丹江口水库水质空间异质性多指标监测综合分析技术及效果

为深入分析丹江口水库水质时空差异性，探索影响水质的重要因子，提供更具综合性的水质分析方法，基于5个不同观察点，监测水质理化指标和浮游细菌(真菌)群落多样性指标，并采用判别分析法、配对T检验法、直接相关和典型相关分析法进行分析。结果表明：丹江口库区5个观察点的水质在2016年和2017年分别属于良好状态和优秀或良好状态，但是判别分析法显示水质理化指标在5个观察点上整体存在显著差异；浮游细菌(真菌)群落多样性指标在5个观察点上整体存在显著差异； 5个观察点水质理化性质在2 a的2个时期上均无显著性差异，即水质营养状态无显著变化，但两者之间存在显著相关性；对丹江口库区的水质理化指标群与浮游细菌(或真菌)群落多样性指标群按照2个不同时期分别进行典型相关分析，发现水质理化指标的变化趋势与浮游细菌群落多样性指标变化趋势一致；依据所有水质理化指标和浮游真菌(或细菌)群落多样性指标进行综合判别分析，可对不同观察点进一步精细分类；通过典型相关分析发现浮游真菌(或细菌)群落多样性指标可以间接指示或反映水质变化的特点；环境因子（水质理化指标）中重要指标包括X₃(COD)、X₅(NH₃-N)、 X₇(Chl-a)和X₈(SD)；浮游细菌群落多样性重要指标包括Y₁(序列条带)、Y₂(OTU数)、Y₃(Ace指数)和Y₄(Chao1指数)；浮游真菌群落多样性重要指标包括Y₁(序列条带)、Y₂(OTU数)和Y₃(Ace指数) 。本研究采用的多指标综合分析技术较单指标逐一分析更能全面客观地反映水质变化全貌，可为完善和丰富水质环境监测数据综合分析技术手段提供一定的参考。本研究结果可为相关管理部门监测和改善南水北调中线水源区水质并制定政策提供基础数据和参考依据。

Comprehensive analysis technology of multi-index monitoring on spatial heterogeneity of water quality of Danjiangkou reservoir and its effects

In order to deeply analyze the temporal and spatial differences of water quality of Danjiangkou reservoir, confirm the important affecting factors, and provide a more comprehensive analytical method, the physical and chemical indexes on water quality and the diversity of planktonic bacteria (fungi) community were monitored based on five different observation points, and they were analyzed by discrimination analysis, paired T-test, direct correlation and canonical correlation analysis method. The results showed that the water qualities of the five observation points in Danjiangkou reservoir region belonged to good and excellent or good state in 2016 and 2017, respectively, but the discriminant analysis result showed that there were significant differences in the physical and chemical indexes of water quality among five observation points; The community diversity indices of planktonic bacteria (fungi) were also significantly different. There was no significant difference on physicochemical properties of water quality between two periods of 2 a, that is, there was no significant change in nutritional status of water quality, but there was a significant correlation between them. The canonical correlation analysis on index groups between the physicochemical properties of water quality and the planktonic bacterial (or fungal) community diversity in Danjiangkou reservoir region for two consecutive years was conducted, and the results showed that the change trend of physical and chemical index of water quality was consistent with that of planktonic bacterial(fungi) community. Based on the comprehensive discriminant analysis on all physical and chemical indices and planktonic fungi (or bacteria) community diversity indices, different observation points could be further classified. Canonical correlation analysis showed that the phytoplankton fungal (or bacterial) community diversity index could indirectly indicate or reflect the change characteristics of water quality. Environmental factors (physical and chemical indicators) contained X3(COD), X5(NH3-N), X7(Chl-a) and X8(SD), and the important indicators of planktonic bacteria(fungi) community diversity contained Y1(Sequence band), Y2 (OTU number), Y3 (ACE index) and Y4 (Chao1 index). In this study, the multi index comprehensive analysis technology could more comprehensively and objectively reflect the overall view of water quality change than single index one by one, and provided a certain reference value for perfecting and enriching the comprehensive technical means of water quality and environmental monitoring data. The research results provided the basic data and a reference for relevant management departments to monitor and improve the water quality of water resource region in the middle route project for South-to-North water transfer, as well as to formulate policies.