龙泓涧流域景观特征及其水环境质量研究

发布时间：2018-07-01 16:24

本文选题：龙泓涧流域 + 景观特征　；参考：《华东师范大学》2015年硕士论文

【摘要】：龙泓涧是杭州西湖上游四大溪流之一,是西湖天然的补给水源。随着社会经济及旅游业的发展,龙泓涧流域出现了许多环境问题,突出表现为以氮污染为主的水环境问题。本论文依托“十二五”国家水体污染控制与治理科技重大专项“城市内湖氮磷去除及富营养化控制技术研究”课题(2013ZX07310),选取龙泓涧流域为研究对象,从保护和改善生态环境的目的出发,通过对该流域的景观特征、水环境质量进行分析,探究该流域景观-水环境的响应关系,寻求该流域生态环境的优化措施,得出以下结论：(1)龙泓涧流域的景观多样性较高,主要包括森林、茶园、水体、建筑用地和城市绿化5种景观类型。景观结构呈规律性分布,水体是最易受人类活动影响的景观类型；景观格局的多样性、均匀度、聚集度和结合度较高,破碎度较低。(2)通过“源”、“汇”景观指数来描述“源”、“汇”景观对污染物的贡献和截留情况,研究结果表明,龙泓涧流域的“汇”景观指数(HI)大于“源”景观指数(YI),说明该流域的景观对污染物的截留能力大于贡献能力,有利于污染物浓度的降低。因此,在流域尺度上该流域的景观格局有利于生态环境的改善和保护。(3)龙泓涧水质总体呈现“低碳、低磷、高氮”的特点,水质随时间变化较大,而随空间变化不大。时间上,水体中各污染物浓度随时间波动较大,以TN为例,变化范围在0.80 mg/L～21.28 mg/L之间。空间上,水体中各污染物浓度变化不大,变化主要集中在梯级塘对氮磷污染物的去除方面,梯级塘对含磷污染物的去除效果好于对含氮污染物的去除效果。(4)利用模糊数学水质综合评价方法对龙泓涧水质进行评价,结果显示龙泓涧水质在丰水期、平水期、枯水期均为劣V类。其中,TN所占的权重最大,三个水期分别为0.672、0.606、0.653。这表明龙泓涧水质的主要污染物为TN。(5)龙泓涧流域的景观结构和景观格局对水质产生不同的影响。景观格局尺度的景观指数比景观结构尺度的景观指数更能解释水质指标的某些变化,景观格局与水质的相关关系更为明显。基于以上结论,结合龙泓涧流域的具体情况,可分别从合理划分景观功能区、科学分配“源”“汇”景观格局、严格控制非点源污染3个方面对该流域的生态环境进行优化。
[Abstract]:Longhongjian is one of the four major streams in the upper reaches of the West Lake in Hangzhou, and is a natural supply water source for the West Lake. With the development of social economy and tourism, there are many environmental problems in Longhong River Basin, which are mainly caused by nitrogen pollution. Based on the "12th Five-Year Plan" national water pollution control and treatment science and technology major project, "study on nitrogen and phosphorus removal and eutrophication control technology in urban lakes" (2013ZX07310), this paper selects Longhongjian watershed as the research object. For the purpose of protecting and improving the ecological environment, through the analysis of the landscape characteristics and the water environment quality of the watershed, the response relationship between the landscape and the water environment of the basin is explored, and the optimization measures of the ecological environment of the basin are sought. The main conclusions are as follows: (1) the landscape diversity of Longhongjian watershed is high, including forest, tea garden, water body, construction land and urban greening. The landscape structure is regularly distributed, water is the most vulnerable landscape type affected by human activities, the diversity, evenness, aggregation and binding degree of landscape pattern are higher, and the degree of fragmentation is lower. (2) through "source", "sink" landscape index is used to describe the contribution and interception of "source" and "sink" landscape to pollutants. The landscape index (HI) of "sink" is larger than that of "source" (YI), which indicates that the interception ability of the landscape is larger than the contribution ability, which is beneficial to the reduction of pollutant concentration. Therefore, the landscape pattern of the watershed is beneficial to the improvement and protection of ecological environment. (3) the water quality of Longhong River shows the characteristics of "low carbon, low phosphorus and high nitrogen". The water quality changes greatly with time, but not with space. In time, the concentrations of pollutants in water fluctuate greatly with time. Taking TN as an example, the range of variation is between 0.80 mg / L and 21.28 mg / L. In space, the concentration of pollutants in the water changed little, and the change was mainly concentrated in the removal of nitrogen and phosphorus pollutants in the cascade ponds. The removal effect of cascade ponds on phosphorus pollutants is better than that on nitrogen pollutants. (4) the comprehensive evaluation method of fuzzy mathematics water quality is used to evaluate the water quality of Longhong Jian. The results show that the water quality of Longhong stream is in the periods of high water and average water. In the dry season, all of them belong to bad V class. Among them, the weight of Thunb TN is the largest, which is 0.653 in three water periods. This indicates that the main pollutant of water quality in Longhong River is TN. (5) the landscape structure and landscape pattern of Longhong River Basin have different effects on the water quality. The landscape index of landscape pattern scale can explain some changes of water quality index better than landscape structure scale landscape index, and the correlation between landscape pattern and water quality is more obvious. Based on the above conclusions, the ecological environment of Longhongjian watershed can be optimized from three aspects: rational division of landscape function area, scientific distribution of "source" and "sink" landscape pattern and strict control of non-point source pollution.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52;P901

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