Spatio-temporal variations of total nitrogen and total phosphorus in lake and inflow/outflow rivers of Lake Hongze, 2010-2019

基于2010-2019年洪泽湖湖体水质逐月监测数据，筛选出影响湖体水质的主要污染物指标为总氮（TN）和总磷（TP）；选取洪泽湖周边25条主要入湖河流和2条出湖河流在2019年10月2020年9月的监测数据，探讨河流外源性输入对不同湖体区域氮磷的影响及其水期变化规律.结果发现：①湖体TN、TP浓度长期居高不下，年均浓度范围分别在1.39~1.86、0.080~0.171 mg/L波动.主要入湖河流TN、TP时空平均浓度（1.92~5.70和0.114~0.181 mg/L），均高于同区域湖体（1.15~1.46和0.088~0.101 mg/L），其中北部入湖河流肖河、马化河和五河与临近湖区TN、TP浓度呈现显著正相关，是影响北部湖体TN、TP浓度的主要河流；南部入湖河流维桥河和高桥河是临近湖区非极端降雨期TN、TP的主要来源.②调水工程对湖体及入湖河流TN、TP浓度分布影响显著，调水期湖体沿调水方向TP浓度逐渐上升，TN浓度则呈现先降后升的趋势，南部入湖河流维桥河和高桥河TN浓度达到水期峰值，分别为10.69和9.90 mg/L.③极端降雨期入湖河流的TN、TP浓度显著高于其它水期，由于湖体对TN、TP的富集作用不同，TP浓度呈现中间高，四周低，而TN浓度呈现沿洪水流向逐渐降低的规律.;Based on the monthly monitoring data of Lake Hongze from 2010 to 2019, main pollutant indicators including total nitrogen (TN) and phosphorus (TP), which affect water quality Hongze, were studied. 25 inflow rivers 2 outgoing around selected for October 2019 September 2020, impact exogenous river input lake in different regions their period variation rules discussed. The results showed that:(1) concentration TN TP remained a high level long time. annual average fluctuates range 1.39-1.86 mg/L 0.080-0.171 mg/L, respectively. temporal spatial concentrations (1.92-5.70 0.114-0.181 mg/L) are higher than same (1.15-1.46 0.088-0.101 mg/L). Xiaohe River, Mahua River Wuhe that is significantly positively correlated with adjacent lake. Weiqiao Gaoqiao near southern contributors during non-extreme rainfall period. (2) transfer project has significant distribution body rivers. During period, gradually increased along direction, while trend first decreasing then increasing. south reached peak 10.69 9.90 (3) extreme other periods. Due enrichment effects lakes TP, was middle low it, law gradual decrease flood flow direction.