摘要
快速城市化导致的生态环境变化是当前城市生态环境研究的热点问题,而城市化的水环境效应则是其中的重要方向之一。本文通过梳理城市化过程对水环境效应的影响机制,总结和归纳城市不透水表面的水环境效应研究的核心内容与主要方法,指出当前城市化过程的水环境效应研究所面临的诸多难点,并对未来研究趋势进行展望。研究认为,城市化的显著特征之一是不透水表面的不断增加,以不透水表面指数(ISA)为表征的地表覆被参数日益受到城市土地利用/覆被变化研究的重视,成为城市化过程水环境效应研究的热点指标。不透水表面对水文效应的影响主要表现在两个方面,即短时间内增大降雨的径流量,长时间内增加洪水频率和径流总量。同时,不透水表面对水质的影响主要表现为增加水体的非点源污染负荷,目前的研究方法主要依靠城市水文水质监测及模型模拟,对水环境效应的影响机制方面尚缺乏对非点源污染负荷影响机制的深入研究,同时还需要进一步构建适用于城市地区的水文水质模型。可以预见,不透水表面指数将会是城市化过程水环境效应研究的重要参数,并将推动城市土地利用/覆被变化的水环境效应研究向参数简单化与精确化方向发展。
The environmental change impacted by rapid urbanization is a hot topic to global environmental change. In this area, research on water environmental effects of urbanization focuses on water quality, water quantity change and hydrological process and feedback disturbance. This paper reviews the mechanism between water environment change and urbanization, and summarizes the research issues we have face in this area, the methods we need, and how water environmental change responds to urban impervious surface. We also discuss the problems in the research of water environmental effects of urban impervious surface. Obviously, urbaniza- tion often directly changes natural land cover to impervious surface, but how to link urban land cover change with hydrological process and water quality is still a critical problem. The index of impervious surface area （ISA） was used to characterize land cover in urban area, and was a hot landscape indicator used to combine wa- ter environmental effects and urbanization processes. This paper indicates that the impacts of impervious surface on urban hydrology are mainly in two aspects. One is that it can increase the ratio of runoff and the amount of precipitation in a rainfall process in a short period, and the other is that it also can subsequently increase the high- er runoff peaks and total volume of runoff in receiving waters and decrease the lag times in a long period. Chang- ing natural land cover to impervious surface cover can obviously increase non-point pollution loadings and de- grade water quality. In many urban areas, we depend on urban hydrological and water quality monitoring to link the relationship, and use urban hydrological and water quality model to simulate the impacts. However, the mechanism of impervious surface impact on urban water environment is still not clear. To solve this critical prob- lem needs to know the impacting mechanism of non-point pollution loadings and to develop hydrological and water quality model suitable for urban areas. Overall, ISA is relatively simple for land planner and water quality administrator to use. This research indicates that ISA will be an important indicator to study water environmental effects of urbanization, and can also improve the modelling methods.
出处
《地理科学进展》
CSCD
北大核心
2011年第3期275-281,共7页
Progress in Geography
基金
农业部资源遥感与数字农业重点开放实验室开放课题项目
国家自然科学基金项目(40801066)
关键词
城市不透水表面
水文效应
水质效应
土地利用/覆被变化
impervious surface cover, water quality effect, hydrological effect, land use/cover change
