贵州三座深水水库富营养化特征对比分析研究

发布时间：2019-01-18 12:35

【摘要】：富营养化是全球环境问题,贵州地处长江和珠江上游流域,区域内水质状况直接影响着下游地区,对其水库开展富营养化特征及影响因素研究意义重大。于2012年11月(枯水期)、2013年4月(平水期)和7月(丰水期)对龙滩水库、万峰湖水库和三板溪水库进行调查研究,研究内容包括水库水体环境因子、富营养化指标及浮游动植物特征等,运用营养状态指数,综合营养指数,生物多样性指数等方法对水库进行富营养化评价分析,结果表明:(1)三座水库呈不同富营养化水平,龙滩水库富营养化水平较低,为贫营养到中营养水平;万峰湖水库为中营养到轻度富营养化水平;三板溪水库富营养化水平较高,为中营养到中度富营养化水平。不同水期富营养化特征有差异,枯水期各水库富营养化水平较低,平水期和丰水期较高;垂直断面内,枯水期各水层富营养化差异不显著,平水期和丰水期富营养化水平随水深的增加而降低,特别指出,湖下层60m水层至底层,受总磷浓度升高的影响,富营养化程度略有增加。因此,水库上层和下层富营养化程度较高,中层富营养化程度较低,从饮用水供水角度,为保证水质清洁,可考虑从中层取水。(2)三座深水水库出现水体热分层现象,枯水期均为单温跃层结构,龙滩水库、万峰湖水库、三板溪水库的温跃层分别出现60~80 m、40~60 m和50~70 m。在平水期和丰水期垂直断面内呈整体分层。通过对多因子聚类分析,枯水期各水库均分为上层和下层。平水期和丰水期多分为上层、中层和下层。热分层主导其他环境因子的分层结构,从而间接影响富营养化的分层状况。(3)浮游植物指示的富营养化水平为:三板溪水库为富营养状态,万峰湖水库为中营养状态,龙滩水库最低,为贫营养状态,评价结果与综合营养指数相符。而浮游动物指示的三座水库均为为中污型,而且在富营养化比较上与综合营养指数和浮游植物评价结果有所差别,因此,评价结果倾向于利采用综合营养指数。(4)三座深水水库表层至20 m是浮游植物最活跃的水层,也是水度、溶解氧、p H等环境因子变化最显著的水层,龙滩水库和三板溪水库的湖下层总磷污染负荷较高,季节性的水体对流使底层高浓度的营养物质扩散到上层水体,容易诱使浮游植物爆发形成水华。
[Abstract]:Eutrophication is a global environmental problem. Guizhou is located in the upper reaches of the Yangtze River and the Pearl River. The water quality in the region directly affects the downstream area. It is of great significance to study the eutrophication characteristics and influencing factors of its reservoirs. Longtan Reservoir, Wanfeng Lake Reservoir and Sanbanxi Reservoir were investigated in November 2012 (low water season), April 2013 (average water period) and July 2013 (high water period). The eutrophication index and phytoplankton characteristics are used to evaluate the eutrophication of the reservoir by means of nutritional status index, comprehensive nutrition index and biodiversity index. The results showed that: (1) the eutrophication level of three reservoirs was different, and the eutrophication level of Longtan reservoir was lower, which was from poor nutrition to medium nutrition level; The level of eutrophication in Wanfenghu Reservoir was medium to mild eutrophication, and the eutrophication level in Sanbanxi Reservoir was higher than that in Sanbanxi Reservoir, which was medium to moderate eutrophication level. The characteristics of eutrophication in different water periods are different. The eutrophication level of reservoirs in dry season is lower than that in normal and high water periods. In the vertical section, there is no significant difference in eutrophication between different water layers in the dry season, and the eutrophication level decreases with the increase of water depth in the normal and high water periods. In particular, it is pointed out that the increase of total phosphorus concentration affects the concentration of total phosphorus in the 60m water layer of the lower layer of the lake from the bottom to the bottom. The degree of eutrophication increased slightly. Therefore, the eutrophication degree of the upper and lower layers of the reservoir is higher than that of the middle layer. From the point of view of drinking water supply, in order to ensure clean water quality, we should consider taking water from the middle layer. (2) the phenomenon of thermal stratification occurs in the three deep water reservoirs. The thermocline of Longtan Reservoir, Wanfenghu Reservoir and Sanbanxi Reservoir appeared in 60 ~ 80 m ~ 40 ~ (60 m) and 50 ~ (70) m respectively in dry season. In the normal and abundant periods, the vertical section is stratified as a whole. The multi-factor cluster analysis shows that every reservoir is divided into upper layer and lower layer in dry season. The average and abundant periods are divided into upper, middle and lower layers. Thermal stratification dominates the stratified structure of other environmental factors, thus indirectly affecting the stratification of eutrophication. (3) the eutrophication level indicated by phytoplankton is: Sanbanxi reservoir is eutrophic state, Wanfeng lake reservoir is medium nutrient state, Longtan reservoir is the lowest, which is poor in nutrition, and the evaluation results are consistent with the comprehensive nutrition index. The three reservoirs indicated by zooplankton are of the middle pollution type and are different from the comprehensive nutrition index and phytoplankton evaluation results in eutrophication. The evaluation results tend to adopt comprehensive nutrition index. (4) the surface layer of three deep water reservoirs to 20 m is the most active water layer of phytoplankton, and the most significant change of environmental factors such as degree of water and dissolved oxygen (, p H). The total phosphorus pollution load of the lower layer of Longtan Reservoir and Sanbanxi Reservoir is high. Seasonal convection of water makes the high concentration of nutrients spread to the upper water, which can easily induce phytoplankton to erupt into Shui Hua.
【学位授予单位】：贵州师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X524

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