汉丰湖水质时空变化及其影响因素研究

发布时间：2018-03-15 08:24

本文选题：汉丰湖　切入点：时空变化　出处：《西南大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国社会城镇化的快速发展,大量富含营养盐的物质、工农业生产产生的废水及生活污水排入湖中;同时由降雨形成的水力侵蚀将地表污染物质冲刷进入湖泊水体;加之湖泊水体流动缓慢,污染物容纳、自我净化能力相对较低,各类杂质的富集,导致水体恶化,威胁着湖泊和整个生态系统功能的安全运行。近年来,三峡库区水质健康与水质富营养化长期以来都成为社会关注的重点对象。然而,小江(澎溪河)作为长江流域的一级支流,由于人类活动、工农业发展、水土流失等带来的营养物质排入河道,给小江流域水质带来了较大的负荷,多处河段处于中营养和富营养化状态,其次级河流的水体富营养化不断威胁着三峡库区的生态环境。而汉丰湖作为小江的重要来水源头,开始于2013年进行试验性运行,并该年5月出现浮萍漂浮现象,使得该湖泊水质恶化程度加重,因此,研究并治理该湖泊已显得刻不容缓,开展对汉丰湖水污染研究对维护三峡消落区的水质安全、维持汉丰湖生态平衡与建立汉丰湖水质变化长久观察机制具有重要意义。本文结合多种多元数列统计方法与水质评价的方法,对汉丰湖成库后2013年4月～2014年3月的水质时空变化与降雨造成水土流失的特点进行了连续观察,测定了水质物理参数、营养盐与叶绿素(Chl-a)的质量浓度。在分析水质监测数据外,通过查找水污染资料与现场实际调查,联系该流域水污染与水土流失特点,得出了以下结果:(1)汉丰湖TN、TP质量浓度均超过藻类生长限值,易造成水体富营养化,应引起重视;南河Chl-a、TN、TP质量浓度高于东河;Chl-a单因子评价反映出汉丰湖水质一年中大部分时间处于中营养与贫营养状态,在冬季水质发展为富营养化;TN/TP结果表明,TN、TP分别在不同时间内制约着藻类的生长;在2013年4月～12月与2014年2月,全湖TN/TP值低于16,藻类生长受TN限制;在2014年1月、3月,TN/TP值高于16,藻类生长受TP限制。(2)在时间聚类分析上表明,可将采集水样按时间划分为三峡蓄水期和汛期,在蓄水期中水质受三峡库区蓄水影响,而在汛期中暴雨引起水质变化较大,说明水质具有时间变化特征;从空间聚类的分析结果来看分为两类,汉丰湖湖区水质在一定程度上受人为扰动程度、水文、支流水质的影响,与汉丰湖水质空间分布一致。(3)汉丰湖水质相关分析表明,Chl-a与pH、DO、NO_3~--N、TP、TN、COD_(mn)、NH4+-N呈显著正相关;COD_(mn)、TN与TP显现出极显著相关,说明该水质受到了同一污染源的影响。SD与TSS成极显著负相关,表明SD主要受到TSS的影响;通过逐步回归分析,建立了 Chl-a与水质中各相关因子的主导方程。(4)因子分析结果,说明汉丰湖呈现富营养化现象主要受Chl-a、TP、TN、NO_3~--N、DO、pH的影响,但受有机还原性污染物和TSS的干扰不可轻视。根据营养状态时间因子分析结果:①汉丰湖冬、春季均适合藻类的生长,易影起水体富营养化,夏、秋季营养化程度相对较弱,冬、春季受人为的干扰较严重;②基于时间聚类营养程度结果说明三峡蓄水引起水体营养化程度较高,要加强三峡蓄水期间富营养化防治工作,同时水土流失的影响不可轻视。③根据营养状态空间因子分析结果表明:镇东大丘污染程度最严重,水质在流向调节坝的途中,水质在进行自净;从湖区空间受污染程度表现为:南河湖心东河,东河水质较好,南河应作为主要防治对象。(5)对汉丰湖水质进行评价,该湖一年中水质达到国家地表水标准的时间约占42%,汉丰湖水体受TN、TP污染较严重;一年中汉丰湖水体在中营养～中度富营养状态之间变化,其中冬、春节富营养化较严重;受三峡蓄水的影响汉丰湖水体处于轻度～中度富营养化。(6)通过降雨与水质变化的相关分析,结果表明:半月降雨总量、半月可蚀性降雨量、半月降雨侵蚀力与水体中TN、TP质量浓度变化成显著正相关,表明该流域地表在降雨的作用下造成的水土流失与汉丰湖水体中氮磷营养盐质量浓度的增加存在显著的关系,在汛期中水土流失可造成汉丰湖水体营养程度发生变化;TN与TP成显著性正相关,说明氮磷营养盐的来源相同;汛期中汉丰湖水质受到水土流失与人为活动的双重干扰。在非汛期(三峡蓄水期间)受水土流失影响较弱。(7)通过对汉丰湖流域的自然概况、工业污染、农业污染、生活污染、内源污染的调查分析,从控制污染物排放量、加强城镇生产生活污水的排放、加强行政监督与管理、提高居民环保意识以及推进水土保持工作建设等方面提出了汉丰湖水质污染的综合治理措施。
[Abstract]:With the rapid development of social urbanization in China, a large number of rich nutrient substances, industrial and agricultural production wastewater and domestic sewage discharged into the lake; water by rainfall erosion will also form surface pollutants washed into the lake; and the lake water flow is slow, the self purification capacity of pollutants contained relatively low enrichment of all kinds of impurities the result of water deterioration, threatening the safe operation of the entire lake and ecosystem function. In recent years, the Three Gorges reservoir water quality health and water eutrophication have long become the focus of social concern. However, the Xiaojiang (Pengxi River) is a tributary of the Yangtze River Basin, as a result of human activities, the development of industry and agriculture. Soil and water loss caused by nutrients discharged into the river, brought great load to the Xiaojiang River Basin water quality, many river are in mesotrophic and eutrophic state secondary rivers The eutrophication constantly threatens the ecological environment of the Three Gorges reservoir. And Hanfeng Lake as an important water source to Xiaojiang, trial operation in 2013 this year, and in May the phenomenon of floating duckweed, water quality deterioration degree increasing, therefore, it becomes urgent to research and treatment should carry out research on Han Feng Lake. The pollution of the water quality safety of fire district maintenance of Three Gorges, plays an important role in maintaining the ecological balance and the establishment of Han Feng Lake Hanfeng lake water quality change long observation mechanism. This method combined with multivariate statistical methods and evaluation of the water quality series, on April 2013 to Hanfeng lake reservoir water and rainfall in March 2014 due to the temporal and spatial variation characteristics of soil and water loss to make continuous observation, water physical parameters determination of nutrient and chlorophyll (Chl-a) concentration. In the analysis of water quality monitoring data, through Find the water pollution data and field investigation, with water pollution and soil erosion characteristics in this basin, the following results are obtained: (1) onfull Lake TN, TP concentration exceeded the limit value of algae growth, causing eutrophication, attention should be paid to the river Chl-a, TN, TP; mass concentration is higher than that of the East River; the single factor evaluation of Chl-a reflects the Han Feng Lake water quality for most of the year in nutrition and poor nutritional status, water quality in winter for the development of eutrophication; TN/TP results showed that TN and TP respectively in different time restricts the growth of algae; in April 2013 ~ December and February 2014, the lake below TN/TP 16, algae the growth was restricted by TN; in January 2014, March, the TN/TP value is higher than 16, the growth of algae was restricted by TP. (2) showed that the time of cluster analysis, the water samples were collected according to the time is divided into three Gorges Reservoir and flood season, water quality in the storage period in the Three Gorges Reservoir Area Influence of Rainstorm in flood season, and the water quality variation caused by large, indicating that water quality varies with time characteristics; from the results of the analysis of spatial clustering is divided into two categories, Han Feng Lake water quality by human disturbance, to a certain extent affect the tributary water quality, hydrology, water quality is consistent with the spatial distribution. Hanfeng Lake (3) water camphone Lake correlation analysis showed that Chl-a and pH, DO, NO_3~--N, TP, TN, COD_ (MN), NH4+-N had a significant positive correlation; COD_ (MN), TN and TP showed significant correlation, indicating that the water quality is influenced by the same sources of.SD and TSS showed significant negative correlation, SD mainly influenced by TSS; by stepwise regression analysis, established the dominant equation of each related factor Chl-a and the water. (4) the factor analysis results, indicating Hanfeng lake eutrophication phenomenon is mainly affected by Chl-a, TP, TN, NO_3~--N, DO, pH, but by reducing organic pollutants and TSS Interference should not be underestimated. According to the results of factor analysis: the nutritional status of time Hanfeng Lake winter and spring were suitable for the growth of algae, easily caused eutrophication, eutrophication of summer, autumn winter, spring is relatively weak, affected by human interference is serious; the clustering results show that nutrition level caused by eutrophication in Three Gorges Reservoir Based on the high level, to strengthen the prevention of eutrophication in Three Gorges Reservoir during work, effects of soil and water loss. Also should not be underestimated according to the nutritional status of spatial factor analysis results show that the most serious Town Hill pollution, water quality in the flow way regulating dam, water quality in self purification; the degree of pollution from Lake space as follows: South Lake the East River, the river water quality is good, Nanhe should be used as the main control objects. (5) to evaluate the water quality of the lake water quality of Han Feng Lake, in a year to reach the national surface water standard time accounted for 42 %, Hanfeng Lake TN, TP pollution is more serious; in a year in lake nutrient ~ onfull moderate eutrophication varied between the winter spring festival, eutrophication is serious; affected by the Han Feng Lake in the Three Gorges Reservoir mild to moderate eutrophication. (6) through the correlation analysis, drop the results show that the variation of the rainfall and water quality: half of the total rainfall, half erodibility rainfall, rainfall erosivity and half water TN, variation of TP mass concentration was positively correlated, that there is a significant relationship to increase the concentration of nitrogen and phosphorus on soil erosion and water quality of the Han Feng Lake basin surface caused by rainfall under the action of in the flood season, soil erosion can cause water eutrophication degree Hanfeng lake changes; TN and TP is positively correlated, explain the sources of nitrogen and phosphorus in the same season; Han Feng Lake Water by soil erosion and human activities of the two Heavy interference. In the non flood season (Three Gorges period) by affecting soil erosion is weak. (7) the natural situation of Han Feng Lake Basin, industrial pollution, agricultural pollution, life pollution, investigation and analysis of the endogenous pollution, from the control of pollutant emissions, strengthen urban sewage production emissions, strengthen administrative supervision and management and put forward the comprehensive control measures of water pollution Hanfeng Lake aspects to improve residents' awareness of environmental protection and promote the work of construction of soil and water conservation.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X524

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