Geoscience Reference
In-Depth Information
Table 1.
Weightage assigned to different features of various thematic maps.
Thematic map
Related features
Symbol
Weightage
Geology
Massive granite
P(Gr)
1
Weathered gneiss
A(Gn)
3
Kankar
K
1
Geomorphology
Moderately weathered buried
BPPM
3
Shallow weathered buried pediplain
BPPS
2
Moderately weathered pediplain
PPMA
3
Shallow weathered pediplain
PPSA
2
Moderately weathered pediplain
PPM
3
Shallow weathered pediplain
PPS
2
Denudational hills
DH
1
Residual hills
RH
1
Tank body
TB
2
TOR complex with isolated hills
TC
1
Valley fill
VF
3
Rocky pediment
P
1
Slope
Nearly level
0%-1%
4
Very gentle
1%-3%
3
Gentle
3%-5%
2
Moderate
5%-10%
1
Moderate — steep
10%-15%
1
Steep
15%-35%
1
Very steep
>
35%
1
Lineament
Present
—
3
Absent
—
1
0-1 km/km
2
Drainage-density
Low density/coarse texture
4
1-2 km/km
2
Medium density/medium texture
4
2-3 km/km
2
High density/fine texture
1
3-5 km/km
2
Very high density/superfine texture
1
were then reclassified assigning suitable weightage considering favorable to
groundwater potentiality (Table 1).
2.3.
Data integration
Reclassified maps were brought into the “Raster Calculator” function of
Spatial Analyst tool for integration. A simple arithmetical model has been
adopted to integrate various thematic maps. The final map has been cate-
gorized into five, from groundwater potential point of view, as Very Good
(VG), Good (G), Moderate to Good (MG), Moderate to Poor (MP), and
Poor (P).
The groundwater potential map is shown in Fig. 2. Although, the basin
has been classified into different groundwater potential zones based on the
