Statistical Studies on the Surface Water of Some Wetlands in Nadia, West Bengal

Wetlands in Nadia District are most easily accessible source of water for various human needs such as bathing, washing, irrigation and aquaculture etc. The water quality depends on several physic-chemical parameters. It is difficult to ascribe simple straightforward reason to the deterioration of water quality in a region. The more scientific way of determining the water quality of wetlands in a region is to find correlation between different pairs of physicchemical parameters, which would help in the interpretation of the observed data, and estimation of the pollution load on a scientific basis. Six different wetlands which are used extensively by the local people in Nadia District for their living were selected in order to study the physico-chemical characteristics of surface water samples in the pre-monsoon period. All the water quality parameters were obtained with 95% CL. The pH value of all the samples was in the range 5.34 to 8.67. Total dissolved solids (TDS) and Electrical Conductivity (EC) ware found range of 50.90 mg/l to 589 and 788 to 1293 μ mho/cm. Dissolved oxygen (DO) and Biological oxygen demand (BOD) varied in the range of 7.90 to 13.2 mg/l and 1.90 to 8.4mg/l. The parameter both EC and BOD for drinking purpose were significantly correlate and BOD for outdoor bathing and irrigation purpose was significantly correlate, which was above the desirable limit in all the samples throughout the period of investigation.

Linear regression analysis was carried out considering a few representative pairs of significantly correlated parameters with 0.9< r ≤ 1.0. The predicted and observed values of some strongly correlated parameters shoed marginal deviation in different wetlands. On the basis of the findings of the present study, it is recommended that the waters in the study area should be used for drinking purpose and as well as for outdoor bathing and irrigation purpose after proper treatment and decontaminations.