Fig 1.
Map of India and West Bengal emphasizing the study area.
(Base map was prepared from Landsat 7 satellite image. Local study area boundaries were digitized from toposheets. Satellite images were downloaded from www.usgs.gov).
Fig 2.
Sampling pattern for tidal analysis.
Fig 3.
Seasonal changes of pH at five selected outfalls of river Ganga.
Fig 4.
Seasonal changes of temperature (°C) at five selected outfalls of river Ganga.
Fig 5.
Seasonal changes of DO (mg/L) at five selected outfalls of river Ganga.
Fig 6.
Seasonal changes of conductivity (μS/cm) at five selected outfalls of river Ganga.
Fig 7.
Seasonal changes of BOD (mg/L) at five selected outfalls of river Ganga.
Fig 8.
Seasonal changes of total hardness (mg/L) at five selected outfalls of river Ganga.
Fig 9.
Seasonal changes of Nitrate nitrogen (mg/L) at five selected outfalls of river Ganga.
Fig 10.
Seasonal changes of chloride (mg/L) at five selected outfalls of river Ganga.
Fig 11.
Seasonal changes of phosphorus (mg/L) at five selected outfalls of river Ganga.
Fig 12.
Seasonal changes of lead (as Pb) (mg/L) at five selected outfalls of river Ganga.
Fig 13.
Seasonal changes of mercury (as Hg) (mg/L) at five selected outfalls of river Ganga.
Fig 14.
Seasonal changes of total arsenic (as As) (mg/L) at five selected outfalls of river Ganga.
Fig 15.
Seasonal changes of total coliform (MPN/100ml) at five selected outfalls of river Ganga.
Fig 16.
Seasonal changes of fecal coliform (MPN/100ml) at five selected outfalls of river Ganga.
Table 1.
p-value of seasonal analysis of pH, temperature (°C), DO (mg/L), conductivity (μS/cm) and BOD (mg/L), total hardness (mg/L), nitrate nitrogen (mg/L), chloride (mg/L) and phosphorus (mg/L) for five selected outfalls.
Table 2.
Prediction of water quality parameters by regression equation.
Table 3.
Distance (m) at which BOD, DO, Nitrate Nitrogen, Phosphorous reaches its permissible limit during low tide at different sampling sites season wise.
Table 4.
Strip-wise depth average discharge across the river Ganga from outfall and at its upstream at Ballykhal and Dakshineswar.
Table 5.
The value of discharge at different sampling points of Dakshineswar Canal and Ballykhal during low tide and high tide.
Table 6.
The estimated and measured water quality parameters with its percentage of error at different sampling points of Ballykhal and Dakshineswar Canal during low tide and High Tide.
Fig 17.
Spatial distribution map of BOD at Dakshineswar Canal during pre-monsoon low tide (left) and pre-monsoon high tide (right).
Fig 18.
Spatial distribution map of BOD at Dakshineswar Canal during monsoon low tide (left) and monsoon high tide (right).
Fig 19.
Spatial distribution map of BOD at Dakshineswar Canal during post-monsoon low tide (left) and post-monsoon high tide (right).
Fig 20.
Spatial distribution map of DO at Dakshineswar Canal during pre-monsoon low tide (left) and pre-monsoon high tide (right).
Fig 21.
Spatial distribution map of DO at Dakshineswar Canal during monsoon low tide (left) and monsoon high tide (right).
Fig 22.
Spatial distribution map of DO at Dakshineswar Canal during post-monsoon low tide (left) and post-monsoon high tide (right).