密云水库总磷收支和分布动态研究
文献类型:学位论文
作者 | 申校 |
学位类别 | 硕士 |
答辩日期 | 2015-05 |
授予单位 | 中国科学院研究生院 |
授予地点 | 北京 |
导师 | 李叙勇 |
关键词 | 总磷收支 磷滞留 EFDC模型 总磷时空分布 磷输入管理,TP budget TP retention effect EFDC model TP spacial and temporal distribution TP input management |
其他题名 | Dynamic Research on budgets and distribution of total phosphorus load in Miyun Reservoir |
学位专业 | 生态学 |
中文摘要 | 水库是人类调节和利用水资源的重要手段。磷作为水库富营养化主要的限制性因子之一,对其收支和分布动态变化的研究可为水库健康水生态的构建提供科学依据。 密云水库是北京市最大的饮用水源地,然而在北方气候干旱化和未来南水北调工程调水的影响下,其水生态演变状态并不明朗。为系统探讨密云水库中总磷(TP) 收支平衡和时空分布情况,本文主要从两方面进行研究:( 1)利用数理统计分析方法,估算库区TP收支情况,分析2002-2011年间TP的出入库质量负 荷和库区滞留量,并对TP滞留效应的影响因素进行分析,建立滞留率的估算公式;(2)利用环境流体动力学模型(EFDC_Explorer)建立水库水动 力学-水质模型,模拟分析库区TP浓度时空分布情况。主要结论如下: (1)10年来,TP的入库浓度和质量负荷主要受径量影响,最大值和峰值都出现在汛期。在2006年之后,入库负荷显著降低且维持在较低水平。TP出库与 库区水体中的负荷维持稳定,而库区滞留量与入库负荷呈现相似的降低趋势,且年均滞留率达到60%以上。不同年型间,受基流影响,TP输入负荷和滞留量在丰 水年间季节性变化明显,枯水年季节性变化则不显著。但输出负荷未呈现出显著的季节性变化。 (2)入库输入是影响库区TP滞留效应最主要的因素。库区特征也会影响TP滞留率,使水力负荷和水力停留时间不能有效表征密云水库滞留效应。上游TP负荷 与水库滞留率Rpm存在显著的回归关系,据此建立的回归公式可用于对库区TP滞留量的估算。公式显示,入库TP负荷控制在0.44 t?mon-1内,库区TP在一定统计时间内不会有滞留积累。 (3)库区水温分布呈现明显分层现象。在较温暖季节,入库口温度高于出库口,库东高于库西;在较寒冷季节,温度分布情况相反。表明水库地形对库区温度分布 有显著影响。而库区TP分布在空间上多表现为底层浓度高于表层,入库口高于出库口,库东高于库西,库边区域高于库中;时间上上表现为春季TP浓度较低,而 夏秋季浓度偏高。因此相对而言,这些区域为水库富营养化高风险区。 (4)加强对TP输入源的控制是降低库区TP滞留和富营养化风险的有效措施。“稻改旱”工程实施以来,库区内TP滞留量显著降低,上游入库负荷的减少是其 主要原因。但仍存在TP滞留和对高风险区的影响,需进一步加强对流域TP输入的管控,结合工程或非工程管理措施,以确保密云水库水质安全的重要保障。 |
英文摘要 | Reservoir is the important mean for human to regulate and utilize water resources. It is significant to guarantee its ecological healthy. Phosphorus is one of the main limiting factors of eutrophication in reservoirs. Therefore, the researches on its dynamic budget and distribution could provide scientific basis for building the healthy reservoir ecological environment. Miyun Reservoir is the largest drank water resource in Beijing. However, its water ecological evolution is not so clear due to the drier climate and the water transfer impact of South-to-North Water Diversion Project in the future. In order to discuss the total phosphorus(TP) budget and distribution systematically, this paper mainly focuses on two aspects: (1) Based on statistical analysis method, the TP budget in the reservoir, the TP input and output load as well as the retention content are evaluated between 2002~2011, then the influencing factors on TP retention effect are analyzed, and finally, the estimating formula for TP retention rate is developed; (2) The water dynamic-water quality model is built up and the TP temporal and spatial distribution in the reservoir is simulated and analyzed based on Environmental Fluid Dynamic Code (EFDC ). The main conclusions are as follows: (1) The TP input concentration and mass are mainly affected by flow. Meanwhile, the maximum and peak values are also occurring during the flood season. After 2006, the TP input load decreased and then maintained the low value. And the TP load of both output and the reservoir’s water body relatively stable during 10 years. However, the TP retention load in Miyun Reservoir has the similar trend with the input load. Its rate reached 60% per year. For different type of hydrological years, the seasonal change of TP input and retention load are more significant in high flow year than other hydrological years due to the influence of base flow. But, the output load has no obvious seasonal change during these 10 years. (2) The main influencing factor of TP retention effect is input load. In addition, the character of Miyun Reservoir is also has impacts on TP retention rate, which can explain why the Hydraulic Loading Rate(HLR) and Hydraulic Retention Time(HRT) can’t characterize the reservoir retention effect. Moreover, the significant relationship exists between TP input load through upstream and retention rate(Rpm) in Miyun Reservoir, according to which, the regression formula can be built up to estimate TP retention load in the reservoir. According to the estimating formula, TP input load should be controlled within 0.44 t?mon-1 so that the retention risk could be reduced. (3) The temperature stratification occurs obviously in the reservoir. During the warmer season, the temperature in the reservoir’s entrances is higher than which in its outlet. Meanwhile, the temperature in the east of the reservoir is higher than which in its west. However, during the colder season, the spatial temperature distribution is exactly opposite. This situation indicates that the temperature distribution is markedly affected by the reservoir terrain. For spatial TP concentration distribution, it is higher in the surface layer than bottom layer, in the reservoir’s entrances than its outlet and in the east than the west. Also, the TP concentration in the reservoir’s edge is higher than which in the middle of the reservoir. Therefore, there is high eutrophication risk on these regions with higher TP concentration. For temporal distribution, the TP concentration in spring is lower than other seasons but in spring and autumn, it is relatively high. (4) it is the fundamental measure to control the upstream TP input in order to reduce the TP mass in the reservoir. Since the “Change Paddy to Dryland” project was brought into force, the TP retention load decreased significantly. That’s because the TP input load reduced dramatically under this project.Therefore,it is important to enhance the management and control of TP input through watershed.Any effective engineering and non-engineering measures are needed to reduce the reservoirs’ phosphorus loading in order to control the TP retention and reduce the eutrophication risk in the reservoir. Then water quality safety would be enhanced based on those researches. |
源URL | [http://ir.rcees.ac.cn/handle/311016/34507] ![]() |
专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
推荐引用方式 GB/T 7714 | 申校. 密云水库总磷收支和分布动态研究[D]. 北京. 中国科学院研究生院. 2015. |
入库方式: OAI收割
来源:生态环境研究中心
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