Objectives
• To find a suitable site for dam construction.
• To study Q-GIS and ENVI softwares.
• To find a perfect area for catchment fulfilling requirements of soil, rainfall, slope, etc
• To generate land use/cover classification using LANDSAT 8 satellite images.
• To prepare thematic maps of study area.
Definition
• DAM- A dam is a barrier that impounds water or underground
streams. Reservoirs created by dams not only suppress floods
but also provide water for such activities as irrigation, human
consumption, industrial use, aquaculture, and navigability.
Hydropower is often used in conjunction with dams to
generate electricity.
• CATCHMENT- The collection of rain water over a natural
drainage area during rainfall.
• RESERVOIR- A reservoir usually means an enlarged natural or
artificial lake, storage pond or impoundment created using a
dam or lock to store water.
Reason for dam/catchment construction
• Flood control.
• Agricultural purposes.
• Hydro-electricity.
• Water reservation.
Recently lakhs were affected by severe droughts in Maharashtra.
Due to failure of good monsoon and excessive heat drying up the
rivers resulted in crop failure and subsequently leading to farmer
suicides.
Maharashtra may require more catchment areas which can supply
water in extreme weather or can give relief to affected areas
rather than depending on fresh rains.
Dam site requirement criteria
• Area having gentle slope rather than steep slope (slope
stability).
• Area receiving adequate rainfall.
• Area away from settlement and agricultural fields.
• Permeability of soil or type of soil.
• Water table.
• Effects on forest and wildlife.
• Earthquake faults.
• Stream flow/Watershed.
Study Area Location
• Location- Lavale, Pune, Maharashtra
• Area is enclosed between these intervals:-
(By GPS)
18° ′ . N ° ′ . E to 18° ′ . N 73° ′ . E to
18° ′ . N 73° ′ . E to 18° ′ . N 73° ′ . E .
• Construction of catchment area around Symbiosis valley.
Study Area
• Over-view of Study Area-
1. Seasonal Rainfall Pattern.
2. Study of Soil Map ,Land Use Map, HSG Map, Drainage Data
Map and Runoff Coefficient Map.
• Topographically and geographic analysis-
1. Height and depression of the area.
2. Type of Soil.
Flow chart of methodology
Soil map ASTER
DEM
Topographic Maps
& Collateral data
HSG Map Slope Map Rainfall
data
Drainage
Map
SCS-CN
Map
Runoff Coefficient
Map
Decision Rules for
water conservation
measures
Site Suitability Map for different
water conservation measures
Satellite Data
(LANDSAT)
Land Use Map
Important terms
• LANDSAT-
The Landsat program is the longest running enterprise for
acquisition of satellite imagery of Earth.
It has a resolution of 28.5m approx.
Therefore to have precise values we will be using BHUVAN
images having resolution of 0.5-1m.
LANDSAT image of Kolkata.
• Soil Map:
It determines the various types of soil in a particular area such as
clayey, desert soil etc.
• Land Use Map:
It shows the type of agriculture, forestry and settlement.
• ASTER DEM MAP:
ASTER (Advanced Space borne
Thermal Emission and Reflection
Radiometer) DEM(Digital
Elevation Map)
1. ASTER provides high-
resolution images of the planet
ranging from visible to thermal
infrared light.
2. ASTER data are used to
create detailed maps of surface
temperature of land,
emissivity, reflectance, and
elevation
Mt. ETNA
• HSG MAP- HYDROLOGICAL SOIL GROUP
It groups the soil of similar type.
• RUNOFF MAP
The amount of water lost due to turbulent flow.
• Land use - Land use involves the management and modification
of natural environment or wilderness into built environment
such as settlements and semi-natural habitats such as arable
fields, pastures, and managed woods.
Land use plans are implemented through land division and use
ordinances and regulations, such as zoning regulations.
'La d use' is a key ter i the la guage of ity pla i g.
• Land cover - Land cover is the physical material at the surface of
the earth. Land covers include grass, asphalt, trees, bare ground,
water, etc. Earth cover is the expression used by ecologist
Frederick Edward Clements that has its closest modern
equivalent being vegetation.
There are two primary methods for capturing information on
land cover: field survey and analysis of remotely sensed imagery.
• Spectral Bands- For the true color rendition, band 1 is displayed in the blue color, band 2 is displayed in the green color, and band 3 is displayed in the red color. The resulting image is fairly close to realistic - as though you took the picture with your camera and were riding in the satellite. But it is also pretty dull - there is little contrast and features in the image are hard to distinguish.
Blue- Scattered by the atmosphere and illuminates material in shadows better than longer wavelengths; penetrates clear water better than other olors; a sor ed y hlorophyll, so pla ts do ’t sho up ery rightly i this
band; useful for soil/vegetation discrimination, forest type mapping, and identifying man-made features.
Green- Penetrates clear water fairly well, gives excellent contrast between clear and turbid (muddy) water; helps find oil on the surface of water, and vegetation (plant life); reflects more green light than any other visible color; man-made features are still visible.
Red- Limited water penetration; reflects well from dead foliage, but not well from live foliage with chlorophyll; useful for identifying vegetation types, soils, and urban (city and town) features .
• Geo referencing is the process of assigning spatial coordinates
to data that is spatial in nature, but has no explicit geographic
coordinate system. Here, we will take a scanned paper USGS
topographic map and assign spatial coordinates to the image
so that it can be overlaid with modern data.
• Stream order is a method for classifying the relative location
of a reach within the larger river system.
Hydrologic Soil Group
• Soils are classified by the Natural Resource Conservation Service into four Hydrologic Soil
Groups based on the soil's runoff potential.
• Group A is sand, loamy sand or sandy loam types of soils. It has low runoff potential and
high infiltration rates even when thoroughly wetted. They consist chiefly of deep, well to
excessively drained sands or gravels and have a high rate of water transmission.
• Group B is silt loam or loam. It has a moderate infiltration rate when thoroughly wetted
and consists chiefly or moderately deep to deep, moderately well to well drained soils
with moderately fine to moderately coarse textures.
• Group C soils are sandy clay loam. They have low infiltration rates when thoroughly
wetted and consist chiefly of soils with a layer that impedes downward movement of
water and soils with moderately fine to fine structure.
• Group D soils are clay loam, silt clay loam, sandy clay, silt clay or clay. This HSG has the
highest runoff potential. They have very low infiltration rates when thoroughly wetted and
consist chiefly of clay soils with a high swelling potential, soils with a permanent high
water table, soils with a clay pan or clay layer at or near the surface and shallow soils over
nearly impervious material.
Classification of digital imagery
Supervised-
• The user selects representative samples for each land cover class in the digital image. These sample land cover classes are called training sites . The image classification software uses the training
sites to identify the land cover classes in the entire image.
• The classification of land cover is based on the spectral signature defined in the training set. The digital image classification software determines each class on what it resembles most in the training set. The common supervised classification algorithms are maximum likelihood and minimum-distance classification.
Supervised Classification Steps:
• Select training areas
• Generate signature file
• Classify
Classification of digital imagery
Unsupervised-
• Pixels are grouped based on the reflectance properties of pixels. These groupings are called clusters . The user identifies the number of clusters to generate and which bands to use. With this information, the image classification software generates clusters. There are different image clustering algorithms such as K-means and ISODATA.
• The user manually identifies each cluster with land cover classes. It’s ofte the ase that ultiple lusters represe t a si gle la d cover class. The user merges clusters into a land cover type. The unsupervised classification image classification technique is commonly used when no sample sites exist.
Unsupervised Classification Steps:
• Generate clusters
• Assign classes
Rainfall Map and Data
Site can be chosen when the rainfall in the area is above average. Since our area is quite
small and has an influence of same amount of rainfall due to presence of one rain gauge
station, the factor is not to the highest importance.
Slope Map and Data
• Steep: Steeper the slope, more is the water shed.
• Gentle: In gentle slope the water shed is less.
So a gentle slope is preferred to locate a catchment area.
Stream flow/ Watershed Map and Data
• An area or ridge of land that separates waters flowing to different
rivers, basins, or seas is known as watershed.
Land Use/Land Cover
• It is basically how the land is put into use or how has it been
covered by natural resources- agriculture, forest, water body,
settlement, etc.
Unsupervised classification using iso-data
Soil Type
Ideal soil conditions are as follows-
• Permeable
• Compressible
• Shear strength
• Particle size
• Specific gravity
• Moisture content
Permeability Test-
Aim- To determine coefficient of permeability of soil sample.
K= QL/AtH
Observation Table-
Length of sample 12.73cm
C/A of sample 78.5 sq.cm
H1 20cm
H2 27cm
Area of stand pipe 1.6 sq.cm
Test temp. 33 deg C
Time interval - 7min
- 5min
- 5min
Coefficient of permeability 2.0917x10^-2 cm/sec
Cone Penetration Test:
Aim- To determine geotechnical properties of soil.
Observation Table-
No. Of Blows Total Blows Penetration(mm.)
0 0 25
10 10 39
10 20 53
10 30 69
10 40 78
10 50 84
Density of soil by sand replacement method
Aim- To determine the density of dry soil.
Observation Table-
Data Interpretation %
distribution
Requirement criteria
Sub types
Importance
rating
Total
20 Slope Gentle 8 160
Steep 6
30
Land use/ Land cover Agriculture/Forest 7
270 Water 9
Settlement 2
20 Rainfall Cyclonic 3 160
Orographic 8
10
Soil Type Clayey 3
70 Black 5
Loamy 7
20
Watershed/Stream flow 1 9
180 2 7
3 5
Total 840
Conclusion
All the points that fulfill the criteria of slopes, land use/land cover,
rainfall, soil type, earthquake zone, water shed and water table
are combined to get one single value criteria.
The region getting fulfilled by this criteria is the spot where the
catchment can be built.
Future Scope
This work can be carried forward by improvising all the available
data and researching on earthquake zone and water table in the
years to come.
References
• Kumar GM, Agarwal AK, Rameshwar B. Delineation of potential sites for
water harvesting structures using remote sensing and GIS journal of Indian
society of remote sensing 2008;36:323-334
• Jha K Madan, Chowdary VM, Kulkarni Y., Mal BC Rainwater harvesting
planning using geospatial techniques and multi criteria decision analysis
2014;83:96-111
• www.engineeringcivil.com
• www.indiawaterportal.com
• Google Earth
• Wikipedia
• Indian Metrological Department
• www.mpcb.gov.in