parameters of the Yellow River. Ion concentrations
showed significantly negative correlation with river runoff,
especially for the Huayuankou Station in August,
September and October and for the Lanzhou Station in
July. The results are similar to those obtained by (Wright
& Worral 2001), who reported that conductivity and a
selection of metal ion concentrations such as Ca2+ and
Mg2+ showed an inverse relationship with river flow in
Tees estuary of the United Kingdom. It is suggested that
Ca2+ and Mg2+ are mostly sourced from dissolution of
rocks of the catchment; they enter river through base
flow input. Higher river flow will dilute the concentration
of these ions; on the contrary, lower runoff will increase
the concentration of these ions (Chen et al. 2002).
The results obtained in this research indicated that
major ion concentrations have response to the change of
river runoff.