Multivariate analysis of hydrochemical data of the groundwater in parts of Karwan – Sengar sub - basin, Central Ganga basin, India

Ganga basin is one of the world’s biggest aquifer repositories. The thick alluvium of the basin hosts
its three tier aquifer system. The aquifer of the basin is under high stress due to unethical human
intervention in the natural system. This warrants the need to evolve the basic hydrochemistry of
every bit of the basin to make a scientific planning followed by a pragmatic execution. A multivariate
statistical analysis was carried in order to give the hydrochemistry of the shallow aquifer a new
dimension which is easily understood at a glance. In the present paper an attempt has been made
to study the hydro chemical analysis data of shallow groundwater in parts of Karwan – Sengar sub
basin, Central Ganga basin. The study is made of shallow aquifer of the region in which the
movement of groundwater is from northwest to southeast. The descriptive statistical analysis was
done beside Pearson correlation, principle component and regression analysis. All these are
synthesized here to decipher the dynamics involved in the hydrochemistry of the area. The principle
component analysis identified five factors that are responsible for the data structure explaining
83.49 % of the total variance of the data set. Factor 1 to 5 explains variance of 31.23, 19.445,
13.131, 12.105 and 8.647% respectively. Regression analysis show that Electric Conductivity (EC)
as an independent variable which can be used to measure Carbonate (CO3
2-), Chloride(Cl-),
Sodium (Na+), and Total Dissolve Solids (TDS). Further Magnesium (Mg2+) can be used to calculate
the Total Hardness (TH) directly in the area.