Integrated Lake and Catchment Phosphorus Model– A Eutrophication Management Tool. I: Model Theory

The paper describes an integrated lake and catchment model which was developed and tested against data from the Rutland Water catchment (River Nene and Welland) in Eastern England. The model uses export coefficients to predict annual diffuse losses of phosphorus from catchment land use, which are temporally disaggregated using empirical relationships between phosphorus load and discharge in headwater streams. Dynamic inputs of phosphorus are incorporated into a hydrologically based, multi-reach distributed catchment model which also simulates sewage discharges, abstractions and reservoirs/ lakes. The model allows a comparison of simulated output with observed discharge and water-quality data from various points within the river system.     

Integrated Lake and Catchment Phosphorus Model -A Eutrophication Management Tool. II: Application to Rutland Water

An integrated lake and catchment model was used to simulate reservoir volume and phosphorus concentrations in Rutland Water over a period of seventeen years, taking into account changes in reservoir output and phosphorus sedimentation resulting from the addition of ferric sulphate. Application of the model for critical-period analysis and the setting of environmental targets and trigger values are discussed, and an example is given showing the impact of changing reservoir output on the frequency distribution of phosphorus using an eighty-year set of river-discharge data. The impact of phosphorus removal at point sources in the catchment on phosphorus concentrations in the river and reservoir is simulated and compared to results from SIMCAT - a steady-state model which was developed by the Environment Agency. Results are also compared with observed data following the implementation of the EC urban waste water treatment Directive, at the end of 1998.     

Eutrophication problems in Emilia Romagna,Italy: Monitoring the nutrient load discharged to the littoral zone of the Adriatic Sea

The deteriorating eutrophic state of the northern Adriatic Sea led to the commissioning of a study between 1977 and 1979 to identify the sources and forms of the nutrients phosphorus and nitrogen discharged from the basin of the river Savio. The study investigated the reduction in the phosphorus load in sewage per head of population caused by a reduction in the phosphorus content of detergents used in the basin and by the use of septic tanks. The flow and nutrient loads carried by the river were monitored during dry and wet weather to establish annual nutrient loads carried to the sea. An extensive sampling programme was carried out to quantify the principal sources of nutrients of which the most important were pig farming, Man and chemical fertilisers. An attempt was made to balance the nutrient loads discharged from the basin.     

Derivation of an 88-Year Inflow Record for Talla Reservoir, Scotland, with Special Reference to Low Flows

A new synthetic inflow record for Talla Reservoir is derived from reservoir log data for the period 1907–94. The paper describes (i) the procedures which were adopted for the derivation, based upon a reservoir water balance, and (ii) the changes in contributing area. For the years since construction of an upstream reservoir in 1968, the summer analysis draws on data from a neighbouring catchment in order to provide analysis of a more homogeneous time series. The paper also discusses the possibility of undertaking similar work for other reservoirs, as a means of improving the knowledge of the past variability of UK water resources.     

Algal growth in warm temperate reservoirs: kinetic examination of nitrogen, temperature, light, and other nutrients

Nutrient limited growth of the phytoplankton assemblage in two Texas reservoirs was studied by a combination of nutrient addition experiments and statistical modeling. Dilution bioassays were run to ascertain the qualitative and quantitative patterns in nutrient limitation. Algal growth was frequently and strongly nutrient limited, particularly when temperature was >22°C. By itself, N was more often stimulatory than P, though strong additional enhancement of growth by P and trace nutrients was often detected. Monod growth kinetics indicated that half-saturation constants for N limited growth for the entire algal assemblage were in the range 20–200 μg N/L, relatively high compared to literature values, and increased with increasing temperature. Maximal growth was also an increasing function of temperature. A single temperature-dependent model was fit to the growth dynamics for all experiments showing N-limitation. The model μ=0.0256·T([DIN]/66.0+[DIN]) where μ is specific growth rate (d⁻¹), T is temperature (°C) and [DIN] is dissolved inorganic N (μmol/L) fit the experimental results reasonably well (r²=0.82). However, only a modest predictive power for growth in the controls (our best estimate of growth in situ) was achieved (r²=0.26). Thus, even with unusually detailed, site-specific fitting of model parameters, accurately modeling algal growth in natural ecosystems can remain a challenge.     

Land-Treatment Systems: Design and Performance with Special Reference to Reed Beds

The principles of design of a land treatment system are explained on the basis of determining the land area requirements of particular constituents in terms of the supply rate and assimilative capacity. Illustrative data are provided for the design and performance of slow-rate and overland flow systems.
The paper includes a comprehensive report on the design and performance of pilot studies carried out on a reed-bed treatment system at Valleyfield, Fife, Scotland. This provides valuable insight into the choice of the bed substrate and the problems of reed establishment. Of the media tested, coarse pulverized fuel ash appeared to be promising in terms of its hydraulic conductivity and reduction in biochemical oxygen demand. For a domestic sewage of typical strength, a bed area of 5 m² per population equivalent yielded an effluent having a BOD of less than 20 mg/1, but did not provide conditions which were conducive to significant nitrogen removal.     

A preliminary modeling analysis of water quality in Lake Okeechobee, Florida: Diagnostic and sensitivity analyses

A deterministic mass balance model for nutrient and phytoplankton dynamics was previously developed and calibrated to a comprehensive set of field data for Lake Okeechobee. In the present study, diagnostic and sensitivity analyses were conducted with the calibrated model to better understand factors controlling phytoplankton and load-response dynamics in the lake. Phytoplankton growth rate limitation due to underwater light attenuation appears to be substantially greater than growth rate limitation due to non-optimal phosphorus concentrations. Phytoplankton biomass appears strongly controlled by the supply rate of dissolved available phosphorus to the water column. The dynamics of total phosphorus and chlorophyll a concentrations in the lake are strongly influenced by sediment-water phosphorus fluxes. There is a wide range of uncertainty in responses of total phosphorus and cholorophyll a concentrations to changes in tributary phosphorus loadings. Much of this uncertainty is due to a lack of quantitative understanding of sediment responses to changes in tributary loadings. Other important factors are inter-annual variability in hydrometeorological conditions and the potential influence of wind-induced resuspension of particulate phosphorus. Responses of total phosphorus and chlorophyll a concentrations for a given change in tributary loading depend not only on the magnitide of the loading change, but also on the time frame after the loading change due to a lag in sediment response. Load-response predictions for Lake Okeechobee must take into account changes in available phosphorus loadings to the water column, and must be premised on assumptions for changes in internal phosphorus loadings from the sediments. Results from this preliminary modeling analysis are provisional in that they do not include potential nitrogen limitation, potential interactions between phosphorus and nitrogen, or phytoplankton responses to potential nitrogen fixation.     

An Assessment of the Potential of the TWINSPAN Program of Multi-variate Analysis to Contribute to the Classification and Management of Village Landscapes, with Reference to Historical Features

The potential of Village Design Statements and other initiatives to achieve their stated objectives without a comparison between several villages is questioned. The basic premise is, therefore, that local decision making should be informed by analyses which show which features are common and which are confined to particular areas. The TWINSPAN (two-way in dicator species analysis) program is used to identify a number of village types within part of north-west England and these classes are shown to have historical and environmental meaning. It is, however, recognized that such analyses do not assign value, that such a step remains for the local community or the professional.     

An Assessment of the Potential of the TWINSPAN Program of Multi-variate Analysis to Contribute to the Classification and Management of Village Landscapes,with Reference to Historical Features

The potential of Village Design Statements and other initiatives to achieve their stated objectives without a comparison between several villages is questioned. The basic premise is, therefore, that local decision making should be informed by analyses which show which features are common and which are confined to particular areas. The TWINSPAN (two-way in dicator species analysis) program is used to identify a number of village types within part of north-west England and these classes are shown to have historical and environmental meaning. It is, however, recognized that such analyses do not assign value, that such a step remains for the local community or the professional.     

Responses of Cyperus involucratus Rottb. to nitrogen and phosphorus, with reference to wastewater reclamation

There is increasing use of aquatic plants in biosystems to ameliorate wastewaters. Cyperus involucratus Rottb. is a large emergent aquatic plant which may be useful in treating wastewater because it grows quickly, does not die back in winter, has little weed potential and grows in dryland situations. Many wastewaters contain high levels of N and P, and the capacity of C. involucratus to take up these nutrients was studied under glasshouse conditions. Maximum growth was attained between 84 and 168 mg NO₃-Nl⁻¹ and 1–5 mg PO₄-Pl⁻¹. At a low level of supplied NO₃-N, most of the N in plant organs was reduced-N; at levels of supplied NO₃-N above 84 mg l⁻¹, there was considerable accumulation of NO₃-N in plant organs. The accumulation of NO₃-N was greatest in culms where it made up over 50% of their N content when plants were grown on 350 mg NO₃-Nl⁻¹. Linear regression equations best described the relationships between dry matter and reduced-N contents in roots, culms and leaves. Over 60% of the total plant N and P accumulated in above ground organs, and concentrations of up to 0.53% P and 3.4% N (dry wt basis) were recorded in leaves. C. involucratus would be a suitable plant for wastewater reclamation on account of its high dry matter production, its ability to tolerate hyper-eutrophic levels of N and P, and the accumulation of most of the N and P in the harvestable portions of the plant.     

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.     

历史城市眺望景观保护管理体系研究——以英国伦敦为例

英国伦敦的眺望景观保护与管理具有悠久的历史、完整的体系和较强的可操作性,是历史城市眺望景观保护管理的典型案例。从历史城市保护的角度对英国伦敦眺望景观保护管理体系进行分析,梳理其萌芽、发展与成熟3个历史阶段;分析城市区域、历史城区和单体建筑的层级构成;并在之前学者研究的基础上着重阐释单体建筑为主体的精细化保护和城市区域为主体的框架性管理的技术要点。进一步揭示英国经验对中国历史城市眺望景观的保护管理工作的启示。     

数字化城市管理的成效、问题与对策——基于江苏四市(区)的调研

数字化城市管理模式在江苏推进以来,在提高城市问题发现能力、问题处置效率、综合管理水平等方面取得了明显成效。同时,在体制机制、推进主体、队伍建设、参与主体等方面也存在亟待解决的问题。文章认为,深入推进数字化城市管理应把握好数字城管与"大城管"、数字城管与数字政府、数字城管与城市综合执法的关系,进一步理顺体制机制,合理定位监督中心和指挥中心;全面调动社会力量,共同参与城市治理;加强绩效考核,着力提高问题处置率;拓展应用范围,逐步向数字城市过渡。     

历史街区业态发展的度量方法与评估初探--基于大栅栏、南锣鼓巷、三坊七巷的试验与比较分析

业态发展的合理引导是历史街区普遍面临的重要问题,但在度量分析方法的构建中如何有效的印证主观认知并能平衡定量分析精度、实践调查工作量及适应多样化和动态变化的街区是一个重要的问题。本文从业态线密度的思路出发,利用GIS缓冲区工具转换形成一套业态缓冲区、业态界面比的概念和度量方式,并构建了一套业态类型和品质分类办法,选取大栅栏、南锣鼓巷、三坊七巷三个历史街区作为研究对象,对商居关系、业态类型结构和品质结构进行定量分析,再结合空间分布与人群结构的观察形成综合比较评估,从中得出一些思路和方法以期为相关地区的发展和研究提供借鉴。     

公共体育场馆的建设标准刍议

公共体育场馆的建设面临多重复杂的问题，快速发展的局面、广泛的歧异性理解以及现行有限而单一的体育场馆标准正在影响体育建筑的科学发展。本文试图梳理问题，为后续研究奠定基础。     

Digital Ethnography as Planning Praxis: An Experiment with Film as Social Research,Community Engagement and Policy Dialogue

Stories and storytelling are part of a post-positivist paradigm of inquiry influenced by phenomenology, ethnography and narrative analysis, along with the evolution of visual methods in social research. New information and communication technologies today provide the opportunity to explore storytelling through multimedia, including video/filmmaking, in what we describe as digital ethnography. While there has been a tradition in the planning field of using film for advocacy purposes since the 1920s, we argue for a new direction informed by collaborative planning theory and situational ethics.

This paper reports on a three-year, three-stage research project in which we experimented with the use of film as a mode of inquiry, a form of meaning making, a way of knowing, and a means of provoking public dialogue around planning and policy issues (in this case, community development and the social integration of immigrants). We explored the expressive as well as analytical possibilities of film in conducting social research and provoking community engagement and dialogue, taking advantage of the aesthetic and involving dimensions of film as narrative. The research question was a socio-political one: how do immigrants become integrated into a specific social fabric, and how do they acquire a sense of belonging? The site of the research was a culturally diverse neighbourhood in the city of Vancouver, and the specific focus was a place-based local institution, the Collingwood Neighbourhood House. The paper concludes with critical reflections on the use of film in this research project, focusing on ethical issues, power relationships, insider/outsider dilemmas, and reciprocity.     

预警、响应与恢复 — —韧性城市视角下应对突发公共卫生事件的规划策略研究

新型冠状病毒肺炎疫情（COVID-19） 的爆发严重影响了人们的生命健康和日常生 活,城市中的人口与生产生活资源等相对集 中,突发公共卫生事件发生时往往损失更 严重。韧性城市能够有效应对突发性灾害风 险,通过一系列干预措施帮助城市从崩溃状 态过渡到自组织循环稳态,并逐渐恢复。在 此背景之下,本文首先梳理了韧性城市的概 念与特征,通过分析韧性城市特征与突发公 共卫生事件应对措施之间的响应关系,探讨 了韧性城市规划应对突发公共卫生事件的适 用性。然后,基于韧性城市规划框架中的脆 弱性分析、城市管治、预防和不确定性导向规划四个方面,结合突发公共卫生事件发展周期,构建了预警、响应和恢复框架。最后,基于框 架提出了应对策略：预警层面,对潜在风险进行评估并构建早期预警系统,做好防灾准备;响应 层面,提出城市应急资源的冗余配置、城市基础设施的多元建设、城市生态环境的多层协作和社 区层级的自组织响应四大规划策略;恢复层面,注重韧性城市规划的重建与修复,强调灾后评 估与反馈,同时提升公众防灾意识。     

理性精神与同济实践米兰三年展之“从研究到设计——同济建筑师展”

有着悠久历史的米兰三年展对世界范围认识设计和建筑具有举足轻重的影响力。2012年米兰三年展“从研究到设计——同济建筑师展”,邀请包括2012年普利兹克建筑奖得主王澍在内的27位建筑师及其团队的50个建成作品参展,从不同视角描绘了当代中国建筑的真实相貌。因为参展建筑师全都毕业于同济大学建筑系或者在同济大学任教,使这次展览成为西方了解同济实践的重要展览事件。从倡导“建筑空间组合设计原理”教学体系开始,同济学派对现代建筑理性精神的执着坚持,成为当代中国建筑和建筑教育发展富有特色的重要一支。     

承前启后发展荷兰整体性长期规划——专访荷兰住房、空间规划与环境部国土规划司司长汉克·欧文科

王秋元(以下简称 W):请您阐述您的主要工作内容与任务,以及您的工作任务与"兰斯塔德环型城市2040远景"(以下简称"2040远景")的关系.