阿哈水库枯水期入库河流可溶性氮、磷含量分布特征

以贵阳市阿哈水库五条入库河流为研究对象，研究了阿哈水库枯水期入库河流水体可溶性氮、磷含量分布特征，可溶性氮组分比例及沿程变化规律。结果表明：五条入库河流水体可溶性氮、磷含量差异较大，可溶性总氮（DTN）、可溶性总磷（DTP）平均含量分别为1.71~9.74 mg/L和0.03~0.52 mg/L。蔡冲河、烂泥沟河、金钟河受人类活动影响较大，水体DTN、DTP含量较高。不同河流水体可溶性氮组分比例差异显著，受人类活动影响小的游鱼河、白岩河，其水体可溶性氮以可溶性有机氮（DON）为主，DON占DTN的比例高达94%。受人类活动影响大的蔡冲河、烂泥沟河、金钟河则相反，以可溶性无机氮（DIN）为主。不同河流氮、磷含量自上到下游沿程波动较大，人为源造成的氮、磷污染远高于自然源。金钟河的DTN、DTP年输入量分别为97.03 t、46.64 t，对阿哈水库的DTN、DTP输入贡献最大，分别达到45%和66%。

Distribution Characteristics of Dissolved Nitrogen and Phosphorus in Inflow Rivers of Aha Reservoir in Dry Season

Dissolved nitrogen and phosphorus, proportion of different dissolved nitrogen components, and the variation of NH₄⁺-N, NO₃^--N, dissolved organic nitrogen (DON), dissolved total nitrogen (DTN), and dissolved total phosphorus (DTP) in waters along five inflow rivers of Aha reservoir in Guiyang city were studied systematically in dry season. The results showed that concentration of dissolved nitrogen and phosphorus in five inflow rivers varied greatly, with average of 1.71-9.74 mg/L and 0.03-0.52 mg/L for DTN and DTP, respectively. Caichong river, Lannigou river, and Jinzhong river were greatly influenced by human activities, and had higher DTN and DTP concentrations. The proportion of different dissolved nitrogen components varied significantly in rivers, and was dominated by DON in Youyu river and Baiyan river that less affected by human activities, and the DON/DTN ratio reached up to 94%. However, dissolved inorganic nitrogen (DIN) was the main form of dissolved nitrogen in Caichong river, Lannigou river, and Jinzhong river. The nitrogen and phosphorus concentration fluctuated remarkably from upstream to downstream in different rivers, and the loading from man-made sources was much higher than that of natural sources. The annual input of DTN and DTP from Jinzhong river to Aha Reservoir was 97.03 t/a and 46.64 t/a, respectively, which contribute the most DTN and DTP inputs among inflow rivers, with a contribution of 45% and 66% to total input, respectively.