西江调水对珠海市供水水库富营养化的影响及其管理对策

Influence of pumping water from Xijiang River on eutrophication of water supply reservoirs and its management strategy in Zhuhai City

2006-2011年间,对西江珠海段和7座江河抽调水型水库水体总氮、总磷进行的长期监测结果发现,西江水体营养盐水平显著高于7座水库,抽调江河水导致水库营养盐水平在短期内急剧升高,水库富营养化和蓝藻水华问题凸显。7座水库总氮、总磷浓度最低的为3座中型水库:凤凰山水库、乾务水库和大镜山水库;最高的为南屏水库和竹仙洞2座小型水库,小型水库纳污、缓冲和自净能力较弱,更易受抽调来水水质的影响。设立合理的水质调度标准和构建生态工程是减缓调水水库富营养进程的有效措施。通过科学、合理的优化调度,调整水库水力滞留时间,改善水体流动性,能有效降低水库蓝藻水华发生的风险。

Total nitrogen（TN） and total phosphorus（TP） of two pumping stations and seven pumped storage reservoirs were monitored in Zhuhai City from the year of 2006 to 2011. Results showed that nutrients level of Xijiang River was significantly higher than that of the seven reservoirs. Pumping water from Xijiang River resulted in a sharp rise of nutrients level in the reservoirs in the short term,and a following cyanobacteria bloom in some reservoirs. The lowest TN and TP concentrations were detected in three middle-sized reservoirs and the highest in two small reservoirs; the main reasons were that small reservoirs showed a less buffer,self-purification and capacity of pollutant. Effective approaches to relieving eutrophication process included setting up reasonable pumping water quality standards and constructing ecological engineering. Moreover,we suggest that optimal pumping through adjusting hydraulic retention time could reduce or avoid the risk of cyanobacterial blooms.