Spatial variations of storm runoff pollution and their correlation with land-use in a rapidly urbanizing catchment in China

The composition of land use for a rapidly urbanizing catchment is usually heterogeneous, and this may result in significant spatial variations of storm runoff pollution and increase the difficulties of water quality management. The Shiyan Reservoir catchment, a typical rapidly urbanizing area in China, is chosen as a study area, and temporary monitoring sites were set at the downstream of its 6 sub-catchments to synchronously measure rainfall, runoff and water quality during 4 storm events in 2007 and 2009. Due to relatively low frequency monitoring, the IHACRES and exponential pollutant wash-off simulation models are used to interpolate the measured data to compensate for data insufficiency. Three indicators, event pollutant loads per unit area (EPL), event mean concentration (EMC) and pollutant loads transported by the first 50% of runoff volume (FF50), were used to describe the runoff pollution for different pollutants in each sub-catchment during the storm events, and the correlations between runoff pollution spatial variations and land-use patterns were tested by Spearman's rank correlation analysis. The results indicated that similar spatial variation trends were found for different pollutants (EPL or EMC) in light storm events, which strongly correlate with the proportion of residential land use; however, they have different trends in heavy storm events, which correlate with not only the residential land use, but also agricultural and bare land use. And some pairs of pollutants (such as COD/BOD, NH₃-N/TN) might have the similar source because they have strong or moderate positive spatial correlation. Moreover, the first flush intensity (FF50) varies with impervious land areas and different interception ratio of initial storm runoff volume should be adopted in different sub-catchments.     

Effects of climate change on the wash-off of volatile organic compounds from urban roads

The predicted changes in rainfall characteristics due to climate change could adversely affect stormwater quality in highly urbanised coastal areas throughout the world. This in turn will exert a significant influence on the discharge of pollutants to estuarine and marine waters. Hence, an in-depth analysis of the effects of such changes on the wash-off of volatile organic compounds (VOCs) from urban roads in the Gold Coast region in Australia was undertaken. The rainfall characteristics were simulated using a rainfall simulator. Principal Component Analysis (PCA) and Multicriteria Decision tools such as PROMETHEE and GAIA were employed to understand the VOC wash-off under climate change. It was found that low, low to moderate and high rain events due to climate change will affect the wash-off of toluene, ethylbenzene, meta-xylene, para-xylene and ortho-xylene from urban roads in Gold Coast. Total organic carbon (TOC) was identified as predominant carrier of toluene, meta-xylene and para-xylene in < 1 μm to 150 μm fractions and for ethylbenzene in 150 μm to > 300 μm fractions under such dominant rain events due to climate change. However, ortho-xylene did not show such affinity towards either TOC or TSS (total suspended solids) under the simulated climatic conditions.     

Experimental study on the effects of LID measures on the control of rainfall runoff

ABSTRACT

Low impact development (LID) measures are important for controlling pollution and reducing the rainfall runoff volume, but they need lots of experiments to determine optimal characteristics. This study established low-elevation greenbelts, permeable pavements, and green roofs to determine the effect of LID measures on the control of rainfall runoff in a lateritic red soils region by simulating rainfall or runoff, and the variables were mainly of grass type, pavement type, substrate thicknesses, and rainfall intensity. The results (43.54–94.00% volume reduction and 40.59–97.48% pollutant removal effectiveness of low-elevation greenbelt with 10 cm depth and 5 cm height gullies, 13.19–74.20% volume reduction and 64.04–99.90% pollutant removal effectiveness of permeable pavement with 36.4 cm thick graded gravel layer, and 8.63–24.40%, 19.22–37.26%, and 30.14–48.44% volume reduction respectively of green roofs with 30, 50, and 70 mm substrate thicknesses) implied that LID measures can effectively reduce rainfall runoff volume and pollutants in lateritic red soils regions.     

居住区冬夏绿视率与绿视因子相关性研究

居住区景观影响居民身心健康,而绿视率对评价景观的健康功能以及指导其改造规划都具有重要意义.选取杭州市内23个小区,共607个视点获取全景绿视率.首次使用冬夏绿视率和绿视率年差值的概念,并纳入绿视因子组间差异性比较以探究绿视率影响机制.研究表明:1)高层住宅具有更高水平绿视率;绿化投入影响的房价差异能够衡量居住区绿视率水...     

如何优化城市住区绿地布局形态管理场地雨洪？ ——基于重庆某住区的模拟实证研究

国内外学者针对雨水管理目标下的 城市住区场地设计展开了较多研究,但对住 区绿地系统的形态特征和径流控制的定量关 系还缺乏相关探讨。研究对住区绿地形态特 征与径流水系特征进行归纳分类,然后选择 Uwater Drainage作为场地场次降雨径流的 模拟软件,基于重庆某住区设计方案展开降 雨径流的实证模拟研究。研究了住区建筑布 局与绿地形态对降雨径流的影响特征,探索 了整合雨水管理功能的住区绿地系统复合结 构。通过将雨水管理目标融入住区规划设计 阶段,有利于住区更加有效地实现雨水管理 目标。     

基于 PCSWMM 模型的广州典型社区海绵化改造水文效应研究

随着城市化进程加快和海绵城市建设的不断推进，低影响开发（LID）措施在城市建设中备受重视。为评估LID措施效果，构建研究区域PCSWMM模型，模拟分析重现期分别为0.5、1、2、5、10和20年的设计降雨情形下LID 设施的水文效应，结果表明下凹式绿地、绿色屋顶和透水铺装等LID措施的不同组合方案对径流量和污染物均有不同程度的削减能力，且削减效果随着降雨重现期增大而减少，同时设置下凹式绿地、绿色屋顶和透水铺装的组合能达到最佳削减效果，对径流量、BOD5、CODCr、TSS、NH3-N、TN和TP的最大削减率分别为64.77%、56.93%、57.44%、51.20%、51.91%、55.29%和71.37%。     

基于ENVI-met模拟的不同用地类型居住小区绿地布局对PM2.5的影响

居住区绿地作为城市绿地的主要组成肌理,对改善空气质量起着重要作用。首次将ENVI-met用于居住小区绿地布局与PM2.5的模拟,选取武汉市典型的一类、二类、三类小区,定量分析不同草地、乔木布局对PM2.5的影响。研究表明,集中型的草地布局、四周型的乔木布局能更有效降低小区PM2.5浓度;分散型的草地布局、集中型的乔木布局最不利于消减PM2.5;四周型的乔木布局对阻滞道路上PM2.5的扩散效果最佳。同种绿地布局形式下,二类小区的平均PM2.5浓度最低,三类小区最高,PM2.5空间分布在3类小区中也具有一定的差异。研究揭示了居住小区绿地布局对PM2.5的影响机制,为小区绿地的规划设计实践提供一定参考。     

Characteristics of washed-off pollutants and dynamic EMCs in parking lots and bridges during a storm

Given the importance of water quality in drinking water sources, the Korean Ministry of Environment is designing and instigating the total maximum daily load (TMDL) program for major large rivers. For the successful implementation of this program, nonpoint pollutants resulting from various land uses should be controlled. Especially, paved areas such as parking lots and bridges are stormwater intensive land uses because of their high imperviousness and high pollutant mass emissions from vehicular activity. Vehicle emissions from these paved areas include various pollutants such as heavy metals, oil, grease and particulates. This research was conducted to investigate the magnitude and nature of the stormwater emissions with the goal of quantifying stormwater pollutant concentrations and mass emission rates from a parking lot and a bridge. Two monitoring sites in Kongju city were equipped with an automatic rainfall gauge and an automatic flow meter for measuring rainfall, water quality and runoff flow. This study presents the concentration changes during storm occurrence and event mean concentrations (EMCs) in the parking lot and bridge. The first flush criteria, a new concept explaining the relationship between EMC and the first flush effect, is also suggested using dynamic EMCs.     

国内外住区空间环境对居民健康影响研究综述

住区作为城市基本单元,良好的规划建设在改善人居环境和引导居民的健康生活习惯上具有基石作用,为深入解析住区外部空间环境对居民的健康影响,促进公众健康,追踪梳理了国内外相关主题文献,辨析了住区空间对居民健康影响的要素系统和影响路径,归纳了用地与设施、空间形态、交通与街道、绿色空间四类空间要素对居民健康的影响,发现相关健康影响并非仅是简单的正负线性相关,还存在显著的地域差异、多因素影响特征和阈值非线性相关性,进而探讨了相关研究的结论与方法在住区规划建设过程中的运用。     

Analysis of the build-up of semi and non volatile organic compounds on urban roads

Vehicular traffic in urban areas may adversely affect urban water quality through the build-up of traffic generated semi and non volatile organic compounds (SVOCs and NVOCs) on road surfaces. The characterisation of the build-up processes is the key to developing mitigation measures for the removal of such pollutants from urban stormwater. An in-depth analysis of the build-up of SVOCs and NVOCs was undertaken in the Gold Coast region in Australia. Principal Component Analysis (PCA) and Multicriteria Decision tools such as PROMETHEE and GAIA were employed to understand the SVOC and NVOC build-up under combined traffic scenarios of low, moderate, and high traffic in different land uses. It was found that congestion in the commercial areas and use of lubricants and motor oils in the industrial areas were the main sources of SVOCs and NVOCs on urban roads, respectively. The contribution from residential areas to the build-up of such pollutants was hardly noticeable. It was also revealed through this investigation that the target SVOCs and NVOCs were mainly attached to particulate fractions of 75-300 μm whilst the redistribution of coarse fractions due to vehicle activity mainly occurred in the >300 μm size range. Lastly, under combined traffic scenario, moderate traffic with average daily traffic ranging from 2300 to 5900 and average congestion of 0.47 were found to dominate SVOC and NVOC build-up on roads.     

Mathematical interpretation of pollutant wash-off from urban road surfaces using simulated rainfall

In the context of stormwater quality modelling, an in-depth understanding of underlying physical processes and the availability of reliable and accurate mathematical equations, which can replicate pollutant processes are essential. Stormwater pollutants undergo three primary processes, namely, build-up, wash-off and transport, before accumulating into receiving waters. These processes are expressed mathematically by equations in stormwater quality models. Among the three processes, wash-off is the least investigated. This paper presents the outcomes of an in-depth investigation of pollutant wash-off processes on typical urban road surfaces. The study results showed that a storm event has the capacity to wash-off only a fraction of pollutants available and this fraction varies primarily with rainfall intensity, kinetic energy of rainfall and characteristics of the pollutants. These outcomes suggest that the exponential equation commonly used for mathematically defining pollutant wash-off would need to be modified in order to incorporate the wash-off capacity of rainfall. Consequently, the introduction of an additional term referred to as the 'capacity factor'C(F) is recommended. C(F) primarily varies with rainfall intensity. However, for simplicity three rainfall intensity ranges were identified where the variation of C(F) can be defined. For rainfall intensities less than 40mm/h, C(F) varies linearly from 0 to 0.5. For rainfall intensities from 40 to around 90mm/h, C(F) is a constant around 0.5. Beyond 90mm/h, C(F) varies between 0.5 and 1.     

后疫情时代武汉住区绿地健康景观 调研及建设思考

新型冠状病毒(COVID-19)肺炎疫情引发了人们对公共健康深层次的思考。为了解武汉市居民对住区绿地景观与公共健康关系的认识、疫情前后住区绿地使用变化,以及对住区绿地健康景观建设的建议,2020年7—8月课题组开展了针对上述问题的调研。筛选武汉市2020年2月居家隔离期间15个首批“高风险”小区作为样本,采用“线上问卷+线下观察访谈”相结合的调研方法,发现:1)疫情前后,针对居民使用住区绿地的“频率”和“时长”,选择“增加”与“减少”的人数相当,与“无变化”人数比例近3:3:4;2)超半数居民解封后在住区绿地停留15min以上;3)住区绿地健康景观提升主要依托“绿地植物应用”和“健身设施及场所建设”;4)居民相对更喜欢开花的园林植物,并表现出了较明确的关于植物颜色、香型等的偏好。建议住区绿地健康景观应“关注住区弱势群体”需求,增加居民“全健康”效益,鼓励公众参与。最后指出研究的不足,并提出住区绿地健康效益有待全社会的关注和智慧贡献。     

多尺度绿地景观格局对滞蓄能力的影响研究

城市绿地系统作为构建城市海绵系统中的重要组成要素,通过优化绿地景观格局以提升城市整体滞蓄能力的方式更符合可持续发展的要求.以沈阳市三环内建成区为研究范围,利用景观格局指数方法,对城区、场地2个研究尺度的绿地景观格局进行评价,并利用相关性分析与回归分析等数理统计方法对2个研究尺度的绿地景观格局与内涝风险之间的关系进行分析...     

公园绿地与居住用地的空间耦合模式及影响 因素——以南京为例

深入探测公园绿地与居住用地的空间耦合模式及影 响因素,是高效协同两者发展、营造高品质人居环境的基础。 结合土地利用、POI等多源数据,借助空间聚类分析、地理 探测器等方法,基于南京主城区街道单元,系统揭示2006、 2012、2017、2020年公园绿地与居住用地的空间耦合模 式,并探究其影响因素。结果表明：1)公园绿地的规模增长滞 后于居住用地,古城区格局稳定,主城边缘变化突出;2)公 园绿地与居住用地的空间聚集趋势波动性减弱,形成高水平耦 合、低水平耦合、公园绿地主导、居住用地主导4种空间耦合 模式;3)空间耦合受自然条件的核心支撑、规划政策的关键导 向、邻里特征的辅助催化作用。相关规律有助于深化公园绿地 与居住用地的空间耦合理论,为城市宜居环境规划与建设提供 科学依据。     

城市住区空间安全防卫规划与设计

在城市住区里,应如何通过物质环境规划与设计,制造“防卫空间”来阻却犯罪,确保住区安全,作者提出了自己的观点。并针对住区、组团宅间、住宅外部及住区智能安全设计等几个方面作了相关的设计探讨。     

乌鲁木齐市居住区木本植物物种多样性调查研究

居住区绿地是城市园林绿地系统的组成部分,研究居住区植物多样性可为城市生物多样性保护提供基础数据。采用典型抽样法,对乌鲁木齐市具代表性的居住区的木本植物物种多样性进行了分析研究。结果表明:4个居住区共有26科47属88种木本植物。从居住区绿地的乔、灌层分析比较得出,居住区乔木层物种组成结构复杂;灌木层物种多样性指数、均匀度指数相对较低,物种多样性仍有较大的提升空间;从居住区的4种绿地类型来看,公共绿地的物种多样性水平较高,道路绿地的物种多样性水平最低;在居住区树种的选择上,野生观赏植物资源的应用未得到重视。     

发展城市屋顶绿化的政策困境与出路

通过屋顶绿化扩大城市绿色空间和绿色面积,是改善城市生态环境的重要途径。大面积推广城市屋顶绿化,对缓解我国城市化进程中日趋突出的生态恶化、土地存量骤减、“热岛效应”等问题,无疑是一种现实而有效的应对之策,在当前建设资源节约型、环境友好型社会的新形势下加快发展屋顶绿化事业对缓解城市绿化用地紧张、改善城市空间环境等方面具有重要的意义。     

基于交通因素的日常生活圈环境健康出行 适老化研究——以南京市中心城区为例

15min生活圈能够提升老年人群健康安全的生活质量。老年人群与城市绿地的连接既依赖道路体系，又面临空气污染隐患。基于大数据与ArcGIS平台，从绿地可达性视角展开对南京市中心城区“绿-居-人”体系的空间分布研究。从健康出行视角综合判断绿地规划、可达便利与老年人群的呼吸健康。研究发现如下。1)老城区中50岁及以上的人口占比(4.23%)高于新城区(2.86%),1997年及之前的老旧小区面积占比高达64%。2)老城区有67%的居住区在绿地15min步行范围内，是新城区的2倍多。以老城区为中心向外辐射，绿地对老年人群的服务效能逐级降低。3)老城区绿地受到的道路空气污染压力约为新城区的2倍。可达性高的绿地，所受道路污染源影响也更大。主干道对绿地空气污染压力的源头供给占40%，对绿地可达性的支持达33%。提倡为老年人群出行构建健康绿色路网，满足绿地15min可达和低空气污染。研究成果对城市更新中统筹绿地、路网、居住区布局，优化生活圈适老化环境具有一定借鉴价值。     

Research on the Greening Rate and Spatial Differences of Urban Residential Neighborhoods in Shenzhen

Residential green spaces are one of the most frequently used urban green space types. Aiming at filling a gap in the existing greening indicators with considerations on the spatial differences of residential green spaces, as well as to inform the improvement of urban green space service, three greening indicators, i.e. residential unit’s green coverage rate, green view index, and park ratio within a 500 m service radius, are proposed in this paper. This study selects 14,196 residential units in built area of Shenzhen City in 2017 to measure the greening rate and the geographic spatial factors of the units upon multi-sourced geographic databases such as land cover maps and street view images. The research reveals that: 1) the three indicators can all independently measure the greening rate within or around residential units; 2) the studied residential units are low in residential unit’s green coverage rate and park ratio within a 500 m service radius, but high in green view index; 3) there are significant disparities of the greening rate and the surrounding parks in 500 m service radius among the studied units, and among different housing property rights, showing a disequilibrium in green space service; and 4) the greening rate of residential units is mainly impacted by factors such as development intensity, types of housing property right, altitude, and location. In conclusion, it is suggested that urban green space layout should prioritize improving the spatial distribution and layout of residential green spaces, especially for the socially vulnerable population. Finally, the study points out that the park ratio within a 500 m service radius can be adopted as a supplement to existing greening indicators for residential areas.     

基于遥感反演的绿色空间景观格局对 气溶胶污染的影响

气溶胶对人类的生命健康具有重要影响,绿色空间 被认为是缓解气溶胶污染的重要生态设施。既往研究集中于单 个污染因子与土地利用的相关研究,但对绿色空间景观格局与 综合空气污染物空间规律的定量化研究较少。以武汉市为例, 基于遥感影像,利用ENVI、ArcGIS提取绿地和AOD数据, 运用Fragstats计算绿色空间景观指数,从统计学规律和空间 分布规律两方面研究了绿地景观格局与AOD的关系。研究发 现：1)绿色空间景观指数和AOD都具有显著的空间集聚特 征;2)绿色空间景观格局缓解气溶胶污染的核心景观指数指标 为CA、PLAND、LPI、COHESION、AI;3)基于地理加权 回归的绿色空间核心景观指数对AOD浓度分布影响具有空间 差异。提出了绿色空间核心景观指数缓解气溶胶污染的调控策 略,旨在从缓解气溶胶污染角度出发,为绿色空间类生态规划 设计等提供参考,为人居健康环境和公共卫生安全建设提供理 论依据。