Fluoride & Chloride contents
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Literature
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1) Climate change and environmental problem in world
Climate is one of the more complex physical systems in nature, its
behavior being fundamentally non-linear and chaotic.
Author : Biplab Das
Dr.Aditya Bandyopadhyay Indian Institute of Engineering, Science
and Technology, Kolkata
Issue 6, December 2012
A ground water is the essential features of a natural hydro
geological system that uses the laws of considered as unsuitable for
irrigation and drinking purposes.
Literature
A preliminary survey of the coastal city-Bhavnagar was undertaken to
assess salinity ingress probed through groundwater quality.
2) Ingress of salinity in Bhavnagar City
Author: PRASHANT N. BHATT
JIGNASU P. MEHTA
HITENDRA J. JANI AND
S. KURUP
PP.. 312665- -313658, O
Jcutolyb e 2r0 200605
The quality of ground water in some of the areas was found high
saline and can not be used even for irrigation purpose.
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Literature
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Seawater intrusion is one of the most important environmental
problems that degrade groundwater resources
3) To study the control of seawater intrusion in coastal aquifers
Author: A.A. Javadi June 21 - 26, 2010
Computational Geomechanics Group,
College of Engineering
Seawater intrusion increases salt concentration in groundwater
which places limitations on its uses
This type control of seawater intrusion is very important to protect
groundwater resources from depletion.
Literature
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4) Salt water in costal aquifers
Costal area characterized by the interaction of land, sea and
atmosphere’ so management of all the interactive components in a
rational and comprehensive manner
Author: S.M Seth National institute of hydrology jay vigyan
bhavan
Roorkee - 247667
Quantitative understanding of the pattern of movement and
saline water and of the factor that influence these processes is
required to manage and protect the fresh water resources in the
costal regions
Literature
5) MANAGEMENT OF GROUNDWATER IN SALT WATER
INGRESS COASTAL AQUIFERS
Author : C. P. Kumar
National Institute of Hydrology
Roorkee – 247667 (Uttaranchal)
Schematic illustration of some of the modes of saltwater intrusion in
a multilayer, regional aquifer system caused by groundwater pumping
at wells. Saltwater moves into the unconfined aquifer from the ocean
and into the shallow part of the top confined aquifer from the major
bay.
Through the seawater intrusion has not yet assumed serious
magnitude, but in the coming years it may turn to be a major problem
if corrective measures are not initiated at this stage 15
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Junagadh district lies between 21º 10' and 21º 40' north latitude and
70º 18' and 71º 15' west longitude region, in the state of Gujarat India,
known as Kathiawar or Saurashtra. This district is bounded by the Rajkot
district in North Amreli district in East, Arabian Sea in Southand by the
Arabian Sea and Porbandar district in the West. Total geographical area
of Junagadh district is 6,996,011.21 hectares
My study area cover Simar village is located 15 km SE from Rajgath
& on the coast of Arabian sea.
Topographical flat with gentle eastward slope towards sea.
Study Area Detail
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Study Area Detail
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In the coastal area of Saurashtra, which is 765 km. long, the issue of
salinity has been observed due to natural factors of salinity of ocean
water and also due to human interference in the natural balance, a total of
700120 hector area, 534 villages, 1079733 persons and 32750 wells were
affected. The economical condition of this area was adversely affected
and issues of migration of people had also taken place due to
deterioration of underground water due to salinity and adverse effect on
agricultural products and industries based on agricultural due to
excessive lifting of water by the farmers. This study will try to check
improvement of water quality due construction of various recharge
structure by the government.
Need Of Study
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Objectives
1. To study the phenomena of salinity ingress in Rajgath taluka
2. To produce contour map of reduced water level, TDS & sea water
intrusion ratio indicator map by use of surfer.
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METHODOLOGY
Data
1.TDS DATA 2.Reduced Water level Data
3. SEA WATER INTRUSION RATIO INDICATOR
USE OF SURFER SOFTWARE
RUN
CONCLUSION
Methodology
Data collection and monitoring
A great variety of data is required for integrated water management
studies.
The types of data required for groundwater studies in coastal and
deltaic areas, where saltwater intrusion plays a role, are given below.
1. The subsoil
The geologic structure of the subsoil
Hydrological structure of the subsoil
2. The natural input
Climate data, in particular precipitation and evapotranspiration
Natural recharge
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4. Groundwater quality
Chemical and isotopic composition, in particular salinity, but also any
other contamination
Sources of groundwater pollution
5. Surface water
Natural outflow
Availability and quality of surface water for artificial recharge
7. Water demands, at present and estimates for the future
9. Relative sea level rise.
Cont….
3. Water levels
Groundwater levels and surface water level
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Use Of Surfer Software
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Use Of Surfer Software
1.To Create XYZ data file with use of longitude, latitude & reduced
water level
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Use Of Surfer Software
2.To Create a grid file [.GRD] from the XYZ data file using the grid
data command
3. To Create contour map by use of grid file
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Use Of Surfer Software
4. To create a Post map show data locations on a map
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Use Of Surfer Software
5. To create Vector map in this vector map an arrow represents a
vector’s direction and magnitude at a grid node, the length of the arrow
represents the magnitude of the slope
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TDS contour map of Rajkot (may 1991)
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TDS wireframe map may 1991
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Data Collection
1. Primary situation of salinity ingress
2. Salinity ingress & affected area in Rajgath
3. Average rainfall in Rajgath
4. Water level data of different wells
5. TDS data of different wells
6. Latitude, Longitude & RL of different wells
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Ingress of salinity (km) in Rajgath (1977-2010)
7.5 8.5
7.75 7.15
4.85 4.96
6.41
5.28 5.27 5.8
4.57 5.42
1977 1988 2000 2002 2003 2004 2005 2006 2007 2008 2009 2010
Salin
ity
ingr
ess
(km
)
Year
32
Area Affected By Salinity In Rajgath (1977-2010)
0
5000
10000
15000
20000
25000
30000
Aff
ecte
d a
rea
(h
ec)
33
Average rainfall (ml) in Rajgath
0
200
400
600
800
1000
1200
1400
1600
Avg
rai
nfa
ll (m
l)
Year
Details of Rainfall (ml) In Una
0
200
400
600
800
1000
1200
1400
1600
Avg
rai
nfa
ll (m
l)
Year
Details of Rainfall (ml) In Una
34
Salinity ingress in affected area
0
1
2
3
4
5
6
7
8
9
0
5000
10000
15000
20000
25000
300001
97
1
19
73
19
75
19
77
19
88
19
93
19
94
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
20
07
20
08
20
09
Salin
ity
ingr
ess
(km
)
Aff
ecte
d a
rea
(hec
)
Salinity Ingress V/s Affected area In Rajgadh
Affected Area Salinity Ingress (km)
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Conclusion 1. It has been observed the study area having good aquifer to absorb
ground water.
2. Because of annual recharge, water table is increased which is
responsible for decreasing TDS
3. By using golden surfer software we prepared wireframe and contour
map of our study area which is affected by salinity.
3. It has been observed that pre monsoon and post monsoon data of the
TDS value is more than the desirable value which are alarming for
the health.
Scope of of work
Increase in salt contents is related to a series of factors such as the
permeability of the soils, drainage facilities, quantity of water
which is applied, crops in the area and climate in general.
Intrusion of saline water in coastal environments occurs all over the
world.
In places where groundwater is being pumped from aquifers that are in
hydraulic connection with the sea, the induced hydraulic gradients
may cause the migration of salt-water from the sea towards the well.
Investigation of saline intrusion is extremely important because it
constitutes probably the commonest of all pollutants in fresh water.
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Thank you for your
attention
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