Dear Dr. Rajendra Zolekar - I am providing a brief method, may be useful  for your work.

Groundwater Potential Zoning applying GIS and RS

Thematic maps: Preparation of thematic maps using GIS with respect to drainage texture, geomorphology, lineament density, lithology, slope, landuse etc. from the remotely sensed data (geocoded photographic as well as digitally enhanced products of IRS Satellite).

Assigning weights/modeling: Multi-Criteria Evaluation (MCE) - To determine the interclass/intermap dependency, a probability-weighted approach using Bayesian statistics may be adopted for a linear combination of probability weights (W) of each thematic map with the individual capability value (CV).

The different kinds of derived thematic maps have to be ranked in a scale of 0 to 5, based on relative contribution of each layer.  The rank of each map has to be converted to a probability weight (Wi = Ri ∕ ∑Ri).  The different features/categories of each thematic layer have also to be assigned scores in a numeric scale of 0 to 5. The assigned scores of different features/categories for each layer have to be converted to capability values (CVi = ri  ∕ ∑ri). These capability values (CVi) have to be multiplied with the respective probability weight of each thematic layer. An aggregation of these product values leads to the resultant weight map i.e. groundwater potential zones.

Ri = rank of a theme/layer, ∑Ri = total rank value of themes/layers (considered for modeling),  ri = Rank of a particular feature/category in a theme, ∑ ri  = total rank value of the features/categories of a theme/layer. 

Mathematically, this can be defined as,

GW = f (Dr, Geom, Lin, Litho, Sl, Lu), 

Where, Gw = Groundwater, Dr = Drainage, Geom = Geomorphology, Lin = Lineament, Lith = Lithology, Sl = Slope, Lu = Landuse

Groundwater potential map (GWP) can be expressed as

GWP = Σ Wi * CVi

where, GWP = Groundwater Potential, Wi = Map weight, CVi = Individual capability value.

The resultant final weight map will indicate the potentiality of groundwater occurrence in the study area. This map then may be classified into different categories of potentiality namely, Excellent, Very Good, Good, Poor etc.

Please give your feedback.

Thank you for your prompt reply...