| 引用本文: | 王昱,卢世国,冯起,刘蔚,刘娟娟,刘开清,左一锋.梯级筑坝对黑河水质时空分布特征的影响.湖泊科学,2020,32(5):1539-1551. DOI:10.18307/2020.0525 |
| WANG Yu,LU Shiguo,FENG Qi,LIU Wei,LIU Juanjuan,LIU Kaiqing,ZUO Yifeng.Effect of cascade dam construction on the spatio-temporal variations of water quality in Heihe River. J. Lake Sci.2020,32(5):1539-1551. DOI:10.18307/2020.0525 |
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| 梯级筑坝对黑河水质时空分布特征的影响 |
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王昱1,2, 卢世国1, 冯起2, 刘蔚2, 刘娟娟1, 刘开清3, 左一锋1
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1.兰州理工大学能源与动力工程学院, 兰州 730050;2.中国科学院西北生态环境资源研究院内陆河流域生态水文重点实验室, 兰州 730000;3.甘肃省讨赖河流域水资源局, 酒泉 735000
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| 摘要: |
| 为探究梯级大坝建设对河流水质变化规律的影响，将黑河上中游划分为坝上河段、坝下河段及自然河段，于2017年12月-2018年8月选取了24个主要控制断面进行水质调查，并采用多元统计的方法对比分析了不同时空尺度上的水质分布特征.结果表明：黑河上中游水质时空变化的主要影响因子为水温（WT）、pH值、溶解氧（DO）、电导率（EC）、总氮（TN）、总磷（TP）和五日生化需氧量（BOD5）.空间尺度上，WT、EC、BOD5、高锰酸盐指数（CODMn）、TN等指标具有显著性差异，其中坝上河段受BOD5、CODMn影响较大，自然河段WT、EC和TN为关键指标，而各个因子对坝下河段水质影响较小.时间尺度上，WT、EC、BOD5、氨氮与季节变化存在明显相关性，是不同河段水质时间变化的控制因子，且大多数水质因子在非汛期变化最明显.降水、温度、水文条件等季节性影响因素和梯级水库联合运用模式是该区域水质时间差异的主要原因；空间差异主要受祁连、张掖地区外源性污染物排放以及筑坝环境下水动力条件改变而产生的沉积滞留效应和沿程累积效应影响.研究表明，外源性污染源依然是导致水质变差的主要因素，梯级筑坝则是导致水质变差的间接因素.因此控制该区域人类活动所造成的外源性污染源，并针对不同种类污染物的季节变化特征实施合理的水库运行方式是改善水电梯级开发河段水质状况的关键. |
| 关键词: 水质 多元统计 时空变化 梯级大坝 黑河 |
| DOI：10.18307/2020.0525 |
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| 基金项目:国家自然科学基金项目（51669011）和甘肃省自然科学基金重大项目（18JR4RA002）联合资助. |
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| Effect of cascade dam construction on the spatio-temporal variations of water quality in Heihe River |
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WANG Yu1,2, LU Shiguo1, FENG Qi2, LIU Wei2, LIU Juanjuan1, LIU Kaiqing3, ZUO Yifeng1
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1.School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, P. R. China;2.Key Laboratory of Ecohydrology of Inland River Basin, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, P. R. China;3.Taolaihe Basin Water Resourse Authority of Gansu Province, Jiuquan 735000, P. R. China
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| Abstract: |
| Construction of casade dams in Heihe River had a certain influence on the river water quality. We divided the water into upstream and downstream reaches of dam and natural reaches. To explore the impact of casade dams on the water quality, multivariate statistical methods were used to analyze the spatio-temporal characteristics of water quality based on 24 different sampling sites from december 2017 to august 2018. The results showed that the main impact factors on water quality in Heihe River were water temperature (WT), pH, dissolved oxygen (DO), electrical conductivity (EC), total nitrogen (TN), total phosphorus (TP) and biochemical oxygen demand (BOD5). WT, EC, BOD5, chemical oxygen demand (CODMn) and TN varied signnificantly on the spatial scales. The water quality of the upstream reaches of dam were greatly affected by BOD5 and CODMn, while WT, EC and TN were the key drivers for the natural reaches and less environmental influence on the downstream water quality. In temporal terms, WT, EC, BOD5 and ammonia nitrogen excerted the greatest effects on the water quality, with most of the water quality factors changed obviously in non flood seasons. Factors such as temperature, rainfall, hydrological conditions and the joint operation mode of cascade reservoirs were the main factors affecting the seasonality of water quality in the region. The spatial differences were mainly influenced by the exogenous pollutants discharging in Qilian and Zhangye areas, and the influence of sediment retention and accumulation on the environment of dam construction due to the change of hydrodynamic conditions. The results show that exogenous pollution sources were still the main factors, followed by the cascade dam construction as the indirect factors, for the water quality deterioration. Therefore, controlling the exogenous pollution sources caused by human activities in the region, and implementing a reasonable reservoir operation mode according to the seasonal variation of pollutants were the key to improve the river water quality along with the cascade hydropower development. |
| Key words: Water quality multivariate analysis spatio-temporal variation cascade dams Heihe River |
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