Figure 1.

Concentration-discharge relationships of major elements (Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO₃⁻, SO₄²⁻, Cl⁻, Si). The theoretical dilution curve means that these elements are diluted by deionized water (b = −1), and the theoretical dilution curve of rain water means that these elements are diluted by rain water, which is calculated by rainwater of Guiyang.