国外雨水管理理念与实践

近年来,城市暴雨内涝问题得到各界广泛关注,城市雨水管理的重要性日益凸显。本文研究了国外雨水管理的发展历程,概述了"最佳管理实践"、"低冲击开发"、"水敏城市设计"和"可持续性城市排水系统"等国际主流城市雨洪管理策略,同时对近年来世界先进城市防治内涝方面的管理措施进行了归纳总结;最后,在思想意识、排放体制、措施等方面与中国目前排水体制进行了对比,并归纳了三种理念的适用范围,希望根据国内实际条件的不同,因地制宜地制定适合中国特色的雨水管理理念。     

Seasonal first flush phenomenon of urban stormwater discharges

California's climate, typified by winter and spring precipitation and summer drought, is often called a Mediterranean climate, and creates a long period for pollutant build-up. The initial storms of the winter season usually have higher pollutant concentrations, which is called a seasonal first flush. To investigate the existence of a seasonal first flush, we analyzed four major data sets, collected over the 1999-2000 to 2002-2003 wet seasons. Trends in seasonal loads were quantified by plotting pollutant concentrations or cumulative pollutant load versus cumulative rainfall or cumulative runoff volume. Pollutant concentrations in the first part of the wet season were ranged from 1.2 to 20 times higher than concentrations near the end of the season, and mass emission rates were similarly higher at the beginning of the season. A seasonal first flush existed for most cases and was strongest for organics, minerals and heavy metals except lead. This result suggests that applying treatment Best Management Practices (BMPs) early in the season could remove several times more pollutant mass than randomly timed or uniformly applied BMPs.     

城市暴雨处理及分析集成模型系统(SUSTAIN)介绍

暴雨的管理与控制已经成为制约城市可持续发展的重要议题之一,最佳管理实践(BMP)和低影响开发(LID)策略的提出,对于改变传统观念、建立新型的城市暴雨管理体系具有积极意义,但缺乏有效的设计与评估工具,制约了该理念的工程推广与应用。美国国家环保局(USEPA)支持开发的城市暴雨处理及分析集成模型系统(SUSTAIN),以ArcGIS为基础平台,综合应用了水文、水力和水质分析模型,可以对BMP和LID的措施类型、安置地点和实施效果进行科学有效的设计与评估,对于在我国开展暴雨管理措施的模型分析与设计评估具有很好的借鉴意义。     

A study on pesticide runoff from paddy fields to a river in rural region--2: development and application of a mathematical model

A mathematical model was developed to predict the runoff of pesticides from paddy fields to a river in a rural region. The model comprises three submodels: (1) submodel for river flow, (2) submodel for pesticide behavior in paddy fields, (3) submodel for pesticide behavior in a river. The tank model was applied to predict the river flow and the paddy water. In order to reproduce the actual behavior of pesticides in paddy fields, the kinetics of the transport and reaction mechanisms of pesticides applied to paddy fields were considered in the model. The model was applied to the Kozakura River Basin where the detailed field survey was conducted. The model reflected well the runoff characteristics of pesticides obtained from the detailed field survey.     

Using SWAT, Bacteroidales microbial source tracking markers,and fecal indicator bacteria to predict waterborne pathogen occurrence in an agricultural watershed

Developing the capability to predict pathogens in surface water is important for reducing the risk that such organisms pose to human health. In this study, three primary data source scenarios (measured stream flow and water quality, modelled stream flow and water quality, and host-associated Bacteroidales) are investigated within a Classification and Regression Tree Analysis (CART) framework for classifying pathogen (Escherichia coli 0157:H7, Salmonella, Campylobacter, Cryptosporidium, and Giardia) presence and absence (P/A) for a 178 km² agricultural watershed. To provide modelled data, a Soil Water Assessment Tool (SWAT) model was developed to predict stream flow, total suspended solids (TSS), total N and total P, and fecal indicator bacteria loads; however, the model was only successful for flow and total N and total P simulations, and did not accurately simulate TSS and indicator bacteria transport. Also, the SWAT model was not sensitive to an observed reduction in the cattle population within the watershed that may have resulted in significant reduction in E. coli concentrations and Salmonella detections. Results show that when combined with air temperature and precipitation, SWAT modelled stream flow and total P concentrations were useful for classifying pathogen P/A using CART methodology. From a suite of host-associated Bacteroidales markers used as independent variables in CART analysis, the ruminant marker was found to be the best initial classifier of pathogen P/A. Of the measured sources of independent variables, air temperature, precipitation, stream flow, and total P were found to be the most important variables for classifying pathogen P/A. Results indicate a close relationship between cattle pollution and pathogen occurrence in this watershed, and an especially strong link between the cattle population and Salmonella detections.     

Modeling and physical interpretation of photocatalytic oxidation efficiency in indoor air applications

Volatile organic compounds (VOCs) are the major pollutants in indoor air, which significantly impact indoor air quality (IAQ). As a promising technique to remove VOCs, photocatalytic oxidation (PCO) takes the advantages of oxidation of a large range of VOCs with low energy consumption. In this study, the mass transports and reaction mechanism involved in the PCO process have been studied. In addition, the kinetic models of PCO on the different conditions of elementary reactions have been critically reviewed. Moreover, the factors that may affect the efficiency of PCO were interpreted based on the established fundamental mechanism of PCO. Some recommendations were made for future work to improve the efficiency of PCO system for building applications.     

Modeling the behaviors of adsorption and biodegradation in biological activated carbon filters

This investigation developed a non-steady-state numerical model to differentiate the adsorption and biodegradation quantities of a biological activated carbon (BAC) column. The mechanisms considered in this model are adsorption, biodegradation, convection and diffusion. Simulations were performed to evaluate the effects of the major parameters, the packing media size and the superficial velocity, on the adsorption and biodegradation performances for the removal of dissolved organic carbon based on dimensionless analysis. The model predictions are in agreement with the experimental data by adjusting the liquid-film mass transfer coefficient (k(bf)), which has high correlation with the Stanton number. The Freundlich isotherm constant (N(F)), together with the maximum specific substrate utilization rate (k(f)) and the diffusion coefficient (D(f)), is the most sensitive variable affecting the performance of the BAC. Decreasing the particle size results in more substrate diffusing across the biofilm, and increases the ratio of adsorption rather than biodegradation.     

Modeling spatially explicit population dynamics of Pterostichus melanarius I11. (Coleoptera: Carabidae) in response to changes in the composition and configuration of agricultural landscapes

The intensification of agricultural practices has induced the local, national and regional extinction of many species and also affected ecosystem services provided by biodiversity such as biological control of agricultural pests. We model the population dynamics of Pterostichus melanarius (Coleoptera: Carabidae), a carabid beetle often used as indicator species of habitat changes, by a joint model that combined a matrix model of population dynamics including local dispersal with an explicit model of the patchy landscape of the polders of the Bay of Mont St. Michel (Brittany, France). We used this model to evaluate the effects of landscape composition and configuration on the spatial population dynamics of this carabid beetle, and also investigated the consequences that different management strategies of the structure and composition of an agricultural landscape can have on its abundance and spatial distribution. The results of this study highlight that semi-habitats (field edges, dykes, hedgerows) usually considered as shelters for wintering play a key role as well for summer recruitment. We find that there is an optimal cluster size of patches for population viability that is induced by the seasonal movement of P. melanarius. However, the effect of increasing the amount of semi-natural habitats patches on the viability of this population critically depend on the spatial arrangement, connectivity and spatial alternation of the network of semi-natural habitats, a feature that should be considered in the conservation and management actions in the landscape context.     

Effects of Mg and H on the toxicity of Ni to the unicellular green alga Pseudokirchneriella subcapitata: Model development and validation with surface waters

In this study, increasing Mg concentrations and decreasing pH were observed to decrease Ni toxicity to the green alga Pseudokirchneriella subcapitata. To investigate to what extent the original biotic ligand model (BLM) concept could explain Ni toxicity as a function of water chemistry, the protective effects of Mg²⁺ and H⁺ were modeled as BLM-type single-site competition effects. The model parameters representing these effects were log K_MgBL = 3.3 and log K_HBL = 6.5. The BLM was capable of predicting Ni toxicity by an error of less than a factor of 2 in most synthetic and natural waters used in this study. However, since the relationship between 72-h E_rC50_Ni²⁺ (i.e. the 72-h E_rC50 expressed as Ni²⁺ activity) and H⁺ activity was not linear over the entire tested pH range, only the ‘linear part’ between pH 6.45 and 7.92 was used for derivation of log K_HBL. This nonlinearity indicates that the effect of pH can probably not be attributed to H⁺ competition with Ni²⁺ for a single site alone. When modeling the effect of pH as a linear relation between 72-h E_rC50_pNi²⁺? (= − log (72-h E_rC50_Ni²⁺ corrected for the presence of Mg)) and pH, the applicability of the model was successfully extended to pH levels as low as 6.01. This type of empirical model has also been used in our previous studies on the development of a chronic Ni bioavailability model for Daphnia magna and a long-term Ni bioavailability model for rainbow trout. Finally, we could not detect a statistically significant interactive effect of pH and Mg on the toxicity of Ni²⁺ to P. subcapitata and this is in line with the formulation of our empirical model.     

建筑遗产全生命周期管理与建筑信息模型研究——以柬埔寨茶胶寺南外门为例

建筑信息模型技术使建筑的非几何属性与实体图元产生一致性关联,具有设计参数化、数据可视化、统计自动化、工作协同化等特点。经过系统的专业化开发,建筑信息模型（BIM）技术能够解决目前建筑遗产信息管理中的＂信息孤岛＂问题,它与地理信息系统（GIS）技术结合,可搭建起建筑遗产的全生命周期管理平台。以柬埔寨茶胶寺南外门为典型个例,重点研究了BIM软件专业化开发中石头建筑的族库分类、构件属性设置以及模型阶段化设计的问题,逐步探索大规模专业族库开发的理论和方法。     

Identifying the sources and fate of anthropogenically impacted dissolved organic matter (DOM) in urbanized rivers

Anthropogenic activities have dramatically changed the loads and compositions of dissolved organic matter (DOM) in urbanized streams. In this study, the spatial and temporal variations of DOM in the anthropogenically impacted Zhujiang River were investigated by analyzing the water samples in an upstream, urbanized area and downstream of the rivers on different days of one year. The results indicated that the levels of dissolved organic carbon (DOC) and total phosphorus (TP) were unaffected by seasonal changes, but the specific UV₂₅₄ absorbance (SUVA) values and the total nitrogen (TN) content were greater in the winter than those in the summer. Parallel factor (PARAFAC) analysis of the excitation emission matrices (EEM) revealed the presence of three anthropogenically derived components [tryptophan-like (C1) and tyrosine-like proteins (C3) and anthropogenic humic substances (C5)] in the urbanized rivers, and they had greater seasonal and spatial variability than the terrestrial and microbial humic substances (C2 and C4). Cluster analysis revealed that treated wastewater was an important source of DOM in the urbanized streams. Photodegradation experiments indicated that the DOM in the populous area of the rivers had greater photodegradation potentials than that in the downstream region or in the natural waters. Interestingly, that the anthropogenic humic substances (C5) were considerably more photoreactive than the other four PARAFAC components, which exhibited a decrease of 80% after exposure to sunlight for 0.5 d. This study suggests that the treated wastewater could be an important input to the DOM in the urbanized rivers and the naturally occurring photodegradation could help in eliminating the anthropogenic DOM during their transport.     

Quantification of stormwater runoff using a combined GIS and curve number approach: a case study for an urban watershed in the Ozark Highlands,USA

Managing stormwater runoff is crucial to preserving water quality in rapidly developing urban watersheds. The objective of this study was to develop a methodology to test existing stormwater drainage infrastructure, identify potential areas of improvement, and estimate potentially contaminated runoff by combining two widely used stormwater runoff prediction models. A watershed containing much of the University of Arkansas-Fayetteville campus was targeted for this study because stormwater from this watershed drains into a local river designated as an impaired water body due to siltation. The curve number method was used to estimate runoff for various flood-return periods and antecedent moisture conditions, while a flow-direction model integrated topography, land use, and stormwater drainage infrastructure in a GIS. The methodology developed and results generated will help stormwater planners visualise localised runoff and potentially adapt existing drainage networks to accommodate runoff, prevent flooding and erosion, and improve the stormwater quality entering nearby surfacewater bodies.     

澳大利亚水敏城市设计(WSUD)演进及 对海绵城市建设的启示

海绵城市建设需要多层面、全方位综合推进,针对目前中国海绵城市建设中面临的问题,通过解析澳大利亚城市水管理目标的转型及水敏城市设计(WSUD)演进过程,将水敏城市设计演进分为萌芽、产生、示范及应用4个阶段,进而分析其演进中的成功经验与前沿趋势,为我国当前海绵城市建设与低影响开发景观规划设计以启示与借鉴。认为我国海绵城市建设需要从行政与制度建设、设计科学依据、项目监测与评价、项目示范推广,以及处置序列合理组织5个方面进行改进与突破,从而真正实现海绵城市的建设目标。     

Source apportionment of human personal exposure to volatile organic compounds in homes, offices and outdoors by chemical mass balance and genetic algorithm receptor models

A number of past studies have shown the prevalence of a considerable amount of volatile organic compounds (VOCs) in workplace, home and outdoor microenvironments. The quantification of an individual's personal exposure to VOCs in each of these microenvironments is an essential task to recognize the health risks. In this paper, such a study of source apportionment of the human exposure to VOCs in homes, offices, and outdoors has been presented. Air samples, analysed for 25 organic compounds and sampled during one week in homes, offices, outdoors and close to persons, at seven locations in the city of Leipzig, have been utilized to recognize the concentration pattern of VOCs using the chemical mass balance (CMB) receptor model. In result, the largest contribution of VOCs to the personal exposure is from homes in the range of 42 to 73%, followed by outdoors, 18 to 34%, and the offices, 2 to 38% with the corresponding concentration ranges of 35 to 80 microg m(- 3), 10 to 45 microg m(- 3) and 1 to 30 microg m(- 3) respectively. The species such as benzene, dodecane, decane, methyl-cyclopentane, triethyltoluene and trichloroethylene dominate outdoors; methyl-cyclohexane, triethyltoluene, nonane, octane, tetraethyltoluene, undecane are highest in the offices; while, from the terpenoid group like 3-carane, limonene, a-pinene, b-pinene and the aromatics toluene and styrene most influence the homes. A genetic algorithm (GA) model has also been applied to carry out the source apportionment. Its results are comparable with that of CMB.     

Onset of severe nitrification in mildly nitrifying chloraminated bulk waters and its relation to biostability

Triggers of severe nitrification in distribution systems are still not clearly understood. Recently, the biostability concept was proposed to explain the chloramine residual below which signs of nitrification would be seen. To improve understanding, mildly nitrifying bulk water samples (nitrite less than 0.010mg-N/L) from Sydney Water distribution systems were incubated at constant temperatures and periodically analysed for nitrogenous compounds and total chlorine. Total ammoniacal nitrogen in the sample was between 0.25 and 0.35mg-N/L. Severe nitrification was triggered when chloramine residuals dropped below about 0.4mg/L - the critical threshold residual. In 45 such samples, the critical threshold residual was 0.2-0.65mg/L. The biostability concept was found to be useful in explaining the residual below which net growth of microorganisms begins. However, this alone could not predict the critical threshold residual. Different means of overcoming this problem are discussed. One of these is the use of the microbial decay factor method, since microbiologically assisted chloramine decay in the samples studied was found to be mostly the result of ammonia-oxidising bacterial activity. Nitrite levels in winter were found to be poor indicators of nitrifying status. Overall the results were found to be useful in controlling nitrification and to obtain early warning of severe nitrification.     

A Study of Human Reactions to Emissions from Building Materials in Climate Chambers. Part II: VOC Measurements,Mouse Bioassay,and Decipol Evaluation in the 1–2 mg/m3 TVOC Range

Monitoring of human reactions to the emission of formaldehyde and volatile organic compounds (VOC) from four commonly used building materials was carried out. The building materials were: a painted gypsum board, a rubber floor, a nylon carpet, and a particle board with an acid-curing paint. The exposures were performed in climate chambers. The air quality was quantified on the decipol scale by a trained panel, measurements of formaldehyde and VOC being performed simultaneously. The irritating potency of the materials was measured by a mouse bioassay. The VOC measurements showed several malodorants and irritants. Some abundant VOC identified in the head-space analyses were absent in the climate chamber air. The rubber floor and the nylon carpet exhibited a marked increase in decipols compatible with a number of odorous VOC identified in the air. A high formaldehyde concentration (minimum 743μg/m³) was measured for the particle board coated with an acid-curing paint. This was not reflected by a corresponding relatively high decipol value but a long-lasting irritating potency was observed in the mouse bioassay. TVOC sampled on Tenax and expressed in mass per volume as well as in molar concentration, and decipol evaluation both have limitations and should be used with caution as indicators of (perceived) indoor air quality. Eye irritation expressed by means of the eye index reflecting the tear film quality index (comprised of break-up time, foam formation, thickness of the precorneal lipid layer of the tear film, and epithelial damage) was found to be insensitive to formaldehyde and a VOC mixture but sensitive to TVOC concentrations of 1–2 mg/m³. Lipophilic VOC may be the cause of reduced tear film quality by destabilization of the lipid multilayer of the tear film.     

Financial and energy impacts of compact fluorescent light bulbs in a rural setting

Within the context of a national campaign to replace GLS with CFLs, a pilot study was undertaken in Niha, Lebanon to replace around 1000 light bulbs. This paper reports on the detailed savings actually obtained by this project. Energy savings were found to be 8.3%. The obtained savings were lower than the theoretical savings expected mainly due to apparent lower time of use than expected prompting a more moderate advertised yearly savings. The beneficiaries’ attitude towards CFLs was assessed and the results indicate a general satisfaction and willingness to purchase CFLs. One major drawback has been the dissatisfaction with light intensity. The impact of the campaign on other village residents was assessed and the campaign was successful in convincing one third of the population to install CFLs and two thirds said that they intend to buy CFLs in the future. A new approach in the campaign for CFL promotion is suggested.