Figure 6
(a) The relationship between [Cl−] and [NO3 −]/[Cl−] for spatial data during the high and low season, YR indicates Yellow River; (b) The relationship between [Cl−] and [NO3 −]/[Cl−] for time series data at three selected sites. UR stands for mainstream samples at upper reaches of YR. MR means mainstream samples at middle reach of YR. LR means mainstream samples at lower reach of YR. TUR means tributaries at UR. TMR means tributaries at MR.
