Long-term stormwater quantity and quality performance of permeable pavement systems

This study examined the long-term effectiveness of permeable pavement as an alternative to traditional impervious asphalt pavement in a parking area. Four commercially available permeable pavement systems were evaluated after 6 years of daily parking usage for structural durability, ability to infiltrate precipitation, and impacts on infiltrate water quality. All four permeable pavement systems showed no major signs of wear. Virtually all rainwater infiltrated through the permeable pavements, with almost no surface runoff. The infiltrated water had significantly lower levels of copper and zinc than the direct surface runoff from the asphalt area. Motor oil was detected in 89% of samples from the asphalt runoff but not in any water sample infiltrated through the permeable pavement. Neither lead nor diesel fuel were detected in any sample. Infiltrate measured 5 years earlier displayed significantly higher concentrations of zinc and significantly lower concentrations of copper and lead.     

澳大利亚水敏性城市转型历程及其启示

澳大利亚作为西方发达国家可持续性雨洪管理领域的先驱,其提出的水敏性城市设计(WSUD)在城市建设实践中得到广泛应用,取得了良好的效果。从雨洪技术、政策、管理等方面回顾了澳大利亚雨洪管理近60年的转型历程,分析转型中遇到的困境及应对策略,并对我国海绵城市建设提出建议。     

Mitigation of urban flooding: A simplified approach for distributed stormwater management practices selection and planning

The urbanization process and the hydraulic insufficiency of drainage systems are two of the most common causes of urban flooding. In some technical regulations, distributed stormwater management practices (DSMPs) are regarded as a solution for urban flooding problems. They can prevent the formation of runoff, dispose of it locally, or dampen its peak before it reaches the drainage system. Due to their diffuse localization and the wide number of available solutions, the evaluation of their efficiency in terms of flood reduction is very difficult.

The methodology proposed in the present paper relies on the concept that the mitigation effects of DSMPs can be expressed as a function of the changes of the hydrological parameters of a catchment. Once the relation between a DSMP and the equivalent hydrological parameter is established, the efficiency of DSMPs can be evaluated using mathematical models simulating the runoff formation and propagation in urban areas and applying methodologies similar to parameter sensitivity analysis and model uncertainty propagation. Studying the effect of parameter variation on model output, it is possible to analyse quickly several different stormwater management solutions and to identify the best distribution of measures in order to achieve a defined mitigation task.

The simplified procedure has been compared with a more detailed approach obtained by fully integrate DSMPs in the drainage system hydrodynamic model. The procedure has been applied to the real case study of Mondello catchment in Palermo (Italy), and the analysis of the results allows the identification of some guidelines for the mitigation plan preparation.     

Stormwater runoff quality and quantity from asphalt, paver, and crushed stone driveways in Connecticut

This study compared the quality and quantity of stormwater runoff from replicated asphalt, permeable paver, and crushed-stone driveways. Rainfall was measured on-site and runoff was recorded using tipping buckets. Flow-weighted composite runoff samples were analyzed weekly for total suspended solids, total Kjeldahl nitrogen, nitrate-nitrogen, ammonia-nitrogen, total phosphorus (TP), zinc, lead, and copper. Infiltration rate was determined on each driveway annually. Repeated measures analysis of variance indicated that stormwater runoff was significantly different among each driveway type; the order of decreasing runoff was asphalt> paver> stone. Average infiltration rates were 0, 11.2 and 9.0 cm/h for asphalt, paver, and crushed stone driveways, respectively. Both paver and crushed stone driveways reduced stormwater runoff as compared to asphalt driveways. Runoff from paver driveways contained significantly lower concentrations of all pollutants measured than runoff from asphalt driveways. However, runoff from crushed stone driveways was similar in concentrations to runoff from asphalt driveways, except for TP concentrations, which were lower in runoff from crushed stone driveways than runoff from asphalt driveways. The mass export of measured pollutants followed the relative differences in stormwater runoff, rather than differences in concentrations.     

Nitrogen composition in urban runoff--implications for stormwater management

A study was conducted to characterise the composition of nitrogen in urban stormwater in Melbourne, Australia, during baseflows and storm events, and to compare the results with international data. Nitrogen in Melbourne stormwater was predominantly dissolved (approximately 80%), with ammonia the least-abundant form (approximately 11%). Concentrations of nitrogen species did not vary significantly between baseflow and storms, although the proportion of nitrogen in particulate form was higher during storm events (p = 0.04). Whilst the composition of nitrogen in Melbourne was broadly consistent with international data, the level of dissolved inorganic nitrogen was higher in Melbourne (mu = 48% during baseflows and 49% during storms) than in the international literature (mu = 29%). Limitations in the international dataset precluded comparison of total dissolved nitrogen. The results have implications for stormwater management. Whilst nitrogen species concentrations are variable, they are not strongly related to flow conditions, so treatment systems must be designed to cope with stochastic inflow concentrations at all times. To optimise their performance, stormwater treatments should be designed to improve dissolved nitrogen removal. Further research is needed to improve the ability of treatment systems to achieve this aim.     

Identification of subwatershed sources for chlorinated pesticides and polychlorinated biphenyls in the Ballona Creek watershed

Santa Monica Bay forms part of the western border of the greater Los Angeles region. The Ballona Creek watershed is highly urbanized and past studies indicate that Ballona Creek is the largest source for most pollutants to Santa Monica Bay. This study evaluates the contribution of subwatersheds to PCB and chlorinated pesticide loading during wet weather flow. Fifteen storm drains from these subwatersheds were sampled during three storms during the 2005-2006 winter rainy season. A series of grab samples were taken over the duration of the storms. The suspended solids were analyzed for polychlorinated biphenyls (PCBs) and chlorinated pesticides. A geographic information system (GIS) was used to calculate the runoff volume from each subwatershed to estimate pollution mass loading. There was no statistical difference among subswatersheds; however, a disproportionate mass of PCB loading came from site 5, which had no obvious sources. No specific subwatersheds were identified as key sources for chlorinated pesticides. These results may serve as a model for other locations with concerns for historic PCB and chlorinated pesticides loadings.     

Eco-friendly pervious concrete infrastructure for stormwater management and bicycle parking: a case study

ABSTRACT

A pervious concrete area (50 m²) was constructed for a dual purpose: stormwater management and bicycle parking. It consisted of two subareas (PC_a and PC_b) with dissimilar characteristics of pervious concrete mixes in strength, durability and permeability. To make the construction more eco-friendly and economical, coal fly ash was incorporated as a partial cement replacement by 21.4% in the PC_a pervious concrete mix. The PC_b was constructed with an industry proprietary pervious concrete mix. The subbase water storage can retain 4.1 m³ of the infiltrated stormwater before discharging excess water to a storm drain. The drainage water had an improved water quality in turbidity, organic carbon, phosphorus and fecal coliform concentrations. However, it had high pH and conductivity which might cause a negative impact on the environment. The constructed area has been in active use since its opening, accommodating ~30 bicycles at once on the safe and comfort pervious surface.     

德国汉诺威康斯柏格城区一期工程雨洪利用与生态设计

德国汉诺威康斯柏格城区的雨洪利用与生态设计是欧洲的典范.本文从研究雨洪滞留与八渗系统的构成与模式入手,进一步研究了"雨水滞滤沟"、"坡地雨水滞留绿道"、"场地最低洼处的雨水滞留区"三项生态化措施与"艺术景观设计"、"体验式教育"、"居民参与生态设计"三项特色措施,最后总结其设计特点,并指出在国内景观规划设计中加强雨洪利用的研究,应用生态设计的手段解决环境问题,是当代景观设计的焦点之一.以上研究为中国的雨洪利用与生态设计提供借鉴和参考.     

城市湿地的开发利用与保护对策研究——以西安市为例

城市湿地是城市生态系统重要的组成部分,是城市可持续发展依赖的重要生态基础设施。该文阐述了城市湿地的重要作用,并以西安市为例,对该地区的湿地的现状、分布以及存在的问题进行分析,探讨了开发与保护湿地的对策,以期对西安市湿地的可持续利用提供依据.     

Rainwater harvesting for domestic use: A systematic review and outlook from the utility policy and management perspectives

In recent years, water insecurity has been reported as a problem of worldwide concern. Rainwater harvesting (RWH) for some domestic uses is regarded as a path out of this situation. However, in some localities, RWH has been the sole water source for all domestic and non-domestic uses. In recent times, research in RWH has gained more traction from the operationalization and engineering perspectives. However, for direct rainwater usage to become a societal norm and generate significant societal benefits, studies in RWH must assess the alignment of outcomes from policy and management perspectives. Therefore, a comprehensive literature review of 83 collated papers on RWH is conducted in two stages. First, a systematic review of the literature is performed to identify the thematic content (structure of the literature, problem orientation), contextual application (technical and social considerations), and theoretical alignment scope (neo-institutional theory, agency theory, and ecological modernization theory). Second, gaps in the literature are identified, and theoretical alignment of the ideas from policy and management perspectives is proposed to advance RWH research. Key findings are: (1) despite RWH being aimed to provide social benefits, the present literature is constrained in supporting social policy-making and management of rainwater as a public utility system; (2) policy and governance frameworks that include socio-economic and socio-environmental pragmatism are needed to achieve RWH programs realistically; and (3) modeling of RWH systems requires considering spatial variabilities, policy evaluations, and governing theories. RWH has the potential to have a central position in water resource management worldwide.     

A method for soil environmental quality evaluation for management and planning in urban areas

Soil represents a complex medium, which makes it difficult to evaluate its quality. In the past, soil quality evaluation was biased towards agricultural production rather than for purposes related to the broad range of functions and services that it performs. Soil function and soil quality in the urban environment differ due to the different needs and roles of soil within the diversity of urban land uses. The quality of urban soil should be evaluated to support public services for good environmental quality management. Planners should also adjust their decisions towards more sustainable urban design. Simple and applicable soil quality evaluation methods accompanied by an operations toolkit that could be used by laypeople are needed.This paper discusses soil functions, soil quality indicators, pedotransfer functions, and urban soil quality. It presents an urban soil quality evaluation method for different land uses within one particular evaluation system. The calculation of three one-value measures of soil quality are introduced: index of soil quality (expresses soil quality/suitability for a particular land use), soil environmental quality index (environmental value of soil) in terms of performing the crucial ecological functions of soil, and land use change index (land use planning impact assessment on soil resources). The use of the method is described in two procedures: urban soil quality control and soil evaluation for urban planning.     

A sustainable framework for water resources management in an urban watershed: the case of Volos,Greece

The implementation of sustainable development principles in water resources management refers to an integrated management and coordination of the entirety of the actions and interventions that concern the water ecosystem, or parts of it, within a watershed. This procedure is accomplished through the development and application of an overall management plan at a hydrological basin level. This concept was followed by the water resources management plan of the city of Volos' watershed, which is presented in this paper. The main objective is the choice of the best set, among others, of hydraulic projects, which will be able to re-establish the balance in the basin's deficient water budget, satisfying at the same time future urban water demand. Decision making was carried out using a GIS tool and involved traditional water capture hydraulic projects on the one hand and sustainable water saving measures on the other. The whole procedure is being developed in an area with serious environmental problems, concerning mainly the groundwater resources. The particularity here is that the alternative solutions strongly depend on administrative agreement and consensus between relevant authorities.     

Metronatural™: Inventing and reworking urban nature in Seattle

Seattle has long been considered a city in harmony with nature, a metropolis inseparable from and infused with the dramatic and picturesque Pacific Northwest landscape. Today, the city is frequently cited as a leader in sustainable urban development and this is due in large part to its unique relationship with its natural surroundings. However, the historical record of Seattle reveals this harmonious relationship between humans and nature to be a social construction. The founders of Seattle adopted an urban development approach similar to other North American cities and implemented large-scale engineering projects to rationalise the landscape while solidifying the municipal government as the ultimate arbiter of human/nature relations. The unintended economic, environmental, and social consequences of this so-called ‘Promethean’ approach to urban nature would be debunked in the 1950s, catalyzing a wide array of approaches by the municipality and residents to restore, protect, and live with nature in more benign ways. In this article, I examine the politics of nature in Seattle to understand how changing perceptions of the urban landscape are related to different forms of expertise, governance, and citizenship. I focus specifically on activities to reorient urban water flows because they reveal the multiple tensions between humans and nature. The article adds to contemporary scholarship in landscape architecture, human geography, and environmental history on the dilemma of urban nature while highlighting the central role of technical experts, practices, and networks as well as issues of governance, citizenship, and management. Seattle's reputation as a green metropolis serves as an entry point to interpret the various relationships between humans, technology, and nature while also suggesting potential routes to realise more sustainable urban futures.     

Stormwater quality associated with a silt trap (empty and full) discharging into an urban watercourse in Scotland

The aim was to assess the influence of a full silt trap at the end of a stormwater drainage pipe on the water quality of stormwater discharged into a semi‐natural urban watercourse. For approximately eleven weeks, the water qualities of the preliminarily treated stormwater and of the receiving watercourse (Braid Burn) were studied. The mean outflow concentrations of suspended solids were 2.0 mg/l and 34.1 mg/l during dry and wet weather conditions, respectively. Suspended solids concentrations of up to 141.6 mg/l were recorded during storm events. Suspended solids values for treated stormwater were often too high compared to international secondary wastewater treatment standards of around 30 mg/l. Pollutants including heavy metals (e.g., zinc, copper and nickel) accumulated in the silt trap. However, high outflow velocities during heavy rainfall events did not result in clearly defined sediment layers due to sediment re‐suspension. Metals did not accumulate in the receiving watercourse.     

Regulating sanitation services in sub-saharan africa: An overview of the regulation of emptying and transport of faecal sludge in 20 cities and its implementation

Onsite sanitation is widely used in Sub-Saharan African (SSA) cities. Safe transportation and emptying of the resulting faecal sludge are essential for healthy cities. Typically provided by an informal and unmonitored private sector, these services are being increasingly regulated. This research provides an overview of the regulatory mechanisms in place in 20 cities across SSA, their implementation and emerging common trends. Findings highlight the diversity of tools, mechanisms, and capabilities. We conclude that incremental and pragmatic change is needed to achieve fully regulated services, with adequate implementation particularly facilitated by support and incentive mechanisms, and participation of all stakeholders.     

Advancing assessment and design of stormwater monitoring programs using a self-organizing map: characterization of trace metal concentration profiles in stormwater runoff

Stormwater runoff poses a great challenge to the scientific assessment of the effects of diffuse pollution sources on receiving waters. In this study, a self-organizing map (SOM), a research tool for analyzing specific patterns in a large array of data, was applied to the monitoring data obtained from a stormwater monitoring survey to acquire new insights into stream water quality profiles under different rainfall conditions. The components of the input data vectors used by the SOM included concentrations of 10 metal elements, river discharge, and rainfall amount which were collected at the inlet and endpoint of an urban segment of the Yeongsan River, Korea. From the study, it was found that the SOM displayed significant variability in trace metal concentrations for different monitoring sites and rainfall events, with a greater impact of stormwater runoff on stream water quality at the upstream site than at the downstream site, except under low rainfall conditions (≤4 mm). In addition, the SOM clearly determined the water quality characteristics for “non-storm” and “storm” data, where the parameters nickel and arsenic and the parameters chromium, cadmium, and lead played an important role in reflecting the spatial and temporal water quality, respectively. When the SOM was used to examine the efficacy of stormwater quality monitoring programs, between 34 and 64% of the sample size in the current data set was shown to be sufficient for estimating the stormwater pollutant loads. The observed errors were small, generally being below 10, 6, and 20% for load estimation, map resolution, and clustering accuracy, respectively. Thus, the method recommended may be used to minimize monitoring costs if both the efficiency and accuracy are further determined by examining a large existing data set.     

Mass balance for polycyclic aromatic hydrocarbons in the urban watershed of Le Havre (France): transport and fate of PAHs from the atmosphere to the outlet

Polycyclic aromatic hydrocarbon (PAH) concentrations have been monitored simultaneously in ambient air, bulk atmospheric deposition and runoff waters during one year in a small urban watershed of the Seine river basin (France). PAH fluxes from the atmosphere to the outlet of the urban watershed have been calculated to establish a mass balance for PAHs. PAH flux in runoff waters was 5.2 kg km(-2) yr(-1) while PAH atmospheric deposition was 0.21 kg km(-2) yr(-1). The comparison between atmospheric input and output by runoff has shown the importance of street deposits that appeared to be the most important source of PAHs for surface waters in urban areas. PAH profiles in the various compartments showed the fate of PAHs in the air-water system: proportion of carcinogenic PAHs was more important in runoff waters (35%) than in bulk atmospheric deposition (22%) and air (6%).     

Social preferences and economic valuation for water quality and river restoration: the Segura River,Spain

The Water Framework Directive (WFD) aims at improving the ecological status of the water bodies in Europe. In this context, some rivers are currently being restored and, in accordance with this Directive, the restoration actions have to be evaluated from a socio‐economic approach. This work applies the Choice Modelling method to the WFD provisions for river restoration. This method proves to be useful for the economic valuation of the restoration measures, as well as a very important tool for people's public participation. In this sense, the water quality improvement has been defined as a priority action from a social point of view. Moreover, the method used has provided answers to both basic questions included in the WFD: the calculation of the economic value of the Segura River's ecological flow, the decrease of which would pose an environmental cost, and the estimation of the environmental income generated by this river.     

Monitoring airborne particles as mass and number concentrations: implications for air quality management and health

Airborne particulate matter is unique in that it does not have a standard or constant chemical formula or physical structure. This makes classification and measurement problematic. Many different measurement techniques have been devised to quantify airborne particles but few are comparable and it is proving very difficult to measure particles accurately in a way that reflects their potential harm to human health. Such measurements are a pre‐requisite for effective air quality management. This paper reviews the main methods used to quantify airborne particulates in the ambient urban atmosphere. Its aim is to demonstrate the importance of the measurement methods to our interpretation of health risk. Through the use of a case study the paper illustrates how, by using two different types of measurement, very different patterns of health risk are implied.     

An optimization model for water quantity and quality integrated management of an urban lake in a water deficient city

This paper presents an optimization model for water quantity and quality integrated management of an urban lake in a water deficient city. A representative water quantity and quality safeguard system served urban lake, including multi-source water supply facilities, recirculating water purification facilities and surplus water discharge facilities, is widely used in Chinese water deficient cities. Because it is complicated, any mismanagement will result in water quality deterioration, water waste and high operation cost. The presented model attempts to achieve the objectives of controlling water pollution, reducing economic cost and improving water utilization efficiency through an optimized operating water safeguard system. The model is applied to Qingjing Lake in Tianjin, China. Results show that the model plays a more positive role for water quantity and quality integrated management.