Geoscience Reference
In-Depth Information
1.5.
Slope
Slope map of the area indicates that it varies from 0%-1% to more than
15%. We have classified the slope into five categories, i.e. 0-1, 1-3, 3-5,
5-15, and more than 15%. Most of the study area occupies slope category
of 0%-1% which is favorable for groundwater recharge.
1.6.
Geomorphology
Geomorphology reflects various landform and structural features. These
units deciphered from the remote sensing data.
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There are four major
geomorphological units namely shallow weathered pediplain (PPS), shal-
low weathered buried pediplain (BPPS), moderately weathered pediplain
(PPM) and moderately weathered buried pediplain (BPPM). The other
units such as shallow weathered pediplain with alkaline soil (PPSA), rocky
pediment (P), Tor complex (TC), Residual hills (RH), Denudational hills
(DH), and Valley fills (VF) constitute very small part of the study area.
2. Integration through GIS
The integration of various thematic maps describing favorable groundwater
zones, into a single groundwater potential map has been carried out through
the application of GIS. It required mainly three steps; Spatial Database
Building, Spatial Data Analysis, and Data Integration.
2.1.
Spatial database building
Arc Catalog tools have been used to create the scheme for feature data sets,
tables, geometric networks, and other items inside the database. The study
area boundary, drainages, villages, rivers, streams, and ponds have been
digitized from topographical map. Similarly, other maps such as geomor-
phological map, slope map, geological map, and lineament map have been
digitized from respective maps.
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These digitized maps have been projected
in polyconic projection with respect to Everest 1956. Topology building of
each map before and after projection has been carried out. Attributes to
these maps have been added. Buffering of 100 m in case of lineament map
has been adopted. Drainage density is calculated in “Spatial Analyst” tool.
2.2.
Spatial data analysis
The various thematic maps as described above were converted into raster
form considering 100 m as cell width to achieve considerable accuracy. These
