环境地球化学国家重点实验室知识库

This study focuses on the chemical and Sr isotopic compositions of the dissolved load of the rivers in the Liao River basin, which is one of the principal river systems in northeast China. Water samples were collected from both the tributaries and the main channel of the Liao River, Daling River and Hun-Tai River. Chemical and isotopic analyses indicated that four major reservoirs (carbonates (+gypsum), silicates, evaporites and anthropogenic inputs) contribute to the total dissolved solutes. Other than carbonate (+gypsum) weathering, anthropogenic inputs provide the majority of the solutes in the river water. The estimated chemical weathering rates (as TDS) of silicate, carbonate (+gypsum) and evaporites are 0.28, 3.12 and 0.75 t/km²/yr for the main stream of the Liao River and 7.01, 25.0 and 2.80 t/km²/yr for the Daliao River, respectively. The associated CO₂ consumption rates by silicate weathering and carbonate (+gypsum) weathering are 10.1 and 9.94 × 10³ mol/km²/yr in the main stream of the Liao River and 69.0 and 80.4 × 10³ mol/km²/yr in the Hun-Tai River, respectively. The Daling River basin has the highest silicate weathering rate (TDS_sil, 3.84 t/km²/yr), and the Hun-Tai River has the highest carbonate weathering rate (TDS_carb, 25.0 t/km²/yr). The Raoyang River, with an anthropogenic cation input fraction of up to 49%, has the lowest chemical weathering rates, which indicates that human impact is not a negligible parameter when studying the chemical weathering of these rivers. Both short-term and long-term study of riverine dissolved loads are needed to a better understanding of the chemical weathering and controlling factors.