为探究珠海市多水源供水体系下存在的水源水质问题，特别是藻类问题，采用单因子分析法评价2016—2019年珠海市4座典型水库的数项水质指标，并采用统计学方法分析水库水中藻类的时空分布特征；采用双变量分析及逐步回归分析的方法研究10项水质指标与藻密度间的相关性。基于对水质数据的分析发现:珠海市水源水存在较为突出的高藻密度及高嗅味问题，其中，藻密度从春季开始普遍出现上升，而嗅味物质的质量浓度则秋冬季达到峰值，二者存在较为明显的季节性变化。回归分析的结果表明:影响水库藻密度的主要因素有总氮、高锰酸盐指数和五日生化需氧量；影响嗅味物质产生的主要因素有氨氮、高锰酸盐指数和浊度；控制水库水体的氨氮和有机物含量可以有效减少藻类数量，改善嗅味物质的产生。建立的拟合优度较高的回归模型可以用于初步预测水库水质。通过点、面源污染的控制，调节水库水体流态，结合臭氧活性炭、紫外高级氧化等深度处理技术的应用，可以有效解决珠海市水源水存在的高藻及嗅味问题。

The water supply system in Zhuhai City presents the characteristics of multiple water sources.The Xijiang River is the main drinking water source,and various reservoirs are auxiliary water sources.The reservoirs are responsible for the important function of water storage and water diversion.The water supply system combing the river and reservoirs in Zhuhai City makes the water quality not only affected by point and nonpoint source pollution in the river basin,but also interfered by the internal source pollution in the reservoir,which leads to the difficulty in controlling the stability of the water quality.The water quality of reservoirs in Zhuhai has gradually declined in recent years,and the algae content of the water body has continued to be high.The trend of eutrophication is becoming more and more obvious.However, there is still a lack of theoretical research into the impact of complex water supply system on algae in water sources,and technical guidance for algae control is therefore difficult and highly needed. The single factor analysis was used to compare the measured data and the regulated values of national standard,which aims to evaluate the water quality of four typical reservoirs (Meixi,Zhuyin,Dajingshan and Fenghuangshan reservoirs) in Zhuhai City from 2016 to 2019.The water quality characteristics and the spatial and temporal distribution of algae density in each reservoir were analyzed by the statistical method.The correlation between algae density and 10 water quality indexes (total nitrogen,total phosphorus,5-day biochemical oxygen demand,ammonianitrogen,total organic carbon,permanganate index,dissolved oxygen,2-methylisoborneol,geosmin,and turbidity) was studied by the bivariate analysis.The stepwise regression analysis was used to study and establish a regression model for preliminarily predicting the water quality of the reservoirs,with algae density,taste and odor compounds as dependent variables,and other environmental factors mentioned above as independent variables,respectively.Considering the current operational and problems of water plans in Zhuhai City, suitable solutions for solving the algae problems were analyzed and proposed from two perspectives: pollution source control and process transformation. The water quality of the reservoirs in Zhuhai City basically conformed to the standard of Class III surface water bodies from 2016 to 2019.However,the contents of total nitrogen and total phosphorus in some reservoirs exceeded the standard.From 2016 to 2019,the average algae density in the four reservoirs were 17.90 million cells/L in Meixi reservoir,18.78 million L-1in Zhuyin reservoir,9.43 million L-1in Fenghuangshan reservoir and 108.39 million L-1in Dajingshan reservoir,respectively.Under the influence of climate and water environment quality,the increase of algae density mostly occurred in spring,while the content of taste and odor compounds in the reservoirs were higher in autumn and winter,which could reach 5 times of the maximum odor threshold.Regression analysis showed that the water quality factors affecting algae density in Zhuhai reservoir involved total nitrogen and organic matter.The permanganate index was positively correlated with algal density,while total nitrogen and 5-day biochemical oxygen demand had negative correlation with the algal density.In addition,turbidity,organic matter and ammonianitrogen may contribute to the formation of taste and odor compounds in the reservoirs.And ammonianitrogen was the dominant factor and positively correlated with geosmin.Taking the monthly mean algae density of Zhuyin reservoir as the dependent variable while total nitrogen as the independent variable,a wellfitting regression model was established (R2=0.911,P<0.001,n=9).Furthermore,taking geosmin as the dependent variable while turbidity,permanganate index ammonianitrogen as the independent variables,a well-fitted regression model was developed (R2=0.911,P<0.001,n=54). High algae density,high taste and odor substances were the main water pollution problems in Zhuhai City.Ammonianitrogen and organic matter were the key factors affecting algae density and the production of taste and odor compounds in the reservoirs,algae problems in drinking water sources in Zhuhai City can be effectively solved by source control combined with the end treatment of ozone activated carbon or other advanced treatment technologies.