ABSTRACT

The distributions of nitrogen and phosphorus and the comprehensive water quality of reservoirs during freezing periods constitute weaknesses in water quality management strategies during certain periods. In this paper, ice and water samples of a typical reservoir, Biliuhe reservoir, were collected and analysed, and the comprehensive water quality was evaluated by the variable fuzzy recognition method. The results showed that the effect of ‘salt exclusion’ during ice formation was obvious, with exclusion factors of 10.54 and 1.26 for total nitrogen (TN) and total phosphorus (TP), respectively. The evaluation results showed that the comprehensive water quality of the water column and ice were 2.68 and 1.44, respectively, during the freezing period. When considering the effect of salt exclusion, the TN and TP contents in the surface water of the reservoir were 3.15 and 2.62 times the previous contents, respectively, and the evaluation results showed that the surface water quality decreased by 5%. The effect of salt exclusion during ice formation in winter mainly occurred in the top layer of the water column under ice in the deep reservoir. It is necessary to further study the influence of reservoir sediments on water quality in ice-covered water systems.

摘要

冰冻期氮磷分布及水库综合水质构成一定时期水质管理策略的薄弱环节。本文采集并分析了典型水库碧流河水库的冰水样本，并采用变量模糊识别法对水质进行综合评价。结果表明，冰形成过程中“盐排除”作用明显，总氮（TN）和总磷（TP）的排除因子分别为10.54和1.26。评价结果表明，冰冻期水柱和冰的综合水质分别为2.68和1.44。在考虑盐排除的影响时，水库地表水TN、TP含量分别为前期的3.15倍和2.62倍，评价结果表明地表水水质下降5%。冬季结冰过程中盐分排斥作用主要发生在深层水库冰下水柱的顶层。有必要进一步研究水库沉积物对冰盖水系统水质的影响。