青海典型内陆河流域地表水溶解性养分组成及分布特征

为了解青海典型内陆河地表水溶解性养分组成及分布特征,对青海巴音河、格尔木河及小柴旦湖流域地表水进行了采集,分析了地表水溶解性养分的组成及含量。结果表明:巴音河流域溶解性养分N、Si可能受水库滞留效应影响;克鲁克湖有较高的NH_4~+-N含量,主要与渔业养殖有关;格尔木河流域溶解性养分含量从上游到下游有升高的趋势,可能与流域内地形差异以及水体沿途蒸发作用有关;托素湖和小柴旦湖溶解性养分含量远远高于河流,主要与湖泊水体蒸发强烈导致的养分含量浓缩有关。研究区水体溶解性养分含量均大于受限阈值,但河流DIN/SRP 10、DSi/DIN 1,表现为N相对不足,湖泊DSi/SRP 10、DSi/DIN 1,表现为Si相对不足。主成分分析表明河流、水库以及克鲁克湖为Ⅰ～Ⅱ类水体,托素湖、小柴旦湖为Ⅴ类水体。

Composition and Distribution of Dissolved Nutrients in Surface Water of Typical Inland Rivers in Qinghai

To reveal the composition and distribution characteristics of dissolved nutrients in surface water of typical inland rivers in Qinghai, water samples were collected from Bayin River, Golmud River and Xiao Chaidan Lake, and concentrations of dissolved nutrients in water samples were analyzed. The dissolved nutrients, N and Si, in surface water of the Bayin River Basin were affected by the retention effect of reservoirs. The higher concentrations of NH₄⁺-N in Keluke Lake (KLK) were mainly related to fish-farming. The concentrations of dissolved nutrients increased from the upstream to the downstream of the Golmud River, due to the topography differences in the basin and the evaporation of water along the stream. The concentrations of dissolved nutrients in Tuosu Lake and Chaidan Lake were much higher than those in rivers, which might result from the evaporation of water. The concentrations of dissolved nutrients in the study area were much higher than the restricted thresholds, and the ratios of DIN/SRP, DSi/SRP and DSi/DIN showed that the limit nutrient was N for rivers and was Si for lakes. The principal component analysis results showed that water of rivers, reservoirs and Keluke Lake met the grade I~II water quality, water of Tuosu Lak and Chaidan Lake met the grade V water quality.