CHAPTER 3: DATABASE AND PHYSIOGRAPHY
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Digital Elevation Model (DEM) of Study Area
"The greatest threat to our planet is the belief that someone else will save it"
-Robert Swan CHAPTER 3: DATABASE AND PHYSIOGRAPHY
Data collection and initial data processing plays a crucial role in the GIS and RS modeling. Spatial watershed modeling imposes precise spatial and temporal data. Data collection and projecting data into GIS environment was a difficult task and demands lots of effort and time. The spatial and temporal data were collected from different sources. The collected datasets were correlated, studied sequentially and arranged as per the studies requirements.
3.1 PHYSIOGRAPHY OF THE STUDY OF AREA
The Khadakwasla complex is situated near Pune city, at altitude ranging from of 530 - 566m.The geographical location of the research area is as shown in Figure 3-1. The total area occupied by the basin under study is 530 Km^. The place is situated in the scenic areas in the Sahyadris (Western Ghats) and is around 30 Km from Pune city and 150 km southeast of Mumbai. The study area is situated along with the western margin of the Deccan Plateau, and on leeward side of the Western Ghat crown. The study area is surrounded by hilly regions on its west as well as in south side. The geographical location of research area is Latitude- 18''28'00"N Longitude - 73^ 46' 00" E Khadakwasla Complex is one of the major irrigation projects in Krishna Khore Vikas Mahamandal The major rivers in the area are Mula and Mutha. Both the rivers confluence together in Pune city and then releases their water to the river Bhima. The Khadakwasla Complex which consists of four dams Panshet, Varasgaon, Temghar and Khadakwasla linked together. The complex was formed by keeping in the view of increasing demand of ever expanding Pune city drinking demand as well as irrigation demand of command area. The water from Khadakwasla is mainly supply water to Pune and Cantonment area for drinking and irrigation demands of Haveli, Daund. Indapur and Baramati tehasil.
66 Figure 3-1 Location of study area
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Figure 3-2 Digital Elevation Model (DEM) of study area
3.2 KHADAKWASLA COMPLEX STRUCTURE
Khadakwasla complex is small catchment in Krishna basin. The Krishna basin is largest basin extending over Maharashtra. Kamataka and Andhra Pradesh covering an area of about 2,58.948 km'. Together along with the Tributaries Rivers in the Krishna basin drains about 708 km of western ghat. The details of four dams which together forms the Khadakwasla complex discussed in details
3.2.1 Panshet dam
Panshet dam is also known as Tanajisagar dam. The dam is located on River Ambi and is about 50 Km from Pune city. The dam was mainly constructed for irrigation in late 1950s. The dam has height of 63.56 meter and length of about 1.039 meter. The gross storage capacity of the dam is 303 Mm^ The Panshet dam is masonry gravity dam. Panshet dam is on the higher elevation as compared to other dams in the complex. It is about 30 meter higher than Khadakwasla dam. Earlier there was a small lake below the Panshet dam constructed at Khadakwasla village when Captain Fife RE of British Army in 1863 identified the necessity of high level reservoir.
68 Subsequent detailed investigations and surveys: the man-made lake was built and named Khadakwasla Lake or Lake Fife. The construction of the lake commenced in 1869 and completed in 1879. On .luly 12"' 1961 there were devastating flood occurred in the Pune city. The lake was already 90% full due to continuous rainfall from June 18"'- July 12"' 1961 and water from Panshet and Varasgaon was continuously flowing to the lake. The new lake embankment could not able to bear the water pressure from the catchment runoff water and finally breaks on the 12"' July causing flood in Pune city. The failure of lake is attributed to inadequate provisions for the water release during emergency.
3.2.2 Varasgaon dam
Varasgaon dam is also known as Vir Baji Pasalkar dam. The dam is constructed on River Mose. The dam was constructed mainly for supply of water to the Khadakwasla reservoir for further use. The dam has height of 66.6 meter and length of about 780 meter. The gross storage capacity of the dam is 375 Mm . The dam is earthen masonry gravity type of dam.
3.2.3 Temghar dam
The Temghar dam is located near village Temghar on River Mutha. The dam is located about 50 Km from Pune city. Mutha River is right bank tributary of River Bhima and flows through Mulshi and Haveli Tehsil and meets River Mula. The dam construction was completed in year 2000.The dam has height of 42.5 meter and length of about 1,075 meter. The gross storage capacity of the dam is 107.96 Mm^ The dam is earthen gravity type of dam.
3.2.4 Khadakwasla dam
Khadakwasla dam construction was completed in 2005. The major concern in the dam construction was to supply water for drinking and irrigation to command area. The dam is connected to Panshet and Varasgaon dam in the upstream where the Mose and Ambi river meets each other. The river Mutha and Temghar water flow also meets the same confluence of Panshet, Varasgaon and then the entire water released into
69 Khadakwasla. The dam has height of 32 meter and length of about 1.500 meter. The gross storage capacity of the dam is 86 Mm . The dam is earthen gravity type of dam. The catchments of all the four dams mentioned above are the scenic areas in the Sahyadri's and western ghat. The contour map and Triangulated Irregular Network (TIN) was generated from contours, shows elevation information is shown in Figure 3-3 and Figure 3-4. TIN was used to study the surface topography of the study area.
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Figure 3-3 Contour map of study area
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Triangulated Irregular Network (TIN) for Study Area
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Figure 3-4 Triangulated irregular network (TIN)
70 3.3 TECHNICAL DETAILS OF DAMS IN STUDY AREA
The technical details of dams in the study area were as presented in Table 3.1. Khadakwasla Panshet Varasgaon Temghar Sr.No. Description Dam Dam Dam Dam 1 Source of River Mutha Ambi Mose Mutha 2 State Maharashtra Maharashtra Maharashtra Maharashtra 3 District Pune Pune Pune Pune 4 Taluka Haveli Velha Velha Mulshi 5 Latitude 18" 28" 00"N 18" 22" N 18" 23" N 18" 27" N 6 Longitude 73" 46" 00"E 73" 35' E 73" 37' E 73" 32* E Catchment area 7 501.80 120.3 130 37.70 (Km') Composite Earthen 8 Type of Dam (Masonry and Earthen Earthen /Gravity / Earthen Dam) Masonry Masonry Ogee shaped with Ogee type 9 Spillway Ogee type UNGATED radial gates Saddle Spillway Gross Capacity 10 86 303 375 107.96 (Mcum) Dead Storage 11 30 9 12 2.95 (Mcum) Live Storage 12 56 294 363 105 (Mcum) Length of Dam 13 1500 765 780 1075 (M) Length of 14 168 56 72 72 Spillway (M) No of Gates and 4 No. 12.19' 15 11 No.40'X 15" 5 No. 12'X 5' - Sizes X4.87" Design Flood 16 Discharge 2775 1162.40 1470.08 736 (Cum/Sec) Maximum height 17 of Dam in the 31.79 58.83 62.85 86.80 River Bed (M) Maximum water 18 82.72/28.93 636.72/56.37 640.41/42.08 710.12 level (M)
71 Area Under 19 Submergence 1480 1760 2420 499.034 (Hect.) Top of Dam Level 20 586.21 639.13 642.85 711.40 (M) Full Reservoir 21 582.47 636.72 639.50 706.50 Level (m) Mean Draw Down 22 576.38 609.60 610.25 661.40 Level (M) River Bed Level 23 554.45 580.35 580.42 641.56 (M) Spillway Crest 24 578.20 631.55 634.63 706.5 Level (M) L.L.LO. 25 - 594.20 591.00 - Sill (M) 26 Discharge (Cus) - 314-814 250-520 - H. L. LO. 27 - 612.65 616.80 - Sill (M) 28 Discharge (Cus) - 784-2160 120-1412 285 Power outlet 29 - 612.04 612.20 - Level (M) Canal Bed Level 30 574.24 - - - (M) Gross Command 31 97100 - - 2000 Area (Hect.) Culturable 32 Command Area 88460 - - 1600 (Hect.) Average Rainfall 33 740 2100 2100 2100 (mm) Irrigable area 34 62146 - - 1000 (Hect.) Length of Canal 35 202 - - - (Km) Year of Project 36 1961 1962 1976 2000 Starting Year of Project 37 2005 1968 1994 2010 Completion
Table 3-1 Technical Details of dams In study area
72 The Figure 3-5 and Figure 3-6 shows the dams and rivers respectively as mentioned above Table 3-1.
Figure 3-5 Dams in study area
Figure 3-6 Rivers in study area
73 3.4 CLIMATE
Study area situated on the leeward site of the western ghat hence the climate of Pune is always moderate. The climate of the study area is tropical monsoon type. The climate shows the three distinct seasons summer winter and monsoon. All the seasons mainly persist for more or less four months duration.
3.4.1 Temperature
In the study area the summer remains for three months from March to May. During summer months temperature varies largely. Annual temperature of the study area recorded was 24.6°C while, mean summer temperature was 27.4°C. There is a significant variation in temperature conditions in western Maharashtra throughout the year. Highest temperature recorded in the month of May which exceeds 38°C whereas in winter lowest temperature was recorded less than 15°C. The mean daily maximum temperature for the hottest month was around 40''C and minimum temperature was around 23"C. For the coldest month the temperature varies from 30"C to 12''C. The relative humidity of the area varies from 36% in March to 81% in July and August. During the study temperature data for the year of 1995-2007 was used as graphically represented in Figure 3-7.
Temprature Graph for Khadakwasia Complex Area
•MAX TEMP -MINTEMP
1-1-95 1-1-96 1-1-97 1-1-98 1-1-99 1-1-00 1-1-01 1-1-02 1-1-03 1-1-04 1-1-05 1-1-06 1-1-07
Figure 3-7 Temperature variation from 1995-2007 (Source: IMD, Pune)
74 3.4.2 Rainfall
Being benefitted of location in western ghat the study area receives the good three months of monsoon. Monsoon starts in the area during June& receives up to the September end. Rest of the months are usually without spells and the months April and May sometimes gives torrential rainfall due to local climatic conditions. Average annual rainfall recorded was 2700 mm. The rainfall varies widely within the area and as per the trend increases towards west side. During the study rainfall data for the year of 1995-2007 was used as graphically represented in Figure 3-8.
Rainfall
120
100
-Rainfall
Date
Figure 3-8 Rainfall distribution from 1995-2007 (Source: IMD, Pune) 3.5 LANDUSE
The study area has a rough terrain with majorly having the hilly areas. In the upper eastern part of the area have the valleys which are one of the unique features of the western ghat are seen. The valley areas are associated with the large terrace areas on the sides and tops of the valley. The rock topography of the area exhibits the more variations in the slope of the area from 00.0-30.0 degrees. General slope of the watershed is from east to west side. As there are dams which are constructed on the slopes of the river the water from the Panshet. Varasgaon and Temghar dams comes to the Khadakwasla reservoir through gravity. There is a much difference in the altitude of the area minimum is 648 meters ASL at the edge of the Khadakwasla dam
75 and maximum is above 1100 meters ASL. In the north and south part of watershed large undulations and hilly areas are present. The landuse of the study area has six major classes. The larger area of watershed is having scrub land which is about 46 % of total landuse of watershed. The remaining landuse of watershed comprises of barren land, residential areas, vegetation, agriculture and water with the total percentage in landuse is 22. 7. 9. 12. and 4 respectively. This type of landuse having the more scrub land creates more concerns of siltation in the dam which were also studied in the research course. The details of these were given in the following Table 3.2.
Sr. No Land Type Area (m^) % of total landuse
1 Barren Land 118152382 22
2 Vegetation 45755524 9
3 Scrub Land 245244851 46
4 Residential 36824243 7
5 Agriculture 63987564 12
6 Water 21939085 4
Total 100
Table 3-2 Landuse distribution in study area
3,6 DRAINAGE PATTERN
The study area is having very well drained network of perennial streams. Most of the streams in the study area are perennial in nature and filled with water only during the monsoon season i.e. only during the months of June to September. The streams in the study are originate in the north east and southern part of the study area and flows towards the north-west direction towards the Khadakwasla reservoir. The smaller stream in the study area collects the excess rain water from the hills and plain area and drains it into the rivers. The drainage pattern in the study area shows dendritic type. Dendritic pattern is the most common drainage pattern found. This pattern has hrancheg of the streams like a
76 growth of tree root. This type of patterns developed due to the homogeneous nature of underlying land which has no control over the direction of the tributaries flow path.
Landuse Classirication or study Area +
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Figure 3-9 Landuse map of study area
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ir24-o-H ti > V-^ -^ irji'vu- ^.y^^\y iflS-O-H- L«g«nd «—— Dr»«n«gBLra : ;;'^ 1:3; t:x :!« -1 Me iy 12-0-N 73'ji'o-c irnirt 7y2ro-[ ryzoo-i jyiiri 73'jfO"i 73'J90-| rytrri 7j'4se-t jy4rsn ivuri Figure 3-10 Drainage pattern of study area 77 3.7 SOILS There are three types of soil series, one (Type I - Annapur Soil) corresponding to region away from the river and the other (Type II - Dholwad Soil) for areas near the river and Type III- Sand which found on barren/scrub land and some degraded areas. The distribution of soils in study area is represented in Figure 3-11. Type I: These soils are formed in alluvium and colluviums very gently sloping piedmont pain at an elevation of 650 m above MSL. A horizon soils are fine loamy & have brown to dark yellowish brown, moderately alkaline, clay loam. B horizon is dark brown, moderately alkaline, gravelly clay loam to gravelly sandy clay loam. C horizon is yellowish brown, moderately alkaline, gravelly loamy sand to sandy loam. The thickness of soil ranges from 55 to 85 cm. The texture of A & B horizons is clay loam and sandy clay to gravelly sandy clay loam. Soil cracks develop on drying due to the presence of clay of high shrink - swell nature. They are well drained and have medium water retention capacity. Type II: These soils are formed in basaltic alluvium and occur on gently sloping old levees or inner terraces of the Godavani flood plain at an elevation of about 500 m above MSL. The thickness of soil ranges from 50 to 80 cm. The content of coarse fragments ranges from 20 to 50% between the depths of 15 to 100 cm, while the content of CaCOs ranges from 6 to 21% throughout the depth. Soil texture ranges from clay loam to clay and at places silty clay loam is also met. Its structure ranges from weak fine sub angular blocky to moderate medium sub angular blocky. The texture of B horizon is usually gravelly silty clay to gravelly clay. Type III: This soil type has the biggest particles; and the bigger size of the particles in a soil the better is aeration and drainage of the soil. This soil is granular and consists of rock and mineral particles that are very small. Therefore the texture is gritty. Sandy soil is formed by the rock disintegration and weathering. Sandy soil is considered as good for cultivation of few agricultural crops as it is rich in organic material, but it drains more and results in dehydration of the plants during summer. Sandy soil retains a certain amount of moisture and nutrients. In a way sandy soil is good for plants since it lets the water drain easily, so that it prevents root rot problems. 78 Scjil Type Map -^ Lagcnd SolTyp* 3iMlt»: 4i?; 5»3 1*3: ESI" Figure 3-11 Soil map of study area 3.8 SPATIALDATA USED DURING RESEARCH The GIS mainly uses the Spatial and the temporal data combined together for the processing. The satellite data and the secondary data collected through various sources were authenticated by using a regular field visits to the study area. 3.8.1 Satellite Imagery Satellite image of IRS LISS III. March 2009. and September 2010 were used for research purpose the same is given in the Figure 3-12. Spatial resolution of the image is 30 m. The satellite Linear Imaging Self Scanning Sensor (LISS-III) is a multi- spectral with having a camera operating system in four spectral bands, where three bands in them are operating in visible and near infrared and one and is operating in the SWIR region. 79 jyjivt 7n4-irt /I'jnrt n'^im nirirt /J-JSO-E /r3r