The document discusses different aspects of groundwater, including: 1. It describes the different zones of groundwater - the zone of aeration near the surface and the saturated zone below. 2. Sources of groundwater are discussed, including wells, springs, infiltration galleries, and karez. Wells can be open dug wells or tube wells, with open wells having larger diameters but lower yields. 3. The uses of groundwater are listed as agriculture, domestic, industrial, cooling, and providing village water supplies.

1. Unit-3
Ground Water
Mr. Dipesh Rajput
Lecturer in Civil Engineering
Dr. S. & S. S. Ghandhy College of Engg. & Tech., Surat
Email: dipesh_rajput2000@yahoo.com
Water Resources
Management (3340604)
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Lecture-2

2.  Out lines
1. Uses of water
2. Limitations of use of ground water
3. Zones of ground water
4. Sources of ground water
 Wells
 Springs
 Infiltration galleries
 karez
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3.  Uses of Ground Water
 The main uses of ground water are:
1. Agriculture use
2. Domestic use
3. Industrial use
4. Air conditioning or cooling plant
5. To get water through bore well in villages
6. To get good quality of water
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4.  Limitations of use of Ground Water
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5.  Zones of Ground Water
The subsurface water may be divided into the following two zones:
a) Zone of aeration
b) Zone of saturation
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6. a) Zone of Aeration
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 Fig. shows the classification of groundwater.
 The soil water zone is adjacent to the ground surface.
 The intermediate zone is between the lower edge of the
soil water zone and the upper edge of the capillary zone.
 The capillary zone extends from the bottom edge of the
intermediate zone to the upper edge of the saturated
zone.
 The thickness of the capillary zone depends on the
properties of the soil and also on the homogeneity of the
soil.
 The depth of capillary zone is varying from few
centimeters to few meters. In capillary zone, all the pores
are field up with water.

7. a) Zone of Aeration Conti….
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 However, we cannot draw water by inserting a well
up to that depth.
 This is because of the negative pressure developed
at this zone due to surface tension effect.
 Groundwater zone starts from the bottom edge of
the capillary zone.
 In this zone, all the pores of the soil matrix are
filled with water.
 This zone is also known as zone of saturation.
 The top surface of the zone of saturation or
groundwater is known as phreatic surface.
 This phreatic surface is also known as water table.

8.  The degree of saturation for the soil below the water table is
equal to 1, i.e. the soil is fully saturated.
 As a groundwater hydrologist, we are primarily interested for
the water below the groundwater table, i.e. the water
available in the zone of saturation.
 For the soil above the water table, the degree of saturation of
the soil is varying between 0 and 1 .
 However, the degree of saturation will never be 0 due of the
presence of hygroscopic water.
 The hygroscopic water is the water that held tightly on the
surface of the soil colloidal particle.
 Hygroscopic water can be removed from the soil by oven
drying.
 Fig. shows the moisture distribution in soil column.
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b) Zone of Saturation

9.  The water table acts as a boundary between saturated
zone and unsaturated zone.
 The soil matrix is fully saturated below the water
table. At the same time, the soil just above the water
table is also saturated due to the capillary effect.
 The depth of capillary rise may be from few
centimeters to few meters.
 A suggested by Silin Bekchurin (1958), capillary rise
may be around 2-5 cm in case of course sand, may be
around 12-35 cm in case of sand, around 35-70 cm in
case of fine sand, around 70-150 cm in case of silt and
around 2-4 m and more in case of clay soil. 9
b) Zone of Saturation Conti….

10.  Fig.1.4 shows the actual and approximate
distribution of the moisture content.
 The actual distribution can be approximate by a
step function which is necessary to approximate
the elevation of the groundwater table.
 The step defines the depth of the capillary
rise, hc.
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b) Zone of Saturation Conti….

11.  Sources of Ground Water
 The following are the important sources of ground water
1. Wells
2. Springs
3. Infiltration galleries
4. Karez
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12. 1. Well
 A water well is shaft, usually vertical, excavated
in the earth for bringing ground water to the
surface.
 Water wells may be classified as:
a. Open well or Dug wells
b. Tube wells
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13. a) Open well
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 Open wells are the wells which have
comparatively large diameters but low yields (or
discharges) and are not very deep.
 The diameters of the open wells usually very from
1m to 10 m.
 The yield of such wells in most of the cases is
about 20 m³/hour or less.
 However, a properly constructed open well
penetrating a permeable aquifer can yield 100 to
300 m3/hour.

14. a) Open well Conti…….
 The depth of open wells may generally range from 2 to 20 m.
 Since, these wells are usually constructed by digging, these are also
known as dug wells.
 The walls of the open wells may be built of brick or stone or precast
concrete rings.
 The thickness generally varies from 0.5 m to 0.75 m depending upon the
depth of the well.
 Open wells Based on depth
a. Shallow well b. Deep well
 Open wells Based on type of wall
1. Kachha well 2. Well with impervious lining 3. Well with Pervious lining
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Fig. Shallow & Deep Well

16.  Shallow wells are those which rest in the top water bearing strata and draw their
supplies from the surrounding material.
 Deep well is a well which rest on impervious layer (mota layer) and draw their supplies
from the pervious formation lying below the mota layer.
 The impervious layer is generally known as a mota layer and it is a layer of clay, cemented
sand, kankar or other hard materials.
 The mota layer gives structural support to the open well.
 Kachha wells :
 These wells do not provided with lining.
 As such these are temporary wells of very shallow depths.
 Such wells can be constructed in hard soils where the well walls can stand vertically without
any support.
 Further, these wells can be constructed only where water table is very near the ground
surface.
 Though these wells are quite cheap and useful, they may collapse after some time and may
sometimes prove to be dangerous.
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17.  Wells with Impervious lining (Pucca wells) :
 These are the most stable and useful type of wells.
 For constructing such a well first of all a pit is excavated using hand
tools such as pick and shovel up to the moist soil.
 A curb is then lowered into the pit. A curb is a circular ring of R.C.C.,
timber or steel having a cutting edge at the bottom.
 Masonry or concrete lining is then built up on the curb up to a few
meters above the ground surface.
 The soil in the pit is then excavated, and as the excavation proceeds
the curb along with the lining sinks down.
 As the lining sinks down it is further extended at the top.
 In a well lined with an impervious lining on its sides, the flow is not
radial.
 The water enters only from the bottom and the flow becomes spherical
when once the cavity has been formed at the bottom.
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Fig. Shallow Well with Pucca Lining

19.  Well with pervious lining :
 Such type of wells are suitable in
coarse formations.
 The lining consists of dry bricks or
stones with no mortar or binding
material. Due to this, water enters
from sides, and the flow is
therefore, radial.
 Such wells are generally plugged at
the bottom.
 If there is no plug at the bottom,
the flow is a combination of radial
and spherical pattern.
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Fig. Well with Pervious Lining

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