Hydro-Geochemistry of the River Water in the Jiulongjiang River Basin, Southeast China: Implications of Anthropogenic Inputs and Chemical Weathering

This study focuses on the chemical weathering process under the influence of human activities in the Jiulongjiang River basin, which is the most developed and heavily polluted area in southeast China. The average total dissolved solid (TDS) of the river water is 116.6 mg/L and total cation concentration ([Formula: see text]) is 1.5 meq/L. Calcium and [Formula: see text] followed by [Formula: see text] and [Formula: see text] constitute the main species in river waters. A mass balance based on cations calculation indicated that the silicate weathering (43.3%), carbonate weathering (30.7%), atmospheric (15.6%) and anthropogenic inputs (10.4%) are four reservoirs contributing to the dissolved load. Silicates (SCW) and carbonates (CCW) chemical weathering rates are calculated to be approximately 53.2 ton/km(2)/a and 15.0 ton/km(2)/a, respectively. When sulfuric and nitric acid from rainfall affected by human activities are involved in the weathering process, the actual atmospheric [Formula: see text] consumption rates are estimated at 3.7 × 10(5) mol/km(2)/a for silicate weathering and 2.2 × 10(5) mol/km(2)/a for carbonate weathering. An overestimated carbon sink (17.4 Gg [Formula: see text]) is about 27.0% of the [Formula: see text] consumption flux via silicate weathering in the Jiulongjiang River basin, this result shows the strong effects of anthropogenic factors on atmospheric [Formula: see text] level and current and future climate change of earth.