南水北调东线工程调水期洪泽湖水质变化规律分析

为了解南水北调东线工程调水期间洪泽湖水质变化，基于2013—2020年洪泽湖调水期水质监测数据，采用Daniel趋势检验分析水质年变化趋势，通过空间插值得出各湖区水质分布规律，并进一步用主成分分析法分析水质主要污染类型。结果表明：2013—2020年洪泽湖调水期水质在合格至轻度污染之间，TP和TN为主要超标因子；时间上水质有变好趋势，空间上过水区水质最差，但有转好趋势，而成子湖区和溧河洼区有所恶化；污染类型以富营养化污染为主，氮磷营养盐影响较大；水质污染以入湖河流输入和建设用地增加人类活动的污染为主要来源，还伴有偶发污染事故；时间上洪泽湖对东线输水的综合水质有改善趋势，建议进一步加强相关污染防治工作，保护洪泽湖水环境，保障南水北调东线工程输水水质安全。

Analysis on the water quality variation of Hongze Lake during the water transfer period of the eastern route of South-to-North Water Diversion Project

In order to understand the water quality variation of Hongze Lake during the transfer period of the South-to-North Water Diversion Project, the water quality monitoring data from 2013 to 2020 of Hongze Lake during the water transfer period was evaluated, and the evaluation results were analyzed by the Daniel trend test for the annual change trend of water quality. The spatial interpolation was done to obtain the distribution pattern of water quality in each lake area, and the main pollution types of water quality were further analyzed by the principal component analysis. The results showed that the water quality of Hongze Lake from 2013 to 2020 during the transfer period was mainly qualified and lightly polluted, with TP and TN as the main exceedance factors. The water quality tended to improve over time and spatially, the water quality in the overwater area was the worst, but there was a trend of turning better, while the Chengzihu area and the Lihewa area became deteriorated. The pollution type was mainly eutrophication pollution, and the nitrogen and phosphorus nutrients had a greater impact. The main sources affecting water quality were the discharge of pollutants from river inputs into the lake and the increase of construction land that is caused by human activities, but also accompanied by occasional pollution accidents. At the same time, in time Hongze Lake showed an improvement trend to the East Line water transmission of the comprehensive water quality, it is recommended to further strengthen the relevant pollution prevention work to protect the water environment of Hongze Lake and to protect the safety of the water quality of the east line of the South-to-North Water Diversion Project water transmission.