| 引用本文: | 成晓奕,李慧赟,戴淑君.天目湖沙河水库溶解氧分层的季节变化及其对水环境影响的模拟.湖泊科学,2013,25(6):818-826. DOI:10.18307/2013.0605 |
| CHENG Xiaoyi,LI Huiyun,DAI Shujun.Modeling of seasonal vertical variation of dissolved oxygen and its impacts on water environment in Shahe Reservoir within Tianmuhu Reservoir. J. Lake Sci.2013,25(6):818-826. DOI:10.18307/2013.0605 |
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| 摘要: |
| 溶解氧(DO)是水体能否维持生态平衡的重要指标,是湖泊初级生产力与水动力条件的综合反映.研究DO及其分层的季节变化对认识湖库的富营养化过程有重要意义.本研究以天目湖沙河水库为例,运用西澳大学开发的三维水动力水质模型——ELCOM-CAEDYM对天目湖的水温、DO和总磷(TP)进行了为期1年的数值模拟.结果表明,模型较好地模拟出了水体温度和DO分层过程以及TP的时空分布,3个指标在水体表层、中层和底层的模拟值与实测值拟合良好,均方根误差分别在1.8℃、1.8 mg/L和0.003 mg/L以内,Nash-Sutcliffe有效性系数均在0.7以上,相对误差均低于10%.沙河水库不同季节的DO垂向分层与温跃层协同变化:冬季垂向混合;春季(4月)温跃层开始发育,底部出现氧不足;夏季(7月)温跃层位于4~10 m之间,同时底部低氧区(DO<2 mg/L)面积达35%;秋季(9月末)低氧区随着温跃层的消失而消失;冬季再次垂向混合.全湖DO和TP的时空分布表明,南半库区磷的来源主要是外源输入,而北半库区磷的来源主要是由水体底部低氧导致的磷内源释放.DO季节分层还有可能通过影响藻类活动而对水环境造成影响. |
| 关键词: 溶解氧 热力分层 天目湖 数值模拟 总磷 沙河水库 |
| DOI：10.18307/2013.0605 |
| 分类号: |
| 基金项目:中国科学院南京地理与湖泊研究所引进人才启动项目(NIGLAS2012QD01);中国科学院择优支持项目(YOBROB045);国家自然科学基金项目(51279194,40871095);溧阳市沙河水库管理处项目联合资助 |
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| Modeling of seasonal vertical variation of dissolved oxygen and its impacts on water environment in Shahe Reservoir within Tianmuhu Reservoir |
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CHENG Xiaoyi1,2, LI Huiyun1, DAI Shujun1,2
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1.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China;2.University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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| Abstract: |
| Dissolved oxygen (DO) is an important indicator of aquatic ecosystem health.The primary production of a lake can be reflected through DO.Study of DO and its vertical distribution is important to understand the eutrophication process of lakes and reservoirs.A three-dimensional hydrodynamic-water quality model (ELCOM-CAEDYM) developed by Center for Water Research of University of Western Australia was applied in order to provide substantial information about vertical distribution of DO at Tianmuhu Reservoir.The simulation duration is from January 1st to December 31st,2011 (365 d).The simulation results of DO,water temperature and total phosphorus (TP) showed good agreement (RMSE<1.8℃,1.8 mg/L and 0.003 mg/L respectively, NSE > 0.7,RE > 10%) with observed data,which indicated that seasonal variation of vertical distribution of dissolved oxygen changed together with thermocline.In winter water column fully mixed at Tianmuhu Reservoir.Thermal stratification started in April and the bottom area became lack of oxygen.Thermocline depth was during 4-10 m below surface with hypoxia (DO<2 mg/L) in the bottom water with an area of 35% of whole bottom area in June.When thermocline disappeared in autumn the vertically-averaged DO concentration started to increase and the water column tended to mix again.DO and TP concentration were influenced by inflows in the riverine zone while lacustrine zone was dominated by significant release resulting from hypoxic events.The vertical distribution pattern of DO induced by thermal stratification in the reservoir could further affect the water environment through algae activities. |
| Key words: Dissolved oxygen thermal stratification Tianmuhu Reservoir numerical modeling total phosphorus Shahe Reservoir |
