摘要
感潮河流闸门引水在有效补充内河水资源的同时也会带来较高的营养盐负荷,目前相关研究多集中于河网大尺度方面,而针对内河水质变化响应的机制尚不清晰.本研究以南通市感潮闸控河流—通吕运河为研究对象,系统阐明引水前后河流水体氮、磷等含量的时空变化特征,并对水体污染特征和富营养化程度进行评价.结果表明,通吕运河研究区水质整体为IV类,水体和沉积物总磷呈中度污染(P_(j)=0.61,S_(i)=1.16),富营养化程度为富营养(EI=60.87),且夏、秋季节的水体污染程度相对较高,水体各点位颗粒态磷含量占比平均为57.2%,氮磷比平均为5.34.引水期水体总氮含量及形态没有明显变化,而总磷、颗粒态磷含量及占比明显增加,总氮与总磷比值明显降低,溶解态氮磷比值有所增加,表明引水在一定程度上加重了水体磷限制状态.高潮位引水能够使水体由中污染恶化至重污染,引水期水体悬浮颗粒物含量、颗粒态磷和总磷含量均与流速呈显著正相关(r=0.76、0.85和0.84),表明流速(引水量)深刻影响着引水输入的颗粒物和磷含量.低潮位引水期水体仍维持在中度污染,引水输入的泥沙在下游4号点位之后即发生淤积,增加了沉积物磷污染风险.节制闸引调江水应当严格控制泥沙和磷输入量,在保证内河水位的基础上,适当降低丰水期引水量、增加枯水期泵引水量.
The water diversion of tidal rivers can not only effectively supplement the urban water resources,but also bring about large amount of nutrient load.Currently,the relevant research mainly focuses on the large-scale river network,while the direct response of water quality in urban rivers is still unclear.In the present study,the TonglüCanal,a tidal sluice-controlled river in Nantong City,is taken as the object to study the spatialtemporal variation characteristics of nitrogen and phosphorus content in the water body before and during water diversion,and assess the water pollution characteristics and eutrophication level.The results show that the water quality of TonglüCanal is in Grade IV.The water quality and sediment total phosphorus are moderately polluted,and the eutrophication level is eutrophic.The water pollution level in summer and autumn is relatively high.The average percentage of particulate phosphorus content at different site is 57.2%,and the average ratio of nitrogen to phosphorus is 5.34.During water diversion period,the percentage of particulate phosphorus content has been increased significantly,while no significant change for nitrogen.As a result,the ratio of total nitrogen and total phosphorus has been decreased significantly,while the opposite for the ratio of dissolved total nitrogen and dissolved total phosphorus.The water diversion aggravates the phosphorus limitation of the water body to a certain degree.During the high tide level diversion period,the water body is worsened from medium to heavy pollution.The content of suspended particulate matter,particulate phosphorus and total phosphorus in the water body is significantly positively correlated with the flow rate,which indicates flow rate(or diversion volume)directly determines the content of particulate matter and phosphorus imported by water diversion.During the low tide level diversion period,the water body keeps in moderately polluted,and the sediment imported by water diversion is silted up after the downstream point 4,increasing the pollution risk of sediment phosphorus.Thus,the amount of suspended sediment and phosphorus input should be strictly controlled during water diversion.In future,on the basis of ensuring the water level of the urban river,the diverted water volume during the wet season shall be appropriately reduced and the pumped water volume during the dry season shall be increased.
作者
王艳平
张伟
苗家慧
孟佳乐
陈海峰
李冬明
韩超
周向前
刘波
WANG Yanping;ZHANG Wei;MIAO Jiahui;MENG Jiale;CHEN Haifeng;LI Dongming;HAN Chao;ZHOU Xiangqian;LIU Bo(School of Geographical Science,Nantong University,Nantong 226019;Water Conservancy Project Management Office of TonglüCanal in Nantong,Nantong 226001;Nantong Branch of Jiangsu Hydrology and Water Resources Survey Bureau,Nantong 226006;Nanjing Institution of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008;Department of Aquatic Ecosystems Analysis and Management,Helmholtz Centre for Environmental Research-UFZ,Magdeburg 39114)
出处
《环境科学学报》
CAS
CSCD
北大核心
2023年第6期226-237,共12页
Acta Scientiae Circumstantiae
基金
南通市科技计划项目(No.MS12021086)
江苏省双创博士项目
南通大学科研启动金项目。
关键词
闸控河流
周期性引水
水污染评价
水质
富营养化
通吕运河
sluice-controlled river
periodic water diversion
water pollution assessment
water quality
eutrophication
TonglüCanal
作者简介
王艳平(1991-),女,博士,E-mail:wyp9107@163.com;责任作者:刘波,E-mail:lb@ntu.edu.cn。
