基于GIS支持下福州城区景观格局与地表径流量关系研究

发布时间：2018-03-26 17:10

本文选题：景观格局　切入点：地表径流量　出处：《福建农林大学》2017年硕士论文

【摘要】：我国现处于城市化进程的快速发展期,城市人口快速增长和城市规模迅速扩张,造成土地利用压力剧增,改变了自然流域的土地利用/覆被类型,形成了不同于自然格局的城市格局。城市建设导致绿地面积削减严重、河湖水系生态功能被破坏和下垫面不透水面占比增加,阻碍了地表水与地下水连通性,极大改变了城市地表径流产流过程,从而带来一系列的城市环境问题。本文在对福州城区1991--2016年间土地利用变化分析基础上,借助地理信息系统(GIS)、Fragstats景观指数计算软件,应用SCS模型,探讨景观格局变化与地表径流量变化之间的关系,以期在城市化进程中为土地合理规划及利用、构建城市景观安全格局和解决洪涝灾害频发等问题提供理论支持。本文的主要研究内容和结论如下:(1)1991--2016年间,福州城区景观格局变化显著,建设用地面积大幅度增加,绿地和水域面积急剧减少,湿地在1991--2011年间呈递减趋势,2011--2016年间,湿地面积有所恢复。城区景观格局逐渐趋于高破碎度、形状复杂、连接性差和稳定均衡的方向发展。(2)应用SCS模型对福州城区地表径流变化进行模拟。首先根据福州地区水文气象数据及坡度对模型进行校正,重新率定初损值Ia与最大渗透量S的系数λ,发现当λ取值0.2时模型拟合度最好,模型效率最高;1991--2001年间、2001--2011年间和2011--2016年间,福州城区地表径流分别增加了 10.29mm、1.84mm和1.57mm,表明福州城区景观格局对地表径流的滞留作用逐渐增大。(3)景观格局指数与径流量的回归分析结果表明,景观指数中的景观密度PD、景观形状指数LSI、连接度指数CONNECT和蔓延度指数CONTAG多元组合对径流量的解释性强,R2=0.718,PD与径流量Q呈正相关函数关系,LSI、CONNECT和CONTAG与径流量Q呈负相关函数关系,其中连接度CONNECT对径流变化敏感性最强。(4)在研究基础上,结合福州城区实际情况,提出福州城区景观格局优化策略及减少城市地表产流的措施。
[Abstract]:China is now in the period of rapid development of urbanization, the rapid growth of urban population and the rapid expansion of urban scale, resulting in a sharp increase in the pressure of land use, which has changed the land use / cover type of natural watersheds. Different from the natural pattern, urban construction leads to serious reduction of green space area, destruction of ecological function of river and lake system, and increase of impermeable water surface proportion of underlying surface, which hinders the connectivity between surface water and groundwater. In this paper, based on the analysis of land use change in Fuzhou urban area from 1991 to 2016, the authors use GIS to calculate the landscape index of Fragstats. Using SCS model, the relationship between landscape pattern change and surface runoff change is discussed in order to plan and utilize land reasonably in the process of urbanization. The main contents and conclusions of this paper are as follows: from 1991 to 2016, the landscape pattern of Fuzhou urban area changed significantly, and the area of construction land increased significantly. The area of green space and water area decreased sharply, and the wetland area recovered in the period of 2011-2016. The landscape pattern of urban area gradually tended to be high degree of fragmentation and complex shape. The SCS model is used to simulate the variation of surface runoff in Fuzhou urban area. Firstly, the model is corrected according to the hydrometeorological data and slope of Fuzhou area. The coefficient 位 between the initial loss value Ia and the maximum permeability S is determined. It is found that the fitting degree of the model is the best when 位 is chosen as 0.2, and the model efficiency is the highest during the period of 1991-2011 and 2011-2016. The surface runoff of Fuzhou urban area increased by 10.29 mm 1.84 mm and 1.57 mm, respectively, indicating that the retention of landscape pattern on surface runoff gradually increased. Landscape density, landscape shape index, connectivity index CONNECT and extensibility index CONTAG in landscape index had a positive correlation function with runoff Q. There was a negative correlation function between LSI connect and CONTAG and runoff Q. The connectivity degree CONNECT is the most sensitive to runoff change. On the basis of the research, combining with the actual situation of Fuzhou urban area, the optimization strategy of urban landscape pattern and the measures to reduce urban surface runoff production are put forward.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P208;P333.1;P901

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