滇池流域不透水表面变化的水环境效应研究

发布时间：2018-03-10 09:03

本文选题：不透水表面　切入点：滇池流域　出处：《云南师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：自1979年改革开放以来,中国城市快速发展,城市化进程不断加快,使得中国成为了全球地表覆被变化最为迅速的地区之一。随着快速城市化的推进,城市中建筑用地不断增多,不透水表面快速扩展,城市中具有较高价值的草地、湿地、水源地等日益减少,随之带来了城市内水土资源的需求与供给之间产生了矛盾。不透水表面不断增加,阻隔了城市地表的水进入到城市土壤的下垫面,甚至割断了城市地表与地下水文的之间联系,改变了区域水循环过程。不透水表面覆盖率的增加,增大了地表径流的流量和流速,使得滞后时间明显缩短,导致暴雨到达峰值的时间加快。同时在径流冲刷地表过程中大量的污染物无法沉降、吸收,通过径流过程进入受纳水体(如江河、湖泊、海峡等),导致了水体的富营养化和其他形式的污染。不透水表面的增加还会使得区域内气温升高,气候类型发生变化,间接影响了流域生态系统的生物多样性,增加了河流水体沉积物的数量以及流域自然景观的破碎度。一些工程性的措施,如河流转移、开渠、筑坝、疏通管道等,这些做法可能在短期内能解决随着不透水表面增加而带来的一系列水环境问题,但是随着时间的推移,它们只会更进一步的破坏河床和河岸栖息地(湿地),同时,随着集约土地利用的出现,产生了越来越多的污染物,而地表径流的增加使得更多的污染物进入受纳水体,产生非点源污染,最终导致水体水质下降。在过去的20多年中,随着昆明市的不断发展和建设,城市中不透水表面逐渐增加,由于地表径流的冲刷,大量的污染物随之汇入滇池,导致滇池水质不断恶化。本文以滇池流域为研究区,通过流域的数字高程模型(DEM)数据,分根据流域内河流的自然产、汇流特征,将整个滇池流域划为17个子流域,分析其不透水表面与河流水质之间的响应关系,找出两者之间的阈值,为滇池的治理和基于水质保护的城市规划提供理论支持。
[Abstract]:Since 1979, with the rapid development of Chinese cities and the acceleration of urbanization, China has become one of the most rapidly changing land cover areas in the world. With the rapid expansion of impervious surfaces and the decreasing number of high-value grasslands, wetlands and water sources in cities, the contradiction between the demand and supply of water and soil resources in the city has been brought about. Blocking the water from the urban surface from entering the underlying surface of the urban soil, cutting off the connection between the urban surface and the groundwater, changing the regional water cycle process, increasing the coverage of impermeable surface, It increases the flow rate and velocity of surface runoff, shortens the lag time obviously, and accelerates the time of rainstorm reaching its peak. At the same time, a large number of pollutants can not be deposited and absorbed in the process of runoff scouring the surface. Through the runoff process into the receiving water (such as rivers, lakes, straits, etc.), resulting in eutrophication of water and other forms of pollution. Indirectly affected the biodiversity of watershed ecosystem, increased the amount of river sediment and the fragmentation of natural landscape in river basin. Some engineering measures, such as river transfer, canal opening, dam building, dredging pipeline, etc. These practices may solve a range of water environmental problems in the short term as the impermeable surface increases, but over time they will only further damage riverbed and riparian habitats (wetlands), at the same time, With the emergence of intensive land use, more and more pollutants are produced, and the increase of surface runoff causes more pollutants to enter the receiving water body, resulting in non-point source pollution, which ultimately leads to the decline of water quality in the past 20 years or so. With the continuous development and construction of Kunming City, the impermeable surface of the city increases gradually. Due to the erosion of surface runoff, a large number of pollutants flow into Dianchi Lake, which leads to the continuous deterioration of the water quality of Dianchi Lake. In this paper, Dianchi Lake Basin is taken as the study area. Based on the digital elevation model (DEM) data, the whole Dianchi basin is divided into 17 subbasins according to the natural production and confluence characteristics of the rivers in the basin, and the response relationship between the impermeable surface and the river water quality is analyzed. To find out the threshold between the two to provide theoretical support for the governance of Dianchi Lake and urban planning based on water quality protection.
【学位授予单位】：云南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52;X143

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