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Table 1 Theme wise features, ranking & weightage

From: Identifying groundwater recharge zones using remote sensing & GIS techniques in Amaravathi aquifer system, Tamil Nadu, South India

Theme Features Rank (in words) Rank (in number) Weightage
Geomorphology Pediments-moderate Moderate 2 15
Pediments-deep Moderate 2
Pediment-shallow Low 1
Dissected plateaus Very low 1
Valley fills High 3
Bazada zone High 3
Landuse/Landcover Settlements Low 1 10
Barren land/rocky Low 1
Fallow land Moderate 2
Water body High 3
Plantation High 3
Forest Moderate 2
Vegetation Moderate 2
Wet lands High 3
Soil Clayey soil/loam Low 1 10
Silty soil Low 1
Red soil Moderate 2
Lateritic soil Moderate 2
Gravely soil High 3
Sandy loam High 3
Slope (%) <  3 Nearly levelled/Very gentle 3 15
3 to 5 Gently sloping 3
5 to10 Moderate 2
10 to 15 Moderate to steep 2
>  15 Very steep 1
Post monsoon groundwater level <  3 m bgl No space – low 1 15
>  3 & < 6 m bgl Moderate 2
>  6 & < 9 m bgl High 3
>  9 m bgl Very high 3
Geology Charnockite Low 1 10
Granitic gneiss Low 1
Banded gneissic complex/Banded migmatite Low 1
Highly weathered granitic gneiss Moderate 2
Alluvium High 3
Drainage Other regions Low 1 10
Drainage lines High 3
Weathering >  6 Low 1 15
6–10 Moderate 2
10–20 High 3
>  20 m Very high 3
  1. bgl – below ground level