嘉陵江鲁班水库氮磷时空分布特征及截留率

鲁班水库是四川省第三大水库，具有灌溉、发电、防洪的功能。针对当前鲁班水库总氮（TN）、总磷（TP）浓度超标问题，阐明水库氮（N）、磷（P）时空分布特征，量化水库TN和TP的截留量及截留率，并识别影响水库水质的关键因素。结果表明：水库TN浓度年均值为(0.65±0.22)mg/L，TP浓度年均值为(0.05±0.03)mg/L。水库对TN和TP的截留率分别为55.38%和53.66%，其中，通过灌溉调水的途径去除的TN和TP分别占水库总截留量的38.11%和40.85%。除了外源N、P输入以外，水库中藻类的生长、死亡和分解过程影响水库N、P浓度，以及水库对N、P的截留率。可通过降低外源N、P输入，同时控制水库内部藻类的生长改善鲁班水库水质。

Spatial-temporal distribution characteristics and retention efficiencies of nitrogen and phosphorus in Luban Reservoir in Jialing River

Luban Reservoir is the third largest reservoir in Sichuan Province, which plays an important role in irrigation, power generation and flood control. However, concentrations of total nitrogen (TN) and total phosphorus (TP) of the reservoir cannot achieve the water quality standard. In order to address this water quality problem, there is an urgent demand in illustrating the spatial-temporal distribution characteristics of nitrogen (N) and phosphorus (P), assessing the retention amount and efficiencies of N and P, and identifying the critical factors affecting the water quality of the reservoir. The results suggested that concentrations of TN and TP were (0.65±0.22) mg/L and (0.05±0.03) mg/L, respectively. The retention efficiencies of TN and TP by the reservoir were 55.38% and 53.66%, respectively. Irrigation and water transfer contributed 38.11% and 40.85% of TN and TP retention of the total interception of the reservoir, respectively. Apart from the external inputs of N and P in the reservoir, the growth, death and decomposition of algae in the reservoir affected the concentration of N and P and the retention efficiencies of N and P in the reservoir. Therefore, decreasing external inputs of N and P and controlling algae growth in the reservoir would effectively improve the water quality of Luban Reservoir.