56 Chapter: - 4 IMPACT OF GEOMORPHIC FACTORS ON WATER RESOURCES Physiography, climate, geology and geomorphology play a key role in the evaluation of the potential of water resources. In order to get veracious knowledge about the availability of water resources, it is immense important to study the impact of these factors. The area under study possesses unique physiography, geology and climate. Large part of the study area is encompassed by Deccan basalt, while alluvium formation occupies the central position. Nature of the aquifers is controlled by process of weathering, fracture, faults and lineaments. Surface and sub-surface hydrological features such as geological structures, lineaments, rock types, drainage density, water bodies and thickness of overburden weathered material play an important role in groundwater occurrence in different geological formation or aquifers. Drainage characteristics of the watershed are also the center of attention to hydrologists and geomorphologists. Following geomorphic factors are considered to perceive water resources within the district: 4.1 PHYSIOGRAPHY: Potential of water resources are restrained by physical features. Physiography refers to the arrangement or portrait of the landforms of given area in a broad sense. Dhule district exhibits varied physiographical features ranging from mountain ranges, hills, valleys, flood plain, plateau etc. The area which is under focus can be divided into following physiographic units: 4.1.1 Satpura, Dhanora and Galna Ranges: Dhule district is bounded by Satpura ranges from the north while Danora and Galna hills from south. Aner, Arunavati, Ambad, Kordi rivers have their fountain- head from southern slopes of Satpura ranges and flows southward to join Tapi river. While Dhanora and Galna hills forms the source regions of Panzara, Burai, Amaravati, Kan, Bori etc. Hence these ranges are assumed as donor zone, these areas are poor in groundwater, because of steep slope, thin layer of weathered material, absence of soil cover and degraded vegetation. 4.1.2 Flood Plain: Flood plain occupies southern part of Shirpur tehsil and northern part of Shindkheda tehsil. This formation is composed of the material deposited by Tapi and
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Chapter: - 4
IMPACT OF GEOMORPHIC FACTORS ON WATER
RESOURCES
Physiography, climate, geology and geomorphology play a key role in the
evaluation of the potential of water resources. In order to get veracious knowledge
about the availability of water resources, it is immense important to study the impact
of these factors. The area under study possesses unique physiography, geology and
climate. Large part of the study area is encompassed by Deccan basalt, while alluvium
formation occupies the central position. Nature of the aquifers is controlled by process
of weathering, fracture, faults and lineaments. Surface and sub-surface hydrological
features such as geological structures, lineaments, rock types, drainage density, water
bodies and thickness of overburden weathered material play an important role in
groundwater occurrence in different geological formation or aquifers. Drainage
characteristics of the watershed are also the center of attention to hydrologists and
geomorphologists. Following geomorphic factors are considered to perceive water
resources within the district:
4.1 PHYSIOGRAPHY:
Potential of water resources are restrained by physical features. Physiography
refers to the arrangement or portrait of the landforms of given area in a broad sense.
Dhule district exhibits varied physiographical features ranging from mountain ranges,
hills, valleys, flood plain, plateau etc. The area which is under focus can be divided
into following physiographic units:
4.1.1 Satpura, Dhanora and Galna Ranges:
Dhule district is bounded by Satpura ranges from the north while Danora
and Galna hills from south. Aner, Arunavati, Ambad, Kordi rivers have their fountain-
head from southern slopes of Satpura ranges and flows southward to join Tapi river.
While Dhanora and Galna hills forms the source regions of Panzara, Burai,
Amaravati, Kan, Bori etc. Hence these ranges are assumed as donor zone, these areas
are poor in groundwater, because of steep slope, thin layer of weathered material,
absence of soil cover and degraded vegetation.
4.1.2 Flood Plain:
Flood plain occupies southern part of Shirpur tehsil and northern part of
Shindkheda tehsil. This formation is composed of the material deposited by Tapi and
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her tributaries. It comprises clay, silt, sand, pebbles etc. This zone is nothing but a
thick layer of alluvium. Flood plain receives water from piedmont zone. So Tapi flood
plain possesses a good deal of groundwater resources. In general flood plain is
suitable for percolation of water. But impervious layer of yellow soil and hard pan of
calcareous concretions are prevalent at many places which affect vertical infiltration
(Khanapurkar, 2010).
4.1.3 The Piedmont Zone / Talus and Scree Deposits:
Satpura Mountain consists of talus and scree. Locally it is also known as
Bazada. Thickness of this zones reaches up to 50 m. at many places. This formation
comprises mainly boulders, pebbles, coarse and fine sand as well as clay, which is
poorly sorted and unconsolidated. Hence it is highly porous and normally yields
copious groundwater. At present the dug wells and shallow tube wells are dry up
(Khanapurkar, 2010).
4.1.4 The Deccan Plateau or Upland Region:
Considerable part of the Dhule district that lies to the south of Tapi river is
suffused by Deccan plateau. It is the part of Maharashtra plateau covered by lava
flows. It is rugged and undulating in nature. Deccan basalt is exposed at many places.
This region is traversed by streams and rivers such as Panzara, Burai, Amaravati,
Bori, Kan etc. Numerous dykes are learnt in this region. Upland region holds low to
moderate groundwater depending upon depth of weathering. Residual Hills are
basically the hard rock left behind after erosion has occurred. Subba Rao (2001) has
also opined that residual hills are not suitable for groundwater exploration because of
their poor water storage capacity.
4.2 WEATHERING:
Weathering is decay and disintegration of solid rocks in situ.
According to C. D. Olliver (1969) weathering is the breakdown and alteration of
minerals near the earth’s surface to produce that are more in equilibrium with newly
imposed physico-chemical conditions (Savindra Sing, 1999). The process of
weathering is of three types: (1) Physical or Mechanical Weathering, (2) Chemical
Weathering and (3) Biological Weathering. Whenever hard rock such as Deccan
Basalt matters, weathering processes have immense impact over water resources.
Large scale groundwater storage is provided by weathered rock volume, the network
of joints on accounts of cooling process, fractures and fissures that develop due to
earth movements that occurred from time to time as well those due to denudational
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processes (Jagtap, 1984). The weathered and fractured zones forms groundwater
potential zones (Pradeep Kumar, 2010).
Temperature and rainfall are the key factors that determine the rate of
weathering and depth of weathered material. Temperature is not only involved in
physical disintegration of rocks but it also enhances rate chemical reactions. Rainfall
increases the availability of water which is principal reagent in weathering process
(Borse, 2006).
In order to get detailed information regarding water tables during pre-monsoon
and post-monsoon season as well as depth of weathering, alluvial deposition, depths
of wells, intensive field work was carried out comprising 114 observation wells. From
present research work it is revealed that Deccan basalt is subjected to weathering at
various degrees. The thickness of weathered material varies from 0.5 m. to 12.6 m.
within study area. Weathered profile is almost not found in Tapi valley because of
excessive alluvial deposition. A thin veneer of weathered material is learnt in hilly
area, but as distance from the mountain crest increases the depth of weathering
increases. Hadakhed (10 m.), Songir (9 m.), Dhule (12m.), Chinchwar (10.25 m.),
Deshshirvade (12.6 m.), Shivarimal (10.5 m.) are the prominent examples of deep
weathering. Weathered profile of near about half of observation wells is less than 3 m.
(Photo Nos. 1, 2, 3, 4, 5 and 7)
4.3 SLOPE:
Slope is the degree or amount of inclination of ground surface. Slope is one of
the indicators for groundwater prospects. It controls the infiltration of water into
subsurface. In the gentle slope area, the surface runoff is slow allowing more time for
rainwater to percolate, whereas steep slope facilitates high runoff allowing less
residence time for rainwater and hence comparatively less infiltration (Pradeep Kumar
et al, 2010).
Slope of the basin is morphometric factor affecting the discharge
characteristics of river (Nagrale, 2010). Slopes which are convex tends to spread the
over land and thus favors infiltration where as slope which are concave promotes
concentration of flow and linear runoff (Kirby, 1978). The high potential zones
correspond to the fracture valleys, valley fills, pediments and denudational slope,
which coincide with the low slope and high lineaments density areas. The low zone
mainly comprises structural hills and escarpments and these act as run-off zones
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(Vijith, H., 2007). In other words it is a measure of change in elevation. Topography
determines the speed with which the runoff will reach to the river. Rain that falls over
Fig. No. 4.1
steep mountainous areas will certainly reach the river faster than the flat or gentle
sloping areas.
In the present study, the area under focus is grouped into five classes
according to the degree of slope (Fig. 2.1). The areas having slope less than 50
are
designated as nearly level ground or very gentle slope. About 86.86% surface of the
district is characterized by very gentle slope which favors groundwater infiltration
(Table No. 4.1). While 6.5% area lies in between 50 to 10
0 which is known as
moderate slope. Moderate steep and steep slope are very small in areal extent in the
study area. It is confined to the Satpura ranges in the north and north eastern part and
Dhanora, Galna Hills to the south. The degree of the slope also plays an important
role in the infiltration. As far as groundwater is concerned, flat areas are capable of
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holding surface runoff, which in turn facilitates recharge. Whereas in the elevated
areas, where the slope amount is high, there is be high run-off and low infiltration.
Hence, due to flat or rolling topography there are better chances of groundwater
percolation in the study area.
Table No. 4.1 Area Under Slope in Dhule District.
Sr. No. Slope Category Area
In sq. km. Percent
1 00-5
0 7003.640 86.860
2 50-10
0 527.165 6.538
3 100-15
0 235.190 2.917
4 150-20
0 160.993 1.997
5 > 200 136.122 1.688
Total 8063.110 100.000
Source: Computed by the researcher.
4.4 LINEAMENTS:
A lineament may be a fault, fracture; master joint, a long and linear geological
formation, the straight course of streams, vegetation alignment or topographic
linearity. It is a straight or gently curved, lengthy topographic feature expressed as
depressions or lines of depressions (O’Leary et al., 1976). It is itself an expression of
the underlying structural features. In simple words, lineaments are linear fractures
commonly associated with dislocation and deformation. Lineaments are fractures and
faults that play an important role in groundwater studies particularly in hard rock
regions. They are linear or curvilinear features can play a major role in identifying
suitable sites for groundwater abstraction because they reflect rock structures fractures
and faults through which water can travel up to several kilom.s. They are the area of
zones of increased porosity and permeability in hard rock areas. Many groundwater
potential zones are located along fracture zones hence identification of lineament is
important in groundwater studies. Lineaments provide the pathway for groundwater
movement and are hydrogeologically very important. The lineament intersection areas
are considered as the groundwater potential zones. At last their presence should be
confirmed with ground truth verification (Borse, 2006).
Although lineaments have been identified throughout the area, the lineaments
in the pediplain or valley fill area are considering significant from groundwater
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Fig. No. 4.2
occurrences point of view (Pradeep Kumar, 2010). Lineaments like joints, fractures
etc. are developed generally due to tectonic stress and tension provide important clues
on surface feature and are responsible for infiltration surface runoff in to the surface
and also for development and storage groundwater (Subba Rao el at, 2001).
Remote sensing data provides useful information to identify structural features
and lineaments. Lineaments are the linear features of tectonic origin that are identified
as long, narrow and relatively straight total alignments visible in satellite image.
District Resource Map of Dhule District (GSI, 2001) and the satellite image have been
visually interpreted to identify the lineaments of the study area. The data has been
checked by field visits and study. Identified lineaments are of varying dimension with
different orientation.
The prominent directions of lineaments are NE-SW, E-W and N-S as shown in
lineament map (Fig. 4.3). Lineaments with considerable length are observed in south
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Fig. No. 4.3
and south-eastern part of the study area which extends for 80 to 100 km. They are
parallel to the Dhanora and Galna Hills. Few N-S trending lineaments are marked in
the same region. Some of the lineaments present in north which are varied in
directions. The mapped structural lineaments are analyzed using the lineament
density param.s. The lineament density map of the study area (Fig. 4.4) shows that
lineament density, range from 0.0 to 1.36 km/sq. km. The high lineament density
areas are found in patches all over the district except north eastern and central part of
eastern territory. It indicates the areas of high groundwater potential. Lineament
density of 0.8 to 1.36 km/sq. km. is discovered in east and central Shirpur tehsil,
central part of Sakri tehsil from north to south and central part of Dhule tehsil from
east to west. The region of medium density (0.4 to 0.8 km/sq. km.) can be noticed
around areas of high density. Areas of medium density take up more space in Sakri
and Dhule tehsil along Panzara river. A large part of the Panzara basin is occupied by
low density indicating a poor groundwater potential. Shirpur tehsil has the lowest
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density. Based on the lineament density it is inferred that the groundwater prospects
are poor in a large part of the study area.
4.5 DRAINAGE:
A drainage basin is well defined area of the land surface where water gets
together to a single point to join a river, a lake or a sea. The drainage basin acts as a
funnel by collecting all the water within basin and channeling it to a single point.
Each drainage basin is separated topographically from adjacent basins by an elevated
part such as a ridge, hill or mountain known as water divide. In hydrology, the
drainage basin is a logical unit of focus for studying the movement of water within the
hydrological cycle, because the majority of water that discharge from the basin outlet
originated as precipitation falling on the basin.
• Shape will contribute to the speed with which the runoff reaches a river. A
long thin catchment will take longer to drain than a circular catchment.
Circular basin causes higher discharge during short period as compared to a
long period for elongated basin (Nagrale, 2010).
• Size will help to determine the amount of water reaching the river, as the
larger the catchment greater the potential for flooding. If the area of the basin
is large, the total flood will take more time to pass the outlet. Thereby the base
of the hydrograph of the flood flow will widen out and consequently reducing
the peak flow.
• Topography determines the speed of water with which the runoff will reach a
river. Clearly rain that falls in steep mountain areas will reach the river faster
than flat or gently sloping areas.
• Drainage pattern of any terrain reflects the characteristics of the surface as
well as sub-surface formations. More the drainage density, higher would be
runoff. Thus the drainage density characterized the runoff in the area. In other
words, it indicates the quantum of rain water that could have infiltrate, hence
lesser the drainage density, higher the probability of recharge of potential
groundwater zone. Drainage density also has a bearing on the permeability of
the rocks.
• Total amount of water available within Catchment area with know or
estimated precipitation depends on its size.
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The groundwater prospect of isolated hills is poor. (Pradeep Kumar, 2010).
Bifurcation ratio characteristically ranges between 3 to 5 for watershed because the
influence of geological structure on the drainage network is negligible. The
bifurcation ratio between 1st and 2
nd order streams may be considerably higher than
bifurcation ratio (Rb) of higher order streams. This is indicative for a state of
accelerated erosion. High bifurcation ratio is common where the effects of geological
structure are dominant but shape of the basin also has an important effect for low
drainage and large basin with comparatively low order. Main streams are common in
resistant rocks whereas high drainage densities and higher order basins are common in
soft rocks (Nagrale, 2007).
The shape of the drainage basin is also governed by the rate at which water
enters the stream. The shape of the drainage basin is generally expressed by from
factor and compactness coefficient (Santosh Kumar Sing, 1977).
4.6 ROCK PROPERTIES:
Precipitation is the primary source of groundwater. Precipitated water must
percolate down through the vadose zone or soil to reach the zone of saturation. The
rate of infiltration is a function of soil type, rock type, antecedent water and time.
Movement of groundwater depends on rock and sediment properties and the
groundwater’s flow potential. Porosity, permeability, specific yield and specific
retention are important properties of groundwater flow.
4.6.1 Aquifer:
In Latin language ‘Aqua’ means ‘water’ and ‘ferre’ means ‘produce’ or ‘bear’.
Thus Aquifer is composed of these two words. An aquifer may be defined as a
formation that contains sufficient saturated material to yield significant quantity of
water to wells and springs (Todd, 1980). These are unconsolidated rocks composed of
sand and gravel with an ability to store and transmit water. Aquifers should be
permeable and porous in nature. An impermeable layer of rock is present beneath the
permeable strata so as to store water. An aquifer may extend over an extensive area in
horizontal as well as vertical direction.
Two types of aquifers have been noticed in Dhule district, namely Basaltic and
Alluvial aquifers. About 85% part of the district is suffused by Deccan Basalt. Deccan
traps of India are comparatively older in age, and less permeable. This is due to the
fact that the primary porosity in Deccan traps is much less and also because the
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vesicles are filled with secondary minerals. Secondary porosity is developed due to
jointing and weathering (Singhal, 1997). In highly weathered rock as well as contact
between two flows embedded with gravel or exfoliated pebbles, boulder and gravel is
the most favorable area for huge storage of groundwater (Sarbhukan, 2001).
Groundwater occurs in semi-confined and confined conditions in most of the Deccan
trap areas.
Alluvial is another aquifer of the study area. It is formed due to the
accumulation of sediments in Tapi rift valley by Tapi her tributaries. It is composed of
unconsolidated material like pebbles, gravel, sand and silt hence highly porous.
Alluvial aquifer possesses ample quantity of water. Groundwater in Tapi and Purna
alluvial area occurs under water table and unconfined conditions. Alluvium acts as
natural store of water (Joshi, 1979).
4.6.2 Porosity:
Diversity in the material results in the spaces during the rock formation. These
spaces are called as pore spaces, voids or interstices. They are filled with
groundwater. Groundwater dwells in these pore spaces. The porosity of soil or a
geologic material is the ratio of the volume of pore space in a unit of material to the
total volume of material. Porosity is often expressed as a percentage. The shape and
arrangement of soil particles help to determine porosity. Infiltration, groundwater
movement and storage occur in these void spaces. Therefore pore spaces are
noteworthy in the study of groundwater. The interstices come into existence during
geological processes. Particles exist in many shapes and these shapes pack in a variety
of ways that may increase or decrease porosity. Generally, a mixture of grain sizes
and shapes, results in lower porosity.
Primary porosity is the space that remains between solid grains or crystals
immediately after sediments accumulation or rock formation. The primary porosity of
the Deccan traps is due to cooling cracks, joints, fissures and open flow junctions,
fractures and occasionally due to porous lava flows. Deccan traps of India are
comparatively older in age, and less permeable. This is due to the fact that the primary
porosity in Deccan traps is much less and also because the vesicles are filled with
secondary minerals (Singhal, 1997).
Because of dissolution or stress the interstices that appear in a rock formation,
after it has formed, is known as Secondary porosity. The secondary porosity is
developed due to jointing and weathering. The various flow units have also been
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Table No. 4.2 Hydrological Properties of Rocks and Sediments
Sr. No. Material Porosity Permeability
(m3/day)
Hydraulic
Conductivity (m3/day)
1 Soils 0.3-0.5 ---- ----
2 Weathered
Rock 0.01-0.5 ---- ----
3 Clay 0.45-0.55 <0.01 0.0002
4 Silt 0.4-0.50 0.0001-1.0 0.08
5 Fine Sand 0.30-0.52 0.01-10.0 2.5
6 Medium Sand 0.30-0.40 10-3000 12
7 Coarse Sand 0.30-0.40 10-3000 45
8 Sandy Gravel 0.20-0.30 0.3-10.0 150
9 Gravel 0.25-0.40 1000-10000 450
10 Conglomerate 0.50-0.25 0.3-3.0 0.2
11 Tuff 0.10-0.80 0.0003-3.0 0.2
12 Lavas (Basalt) 0.01-0.30 0.0003-3.0 0.01
13 Weathered
Rocks 0.01-0.10 >0.0003 0.1-1.4
Source: Dunne and Leopold, 1978.
weathered to varying extent giving rise to murum, a lateritic type of soil which
represents a potential aquifer horizon tapped by dug wells (Singhal, 1997). Near the
ground surface, the porosity is further accentuated by weathered rock, river or stream
alluvium or the lateritic cap over hard basalt; usually contain the phreatic water body.
In the fissures, fractures and flow junctions within the underlying hard basalt,
groundwater occurs under semi-confined state. Circulation of water is most confined
to about 100 m depth below ground surface (Limaye, 1994). Porosity of deep black
soil is 0.60 %. Porosity and Permeability of different formations are given in the
Table No. 4.2.
4.6.3 Permeability:
Permeability is a measure of a soil's or rock's ability to transmit a fluid, usually
water. It is an expression of the connectedness of the pores. The size of pore space
and interconnectivity of the spaces help to determine permeability, so shape and
arrangement of grains play a key role. Water can permeate between granular void or
pore space and fractures between rocks. Larger the pore space, more permeable the
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material. However the more poorly sorted a sample or mixed grain sizes lower the
permeability because the smaller grains fill the openings created by the larger grains.
Water and air move more rapidly in strongly aggregated soils. On the other hand, clay
and silt has low permeability due to small grain sizes with large surface areas, which
results in increased friction. These pore spaces are also not well connected. Deep
black soil consists of high clay and silt, therefore they are poorly permeable.
Infiltration rates are low with massive loss of soil via erosion (Krishna, 2010).
Permeability of this soil is 10-10
cm/sec. Constant infiltration rate of deep black soil is
1.2 cm/hr. and 1.6 cm/hr. in compact and ploughed conditions. Fractures in the hard
rock also help to determine permeability.
4.7 HYDROGEOMORPHOLOGY:
Hydrogeomorphology has been defined as an interdisciplinary science that
focuses on the interaction and linkage of hydrologic processes with landforms or earth
materials and the interaction of geomorphic processes with surface and subsurface
water in temporal and spatial dimensions (Sidle and Onda, 2004). The concept of
Hydrogeomorphology is useful to describe the link between water and geomorphic
conditions. Hydrogeomorphological mapping is an integrated, applied geo-scientific
approach for groundwater prospecting zonation. The location of groundwater
potential and infiltration areas becomes perceptible by using this type of
hydrogeomorphological zoning.
The hydrogeomorphological map of Dhule district (Fig. No. 4.5) represents
the result of combination of geological, hydrogeological and geomorphological
factors. In the present study hydrogeomorphological map has been prepared using
visual interpretation of satellite image and hydrogeomorphological map provided by
GSDA, Dhule. The area under the study is classified in different
hydrogeomorphological zones such as alluvial plain, valley fills, eroded land, un-
dissected plateau, medium dissected plateau, highly dissected plateau and Western
Ghat section.
4.7.1 Alluvial Plain: Alluvial plain and flood plain constitute the main landforms of
fluvial origin. Gently sloping plains on the banks of Tapi river and lower reaches of
Panzara, Burai and Arunavati rivers are clearly marked in the study area. The contour
of 150 m. clearly demarcates the alluvium plan both to the sides of Tapi river.
Alluvial deposition occurs along both banks of Tapi river and its tributaries in Shirpur
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and Shindkheda tehsils. This formation accounts 384.47 sq. km. area means 4.77%
territory of the district. The alluvium comprises clay, silt, sand, gravel, pebbles and
occasionally boulders. The study reveals that paleo-channels and alluvial plain are the
geomorphological features with excellent potential for groundwater occurrence. The
groundwater can be tapped through shallow and deep tube wells in alluvial plains and
flood plains. The wells tapping the flood plains generally give high yield with good
quality of water.
Fig. No. 4.4
4.7.2 Valley Fill: It is described as the deposition of unconsolidated materials in the
narrow fluvial valley. These are the features formed by depositional processes. They
are composed of loose sediments such as pebbles, gravel, sand and silt. Valley fills
are located along the Panzara river in Sakri and Dhule tehsil and along Burai river in
Sakri and Shindkheda tehsil. Valley fill captures very limited area in Shirpur tehsil.
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Due to coarser materials it has high permeability. They have covered an area of 506.8
sq. km. which is about 6.28 % of the district. The groundwater prospect of this area is
expected to be good depending upon the thickness of the fill material (Pradeep
Kumar, 2010).
Table No. 4.3 Hydrogeomorphic Units of Dhule District.
Sr. No. Hydrogeomorphic Unit Area in Sq. Km. Area in Percent
1 Valley Fill 506.80 6.28
2 Alluvial Plain 384.47 4.77
3 Eroded Land 692.41 8.58
4 Highly Dissected Plateau 535.04 6.65
5 Medium Dissected Plateau 3061.01 37.96
6 Un-Dissected Plateau 2609.70 32.37
7 Western Ghat Section 273.59 3.29
Total 8063.11 100.00
Source: Computed by Researcher.
4.7.3 Eroded Land: The eroded land is the outcome of erosional processes. The
small streams have cut the land and it is converted in to eroded land. Such features are
located mainly along Tapi river in Shirpur and Shindkheda tehsil, while strips of land
are eroded along Panzara and Aner rivers in Shindkheda and Shirpur tehsils
respectively. About 692.41 sq. km. area is eroded which comprises 8.59% of the total
area of the district.
4.7.4 Un-dissected Plateau: Most of the Southern part of the district along Panzara
and Bori rivers is covered by un-dissected plateau. It also extends up to lower reaches
of Panzara and Burai rivers. It occurs almost in all tehsils of the study area. South and
south-western part of Shirpur tehsil has also un-dissected plateau. It exactly coincides
with the High Water Potential Zone (Fig No. 4.5). Un-dissected plateau has good
weathered profile and hence high potential of groundwater is found. Undissected
plateau is spread over 2609.7 sq. km. It is 32.37 % of the study area.
4.7.5 Medium Dissected Plateau: Major part of the study area is subjected to erosion
process and weathering, so it is called medium dissected plateau. Most of the north-
eastern and eastern part of Sakri tehsil is occupied by medium dissected plateau. Near
about half of Shindkheda tehsil is formed of medium dissected plateau. This feature is
also spread over more than half of Shirpur tehsil. It occupies 3061.1 sq. km. area of
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Dhule district which is 37.97% of the study area. Medium Dissected Plateau nearly
corresponds with area of Moderate Water Potential Zone (fig No. 4.5). Here,
prospectus of groundwater occurrence is moderate.
4.7.6 Highly dissected plateau: It is located in the most southern part of Sakri tehsil.
A very small patch of highly dissected plateau is observed in middle-east part of
Shirpur tehsil. It covers an area of 535.4 sq. km. and comprises 6.65% of the study
area. It has low potential of groundwater.
4.7.7 Western Ghat Section: A small area of Sakri tehsil in the west is covered by
Western Ghat section. It occupies 273.59 sq. km. and 3.39% of the total area of the
district. It is also poor with respect of groundwater potential.
4.8 MORPHOLOGICAL CLASSIFICATION:
Morphology plays a significant role in influencing the hydrological conditions
and behavior of groundwater reservoirs. According to this classification, watersheds
have been classified in to three categories on the basis of their locations in river basin
and physiographic consideration of the terrain (Maggirwar, 1990). They are as
follows:
4.8.1 Runoff Zone:
Runoff is situated in the upland area near water divide, with highly dissected
morphological conditions, steep slopes, and undulating topography. It is characterized
by barren hills, rocky outcrops, poorly weathered mantle and absence of vegetation.
Hence it leads to poor infiltration and rapid runoff of rainfall. Hydrological conditions
of this area indicate poor or absence of aquifer. Groundwater in the runoff zone
occurs in limited and perched water table conditions (Maggirwar, 1990). In present
research study area Satpura hills, Dhanora-Galna Hills and Western Ghat section act
as runoff zone. It accounts about1397.91 sq. km. area which is 17.34% of the study
area. Dykes can be also including in this zone. (Table No. 4.4).
4.8.2 Recharge Zone:
Recharge zone is located in the middle course of the basin. Morphologically
the area is moderately dissected and drained by streams of higher order. It possesses
moderate relief, shallow soil cover. These conditions are favorable for moderate
infiltration and recharge of groundwater. Hence the area has groundwater and is
suitable for groundwater development. This is zone of active weathering. Recharge
zone comprises the landforms like piedmont plain, moderately dissected un-dissected
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plateau. Well yield of recharge zone is seasonal and it can support only kharip and
rabbi crops. Recharge zone occupies 3665.62 sq. km. area which is 45.46% of the
study area. It is distributed all over the study area except alluvial plain of Tapi river.
Fig. No. 4.5
4.8.3 Storage Zone:
Low lying areas and lower reaches of the river basins fall in this category. It is
characterized by poor drainage conditions. The obese soil cover of storage zone is
either derived by deep weathering or by alluvial deposition. Due to high thickness of
weathered profile and porosity, it holds substantial quantity of water. This zone is
benefited by good recharge conditions and getting recharge by groundwater inflow
from upland areas after rainy season. In this zone groundwater occurs under water
table conditions. Hydrologically, storage zone is highly suitable for groundwater
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exploration. Storage zone is discovered in the alluvial plain and eroded land of the
Tapi valley. It also covers valley fills of her tributaries and streams. Storage is zone is
admeasured 2999.58 sq. km. in the study area. Dug and tube wells are characterized
Table No. 4.4 Area Under Morphological Zones in Dhule District.
Source: Computed by researcher.
by high yield 100 to 150 cu. m./day. Hence they support the crops all round the year.
Storage zones are highly fertile and productive for good yield.
4.9 MAJOR GROUNDWATER PROVINCES OF DHULE DISTRICT:
Groundwater Province is an area characterized by a general similarity in the
mode of occurrence of groundwater (Sarbhukan, 2001). Two groundwater provinces
are noticed in the study area. They are as follows:
4.9.1 Deccan Trap Groundwater Province:
The Deccan Trap comprises several flows of Basalt which are supposed to
have extruded from fissure eruptions. It occupies 85 % of total area of Dhule district,
which is a major groundwater province. The flows have been intruded by large
number of dykes of doleritic composition. The dykes are trends in an ENE-WSW
direction and a few are N-S or WNE-ESE trends. Basalt flows are of the “pahoehoe”
and the “aa” types. The groundwater learnt in the surface layers down to the depth of
20 m. under unconfined conditions in the weathered zone, vesicular or amygdaloidal
basalt, jointed and fractured massive basalt. The water bearing strata occurring below
30 m. depth, beneath the redbole and dense massive basalt, exhibit semi-confined to
confined conditions. On the elevated plateau tops having good areal extent, local
water table develops in top most layers and the well in such areas show rapid decline
of water levels in post-monsoon season and becomes dry during summer. At the foot
hill zone the water table is relatively shallow near the water courses and deep away
from it and near the water divides. In the valleys and plains of river basin, the water
Sr. No. Zone Category Area
in sq. Km. in Percent
1 Storage Zone 2999.58 37.20
2 Recharge Zone 3665.62 45.46
3 Runoff Zone 1397.91 17.34
Total 8063.11 100.00
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table aquifer occurs at the shallow depth and the wells in such areas do not go dry and
sustain perennial yield except in extreme summer or drought conditions.
The depth, water table and yield of wells hinges on the permeability of the
lava flows. The average depth of wells in the study area ranges from 6 to 21.5 m. and
depth of water table ranges between 1.25 to 13.5 m. The yield of the dug wells varies
from 60 to 125 cu.m/day, whereas that of bore wells varies from 2 to > 20 cu.m /hr,
however in most of the bore wells it ranges between 2 to 10 cu. m./hr. Thus
geological and geomorphological formation of the Trap territory is accountable for
the low availability of groundwater. Structure, jointing pattern and depth of
weathering determines water holding capacity and the movement of groundwater
within different lave flows.
4.9.2 Alluvial Groundwater Province:
Alluvial deposits of Tapi river valley occur in long narrow basin, which are
probably caused by faulting. About 15% of the district is occupied by the alluvium. It
consists of clay, silt, sand, gravels and boulders etc. The beds of sand and gravels are
discontinuous and lenticular and pinch out laterally within short distance. They are
mixed with large proportions of clayey material rendering delimiting of individuals
granular horizons. As per groundwater exploration data alluvium is encountered down
to 100 m. depth. Groundwater occurs under water table, semi-confined and confined
conditions in inter granular pore spaces of gravel and sand. The average depths of
tube wells in this part of study area are ranges from 30 to 90 m. and depth of water
table ranges between 12.5 to 56.5 m. The yield of the dug wells varies between150
and 200 cum /day, whereas that of exploratory wells varies from 1.50 to 6.00 lit./sec.
as per exploration data. The yielding of the tube wells drilled by GSDA ranges from
20 to 250 cum / hr.
4.10 HYDROGEOMORPHIC SECTIONS:
Delineation of groundwater resources is of paramount importance. In the view
of present day’s vast and ever increasing demand of water in various sectors, it is
crucial to know the potentials of groundwater to planners, administrator and
researchers. Since the assessment of groundwater resources is related to mainly
indirect evidences, it is difficult task.
In order to study groundwater resources of Dhule district a simple and
conventional approach is adopted. Study of occurrence of groundwater is multivariate
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in nature. The wells are the important tools or means which gives us an important
information regarding occurrence of water, nature of aquifers, properties of material,
water table levels and water quality aspects. Therefore major thrust has been given on
well inventory data (Borse, 2006). A questionnaire was formulated including major
Fig. No. 4.6
aspects of dug and tube wells to collect data regarding the occurrence of groundwater.
Whole district is divided into six cross sections. These cross sections are framed from
Satpura ranges in the north to Dhanora and Galna hills in the south across
physiographic divisions and major rivers. Total114 dug and tube wells are selected as
a sample for present study. This was supplemented by the oral information from the
farmers. The observation wells are selected along motorable road at an interval of
near about 5 km. It is because the preference was given to cover major geomorphic
units and geological formations. These north south running cross sections of the study
area gives an idea about subsurface geological formation, depth of weathering,
occurrence of red and green bole. They also help us to understand the depth, width of
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alluvial deposition in Tapi rift valley at various places. Hydrogeomorphic sections of
