| 引用本文: | 张晨,宋迪迪,廉铁辉.引水结构变化对天津于桥水库磷滞留的影响分析与生态水量估算.湖泊科学,2020,32(2):370-379. DOI:10.18307/2020.0207 |
| ZHANG Chen,SONG Didi,LIAN Tiehui.The influences of the water diversion structure change on total phosphorus retention and implication for ecological flows in Yuqiao Reservoir, Tianjin. J. Lake Sci.2020,32(2):370-379. DOI:10.18307/2020.0207 |
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| 摘要: |
| 2014年南水北调中线一期工程通水后，天津市的水源结构发生变化，由单一滦河水源变为双水源.引水结构变化导致于桥水库入库水量变化，从而影响水库的总磷（TP）滞留.一般认为，入库总磷负荷随入库水量减少而降低，且水力停留时间越长，将越有利于总磷滞留，从而水库TP浓度降低.但根据统计数据发现，南水北调通水后于桥水库入库水量降低，TP负荷反而升高，水库TP浓度升高.何种TP滞留机制造成了这样的结果？本文通过分析2001-2018年间入库水量（WIN）、入库总磷负荷（TPLIN）在南水北调通水前后的变化规律，采用Vollenweider模型推求水库TP浓度和磷滞留量（RP），探讨水力停留时间（τ）对库区总磷滞留量的影响机制，并估算双水源新情势下控制于桥水库磷滞留量的生态水量.结果表明：TPLIN随WIN呈先降低后升高趋势；引水期τ与RP之间存在显著的正相关关系，随着τ增加，正相关性下降，但同时考虑非引水期和引水期τ时，RP受较小的TPLIN影响与τ呈负相关.根据上述关系推算，在双水源新情势下，为保持于桥水库中贫营养状态，控制磷滞留量为南水北调通水前水平，建议每年入库生态水量大于5亿m3，出库生态水量约为入库水量的80%，配合新建前置库工程运行将有效保障水库水源功能. |
| 关键词: 总磷负荷 水力停留时间 磷滞留 Vollenweider模型 生态水量 于桥水库 |
| DOI：10.18307/2020.0207 |
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| 基金项目:国家重点基础研发计划项目（2018YFC0407203）和国家自然科学基金项目（51679160）联合资助. |
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| The influences of the water diversion structure change on total phosphorus retention and implication for ecological flows in Yuqiao Reservoir, Tianjin |
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ZHANG Chen1, SONG Didi1, LIAN Tiehui2
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1.State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300350, P. R. China;2.Yuqiao Reservoir Administrative Bureau of Luan River-Tianjin Water Diversion Project, Tianjin 301900, P. R. China
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| Abstract: |
| After supplying water to Tianjin City by the South-to-North Water Diversion Project (SNWD) in 2014, the water source has changed from a solely source of Luanhe to two sources. The new water diversion structure changed the amount of water into the Yuqiao Reservoir, which affected the total phosphorus (TP) retention of the reservoir. It is generally agreed that the TP loadings decrease with the decreasing of the inflow water of the reservoir. The longer hydraulic retention time (τ), the more favorable to TP retention, and thus the TP concentration of the reservoir decreases. However, we found that the TP loadings increased with the decreased inflow water when water supplied by SNWD, and the reservoir TP concentration also increased. What is the TP retention mechanism causing such a result? Based on the observed inflow water (WIN) and the TP loadings (TPLIN) from 2001 to 2018, the reservoir TP concentration and TP retention (RP) were estimated by the Vollenweider model. Consequently, we estimated the ecological flows by controlling the amount of RP at the level before the SNWD. The results showed that TPLIN was non-monotonous respond to WIN. There was a significantly positive relationship between τ and RP during water diversion period. Interestingly, this positive correlation decreased with the increasing of τ. However, the RP is negatively related to τ due to lower TPLIN when considering both non-water diversion and water diversion period. Undergoing the new situation of two water sources in Tianjin City, it's feasible for maintaining oligotrophic or mesotrophic state of Yuqiao Reservoir. To control phosphorus retention, we suggest that the ecological flow into the reservoir is more than 500 million m3 every year, and the ecological outflow of the reservoir can be about 80% of the inflow. |
| Key words: Total phosphorus loading hydraulic retention time phosphorus retention Vollenweider model ecological flow Yuqiao Reservoir |
