深水湖泊龙景湖磷形态组成及周年变化规律

Phosphorus Speciation and Annual Variation Pattern of Deep-water Longjing Lake

以龙景湖为研究对象,于2015年9月到2016年8月对水中不同形态的磷进行了逐月观测,分析了各形态磷的组成与含量水平及其周年动态变化情况。结果表明表层水体总磷浓度变化范围为0.04~0.17 mg/L,年平均含量为0.104 mg/L,含量水平已经较高,存在形态为颗粒磷48%,溶解活性磷37.5%,溶解有机磷14.6%。中层水体各磷形态组成与表层基本一致。底层TP浓度值为0.265 mg/L,其中颗粒磷13%,溶解活性磷75.7%,溶解有机磷11.3%。溶解活性磷浓度、分布特征和循环转化规律对湖泊水体中磷生物地球化学循环具有重大意义。总磷、溶解性磷、颗粒磷和溶解活性磷有明显的季节性波动,溶解有机磷全年维持低浓度水平,周年变化规律受到气候、水文条件、水力条件及人为干预等多重因素的影响。

Based on the monthly investigations of different phosphorus species from September 2015 to August 2016 at Longjing Lake, phosphorus speciation, concentration and its annual variation are analyzed in this paper. The results indicated that the total phosphorus （TP） concentration in surface water varied between 0. 04 and 0.17 mg/L, and the annual average was as high as 0. 104 rag/L, containing 48% particulate phosphorus （PP）, 37.5% soluble reactive phosphorus （SRP） and 14.6% dissolved organic phosphorus （DOP）. Concentrations of different phosphorus species in intermediate water were roughly the same as those of surface water. Benthic TP concentration was 0. 265 mg/L, containing 13% PP, 75.7% SRP and 11.3% DOP. The SRP concentration, distribution characteristics and pattern of circulation and conversion were of significant importance to phosphorus biogeoehemistry in lake water. There were apparent seasonal variations in TP, dissolved phosphorus （DP） , PP and SRP, while DOP concentration maintained a low level for the whole year. The annual variation pattern was influenced by multiple factors, including climate, hydrological and hydraulic conditions, and anthropogenic intervention.