Abstract:
Objective Contents of major anions and cations in the Jiuquxi River at the Wuyishan National Park were analyzed to unveil the spatial and temporal distributions, action mechanism, and lithological control of the surface water.
Method Thirty water samples from different river sections were collected at different hydrological periods for chemical determination. Gibbs, triangle, and endmember diagrams were applied to analyze the hydrochemical mechanism and lithological control. Principal component analysis and model calculation were applied to quantify the hydrochemical contributions.
Result The river water was weakly acidic with an average total dissolved solids (TDS) of 25.30 mg·L−1, which was well below the world average of 100.00 mg·L−1. The contents of major cations in the water ranked in the order of Ca2+＞Na+＞K+＞Mg2+, while that of anions HCO3−＞Cl−＞NO3−＞SO42−. In different hydrological periods, TDS and most of the ions were dry period＞normal period＞wet period and increased from upstream to downstream of the river.
Conclusion The hydrochemistry of Jiuquxi water in the national park was HCO3−-Ca2++Na+ type and, basically, of a rock weathering action mechanism that affected by precipitation, and to a certain extent, human activities. The rock weathering altered the hydrochemistry more on the upper reach than the middle or lower reach of the river. Precipitation affected the hydrochemistry most greatly in wet season. The lithological control on the area waters was largely weathering of carbonate and silicate rocks that contributed 58.82% of the controlling factors of the hydrochemistry.
下载: