Assessment of water quality of Mahanadi basin using statistical and wavelet techniques

Abstract

Statistical and wavelet analysis can be effectively applied for the trend analysis of water quality parameters. Various statistical measures of the water quality parameters biochemical oxygen demand (BOD), calcium (Ca2+), chlorine (Cl−), Dissolved Oxygen (DO), bicarbonate (HCO3−), potassium (K+), magnesium (Mg2+), sodium (Na+), pH, sulphate (SO42−) and temperature in five different sites (Basantpur, Kantamal, Kurubhata, Rajim, Sundargarh) of Mahanadi River basin has been critically diagnosed. Annual twelve-daydata of eighteen years from 2001 to 2018 are collected for these five sites from CWC, Burla. The Pearson correlation coefficient is determined to implicate inter relationship between these parameters. Current work also comprises of discrete wavelet analysis of the above water quality parameters. 1D wavelet decomposition of Daubeiches at level 5 (Db5) is considered as the best mother wavelet for the analysis. Both statistical and wavelet analysis yields quite similar results. A good positive correlation can be depicted between Ca-K, Na-Cl, and strong negative correlation is derived between temperature and DO. Significant perturbations and variations from wavelet decomposition are revealed in the DO and temperature data throughout the period as compared to the other parameters.