| 摘要: |
| 以长兴县入太湖的泗安塘-合溪-乌溪河网为研究对象，将入湖河网划分为水源区、河网区、西苕溪区和入湖区，于2018年8月和2019年1月分别对长兴县入太湖河网丰水期和枯水期的水质状况进行了调查，采用空间聚类法、水质标识指数对水质的时空分布进行评价。结果表明，长兴入太湖河网不同片区氨氮（NH3-N）和总氮（TN）的质量浓度平均值呈现枯水期较丰水期高的特征，而高锰酸盐指数（CODMn）和总磷（TP）则呈现丰水期较枯水期高的特征。空间聚类分析结果表明，水质指标分布具有明显的空间差异性，呈现水源区>西苕溪区>河网区>入湖区的分布特征，入湖区是污染物聚集的主要区域。综合水质标识指数分析结果表明，长兴入太湖河网主要以Ⅱ类和Ⅲ类水为主；单因子水质标识指数分析结果表明，溶解氧（DO）、CODMn、NH3-N、TP指标均优于Ⅲ类水标准，TN是入太湖河网的特征污染物，且在丰水期和枯水期质量浓度平均值分别达到2.24,3.49 mg/L。因此，进一步削减氮污染是缓解其河网富营养化的关键。 |
| 关键词: 太湖 水文时期 水质评价 空间差异 聚类分析 水质标识指数 |
| DOI： |
| 分类号:X824 |
| 基金项目:国家自然科学基金资助项目(51709237)；浙江省水利科技计划项目(RC2045)；江苏省水利科技项目(2020004) |
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| Hydrological Variation Characteristics and Water Temporal spatial Difference of Taihu River Network in Changxing County |
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JI Yuyu，QIN Boqiang，ZHANG Yaolan，LI Feng，SHI Wenqing1,2,3,4
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1.Hohai University，College of Hydrology and Water Resources，Nanjing，Jiangsu 210024,China;2. Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, State Key Laboratory of Lake Science and Environment, Nanjing，Jiangsu 210008,China;3. Zhejiang Design Institute of Water Conservancy HydroElectric Power Co. Ltd., Hangzhou,Zhejiang 310002,China;4. Nanjing University of Information Science and Technology, Nanjing,Jiangsu 210044,China
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| Abstract: |
| Taking the Siantang Hexi Wuxi river network which flows into Taihu Lake in Changxing County as the research object, the river network was divided into water source area, river network area, Xitiaoxi area and lake entrance area. The water quality of Changxing Countys river network in the wet season and dry season were investigated in August 2018 and January 2019, respectively. Spatial clustering method and water quality index were used to evaluate the spatial and temporal distribution of water quality. The results showed that, in general, the mean concentrations of NH3-N and TN were higher in dry season than in wet season, while the mean values of CODMn and TP were higher in wet season than in dry season. The spatial clustering analysis showed that the distribution of water quality indexes had obvious spatial differences, showing the distribution characteristics of water source area > Xitiaoxi area > river network area > lake entrance area, and the lake entrance area were the main areas of pollutant aggregation. The analysis of comprehensive water quality identification index showed that the Changjiang River network flowing into Taihu Lake met class Ⅱ and class Ⅲ surface water quality standards. The single factor water quality identification index showed that DO, CODMn, NH3-N and TP were better than class Ⅲ surface water quality standards. TN was the characteristic pollutant into Taihu Lake network. The mean mass concentration reached 2.24 mg/L in the wet season and 3.49 mg/L in the dry season, respectively. Therefore, further reduction of nitrogen pollution was the key to alleviate the eutrophication of the river network. |
| Key words: Taihu Lake Hydrological period Water quality evaluation Spatial difference Cluster analysis Water quality identification index |
