Authors

Abstract

Some selected hydrochemical parameters of Diyala river including electrical
conductivity (EC), 1
3
2 1
4
Ca+2 ,Mg+2 ,SO- ,Cl - ,HCO- , total soluble solids (T.S.S.),
discharge (Q) and total hardness(TH) were analyzed for their periodicities using monthly
measurements for the period 1993-1997, to quantify and qualify surface water and
investigate the periodicity behavior of these parameters. Results showed significant
autocorrelation for all the studied series and therefore they were subjected to the Spectral
(Fourier) analysis to investigate the main periodicities that contribute to the total
variance of the observed data. Most of the selected parameters have strong (less
frequent) semi-annual and biannual cycle, as well as seasonal cycle for, Cl, Mg, Ca, SO4,
HCO3 ,TSS , and EC. These results reveal the variation of the factors affecting the river
water quality including hydrological and meteorological conditions as well as the impact
of human activities through the river catchments river.

Keywords