e data (IRS LISS- 
/cover and hydro- 
lable reports and 
1984-2007, water 
om Ground water 
‘astructure Corpo- 
Pollution Control 
. Drilling data of 
er formation: SOI 
survey, pump test 
je integrated with 
conventional and 
'ographical Infor- 
isive spatial and 
. subsurface of a 
database 
nodelling 
mation and high 
, canal and drain- 
ed for DEM gen- 
y area is prepared 
xf India (GSI). 
is prepared using 
ion study is done 
  
udy area 
(66.80%) out of 
28 %. Wasteland 
'aterbodies in the 
% area, Remain- 
  
ing part is built-up land both industrial and residential. Change 
detection analysis carried out in 3km buffer zone around Bandi 
river indicated areas of impact on land use/ cover particularly, 
agriculture activity — cropped area has reduced around 23.58% 
and increase in fallow land. Increase in wasteland-salt affected 
land & waterbodies by 3.86 & 3.08%, respectively. Normal- 
ised difference vegetation index found to have negative corre- 
lation with pollution level. 
Hydrogeological Map: The hydrogeological conditions of the 
terrain are depicted by the ground water potential maps, pre- 
pared by Ground Water Department, Pali. Well locations are 
plotted as GIS layer for depicting zoning pattern of water level 
and water quality. Rhyolite, granite, younger alluvium, older 
alluvium and phyllites form the major aquifer in this area. 
Borelog data have been analysed, isopach map (joining of 
similar lithologial unit) generated to get the thickness and 
multi-log 3D lithological model generated for input to hydro- 
geological boundaries in modelling. Aquifer cross section 
showing water column thickness along with strip log of bore 
wells indicating lithological horizons is shown in Figure-2. 
  
  
  
  
  
  
  
  
Figure-2 Cross section of aquifer along river Bandi 
Pollution monitoring : The pollution of ground water is a 
slow but intrinsic process and it may take years together and 
lot of efforts to regain the natural quality of the ground water, 
with analysis of existing data the variation in the spatial layer 
and database preparation of water quality and depth of well 
along the polluted river. Water quality zoning for selected pa- 
rameters of polluted water is done using data of ten wells. 
2.2.2 Ground water modelling 
Conceptual model: A conceptual model was developed based 
on the analysis of available data (litholog, GW levels, hydro- 
geomorphology, aquifer material). A multilayered structure 
based on hydrological properties was conceptualised ^ defin- 
ing the model geometry. Initial hydrological properties viz. 
three dimensional hydraulic conductivity, transmissivity, stor- 
age property (specific yield) were estimated along with time 
series rainfall, well level data. The boundary condition estab- 
lishment helped in confining the model domain. DEM as upper 
layer and Surface generated by litholog data, minimum and 
maximum water levels & maximum depth of well log formed 
the structure. Towards flow boundary, eastern boundary has 
ystalline rock (Rhyolite). North and South are having 
Streams. Bandi river flow is modelled as river. General head 
boundary condition towards Eastern part signifies dam. Trans- 
Port boundary condition in the form of rainfall recharge zones 
generated using land use, slope and vegetal cover into consid- 
eration, 
      
   
   
    
    
    
    
     
    
   
   
   
  
  
   
   
   
  
   
   
  
    
   
    
    
     
      
  
   
  
    
  
   
   
  
  
      
     
   
   
    
Numerical modelling (Flow model): Both steady state and 
transient model run for the period of 10 years (1995-2005), 
five years water level data used for calibration and rest for va- 
lidity, prediction were carried out till 2010. Steady state flow 
occurs when the magnitude and direction of flow is constant 
with time throughout the entire domain. Conversely, transient 
flow occurs when the magnitude and direction of the flow 
changes with time. This is precursor to migration study. Dur- 
ing calibration run higher calculated values are shown above 
equal calculated & observed line in the 95 confidence range for 
layer one (wells shown in red symbols) indicates model is over 
predicting. 
  
Calculated va. Observed Head : Steacy state 
uU : 
  
  
  
  
LANE rtc ee 
Figure-3 Comparison of calculated and observed well head 
Contamination migration: General migration pathways 
commonly used in investigating conceptual aquifer model are 
the floaters (immiscible contaminants), mixers (contaminants 
with uniform dissolution and movement in the aquifer), and 
sinkers (contaminants that move vertically due to density 
makeup). Copper and other heavy metals which are essential 
nutrient to plant & animal can be toxic at higher concentration. 
Initial concentration of contaminant assigned in GW modelling 
software. Advective flow model uses particle tracking based 
Eulerian-lagrangian method and explicit finite-difference 
method for dispersion. 
Fundamental difficulty in advection-dispersion modelling is 
both co-exist in transportation governing equations. While the 
miscible contaminant is transported at the same rate as that of 
ground water hydrodynamic dispersion is also governed by 
sorption property and concentration gradient of contaminant. 
Substantial part (sinkers) of the contaminant is likely to perco- 
late down was also evident during the field visits. 
Pump test & resistivity for aquifer parameters: 
Pumping test is performed to estimate specific aquifer proper- 
ties and resistivity survey carried out to get the local clay en- 
riched zone with reduced hydraulic conductivity. 
Surface geophysical method is most suitable for depth wise 
scanning of subsurface as input to distributed numerical 
model. Resistivity profiling is done to know the depth of 
weathered zone granite/rhyolite and slate/phyllite terrain.