Improved concepts and methods in analysis and evaluation of the urban climate for optimizing urban planning processes

Planning processes are strongly influenced by an increased awareness of environmental issues concerned by projected land-use transformations. A research project was carried out to produce climate maps for the region of Basel/Switzerland to enable planning authorities taking care of the urban climate and its interrelations with urban structures. Main focus was given to develop and implement a methodology meeting not only the regional requirements of Basel. The new approach is not depending on subjective criteria or manual interventions and ensures its applicability for other regions. Three basic concepts were developed or improved in this study. A new definition of `climatopes’ was introduced, and methods were developed for their digital determination by objective criteria. This definition of climatopes requires adequate information on land-use, which is provided by introducing the concept of `areal types'. In contrast to `traditional’ land-use classes directly derived from satellite images, areal types are complex aggregates reflecting not only different physical surface properties, but also socioeconomic aspects of land-use. `Ventilation classes’ are the second component required to delineate climatopes. They summarize the combined influencing factors of terrain features and land-use structures on wind field and urban ventilation. Their determination is based on topographic information and surface properties derived from a digital terrain model and from land-use data. The spatial distribution of climatopes was computed for Basel. Various quality assessment procedures and the application of climatopes for an automated generation of planning guidelines demonstrate the applicability of the concepts. Climate maps containing the results of the analysis and evaluation of the urban climate of Basel were estimated by the involved planners to be a valuable tool meeting their practical requirements to a high degree.     

Automated classification of planning objectives for the consideration of climate and air quality in urban and regional planning for the example of the region of Basel/Switzerland

The project ‘Climate Analysis of the Region of Basel’ (KABA) was carried out in cooperation with several planning authorities to produce climate analysis and planning recommendation maps at scales of 1 : 100,000 and 1 : 25,000. These maps enable urban and regional planners to estimate impacts of land-use changes on local climate and air quality. Conceptual numerical models receiving spatially distributed input data from a geographic information system derived the information content of the maps. By introducing novel concepts concerning land-use and ventilation, the dominant controls for local climate and air quality, automated, knowledge-based classification schemes for climate analysis were developed and applied. The same model technique was utilized for a spatially distributed assignment of planning objectives to the study region. Three different problem sections are considered: ventilation, air quality and thermal situation. Several planning objectives were distinguished within each problem section, and each element of a 100 m grid was individually evaluated by automated, knowledge-based classification procedures. This approach provides a high degree of transparency and objectivity in place of subjective (and thus irreproducible) assessments by experts. Transfer of the procedures to other regions could be successfully demonstrated in a project named ‘Climate Analysis Maps for Planning Aspects of Solothurn/CH (CAMPAS/CH)’ funded by European Space Agency. Hence, the approach is of general interest, at least for many densely populated regions at mid-latitudes.     

The study of urban metabolism and its applications to urban planning and design

Following formative work in the 1970s, disappearance in the 1980s, and reemergence in the 1990s, a chronological review shows that the past decade has witnessed increasing interest in the study of urban metabolism. The review finds that there are two related, non-conflicting, schools of urban metabolism: one following Odum describes metabolism in terms of energy equivalents; while the second more broadly expresses a city's flows of water, materials and nutrients in terms of mass fluxes. Four example applications of urban metabolism studies are discussed: urban sustainability indicators; inputs to urban greenhouse gas emissions calculation; mathematical models of urban metabolism for policy analysis; and as a basis for sustainable urban design. Future directions include fuller integration of social, health and economic indicators into the urban metabolism framework, while tackling the great sustainability challenge of reconstructing cities.     

Analysis of some organochlorine pesticides in an urban atmosphere (Strasbourg, east of France)

High volume samples of urban air have been collected in Strasbourg, a big city situated in the east of France, for the evaluation of the contamination by organochlorine pesticides. Pesticides (p,p'-DDT, p,p'-DDD, p,p'-DDE, aldrin, dieldrin, endrin, gamma-HCH, cis-chlordane, trans-chlordane, alpha-endosulfan, beta-endosulfan, hexachlorobenzene, heptachlor and some of their metabolites: alpha-HCH, 2,4'-DDT, 2,4'-DDD and 2,4'-DDE) were analysed by GC-ECD. Prior to analysis, samples were Soxhlet extracted with a mixture of n-hexane/methylene chloride. The analysis of samples collected in 2001 (n = 6), 2002 (n = 7) and 2003 (n = 5) shows that alpha-HCH and gamma-HCH were detected in all samples (between 0.05 and 4 ng m(-3) and between 0.01 and 1 ng m(-3), respectively) along with aldrin and dieldrin at lower concentrations (between 0.01 and 0.08 ng m(-3) and between 0.02 and 0.09 ng m(-3), respectively). Other pesticides were detected very randomly at very low concentrations. The calculation of the alpha/gamma-HCH ratio shows that hexachlorocyclohexane measured in the atmosphere have a local origin and come probably from contaminated soil by volatilisation. alpha and beta-endosulfan were practically not detected in samples collected in 2001 and 2002 while they were always measured in the gas phase in samples from 2003. This observation can be explained by an increase of volatilisation with the increase of the air temperature. In July, temperature were higher (between 17 and 30 degrees C in climatic station) than in March-May 2001 and 2002 (between 2 and 19 and between 2 and 10, respectively).     

Spatial variation of DDT and its metabolites in fish and sediment from Cinca River, a tributary of Ebro River (Spain)

The Cinca River is a tributary of Ebro River in the NE of Spain which receives input from different activities. One of the most important is related to an industry where DDT is used as an intermediate in the production of dicofol. This study evaluated the DDT contamination along the Cinca River. Sampling sites were selected up- and downstream from this industry. Sediments and fishes (59 bleaks (Alburnus alburnus) and 23 barbels (Barbus graellsi)) were collected in 2002 and analyzed using a new and rapid selective pressurized liquid extraction (SPLE) method. DDT and its metabolites were found in sediments and fishes at levels ranging from 9 to 94microg kg(-1) dry weight (d.w.) and from not detected to 2098microg kg(-1) wet weight (w.w.), respectively. The highest values corresponded to samples collected just downstream the industry. Thirty kilometers downstream from the factory, levels were clearly lower, showing a weakening of the impact. p,p'-DDE isomer comprised up to 50% and 70% of total DDT measured in sediment and fish, respectively. When compared with values obtained in a previous study in 1999, a generalized drop of the levels in all matrixes (77-97%), was observed. No meaningful differences were found between the two fish species studied neither between the two tissues (muscle and liver) analyzed.     

Characterization of particulate polycyclic aromatic hydrocarbons in the east of France urban areas

Background

Air samples collected on three different urban sites in East of France (Strasbourg, Besan?on, and Spicheren), from April 2006 to January 2007, were characterized to measure the concentrations of polycyclic aromatic hydrocarbons (PAHs) in the particulate phase (PM₁₀) and to examine their seasonal variation, diurnal variations, and emission sources.

Results

The average concentrations of ??PAHs were 12.6, 9.5, and 8.9?ng?m^?3 for the Strasbourg, Besan?on, and Spicheren sites, respectively. Strong seasonal variations of individual PAH concentrations were found at the three sampling sites, with higher levels in the winter that gradually decreased to the lowest levels in the summer. The diurnal variations of PAH concentrations in summer presented highest concentrations during the morning (04:00?C10:00) and the evening (16:00?C22:00) times, indicating the important contribution from vehicle emissions, in the three sampling sites. Furthermore, the ratio of BaP/BeP suggests that the photochemical degradation of PAHs can suppress their concentrations in the midday/afternoon (10:00?C16:00), time interval of highest global irradiance. In winter, concentrations of PAH were highest during the evening (16:00?C22:00) time, suggesting that domestic heating can potentially be an important source for particulate PAH, for the three sampling sites.

Conclusion

Diagnostic ratios were used to identify potential sources of PAHs. Results showed that vehicle emissions may be the major source of PAHs, especially in summer, with a prevalent contribution of diesel engines rather than gasoline engines at the three sites studied, independently of the seasons.     

Time trends in the concentrations of lead in wet precipitation from rural and urban sites in Austria

Trend and time series analysis of concentrations of lead in wet precipitation at different rural and urban sampling sites in Austria, collected during intervals of 6-12 years (between 1984 and 1995) is performed. A substantial decrease of the lead concentrations for all sites in consideration is observed similar to observations in Germany, Sweden and North sea and western Atlantic regions. Reductions in rural sites between 60 and 80% in 10 years and around 90% in 10 years in urban areas are found. This trend correlates with the reduction of lead emissions from combustion of gasoline. The seasonal deconvolution model of the data set reveals a typical seasonality with lead concentration peaks in summer and spring for the rural sites and winter peaks for urban sites. The average annual lead concentration in the rural region for 1995 was 1.25 micrograms/l, in the urban region 2.25 micrograms/l.     

Seasonal evolutions of ozone (O3) and its nitrogen precursors (NO, NO2) in urban Sfax (Tunisia)

Seasonal evolution of ozone (O3) and its nitrogen precursors (NO, NO2) in downtown Sfax (Tunisia) was monitored. Nitrogen oxides are shown to be closely related to local vehicle sources. Seasonal ozone levels, however, are shown to be dependent on regional meteorological conditions. High ozone levels are due to the effect of anticyclones and stratosphere intrusions (cut-off lows). Low levels are associated with cyclonic conditions of small vertical range of motion. Other than these particular conditions, ozone levels are shown to be relatively higher in fall and winter seasons, characterised by a very steady atmosphere. Overall, the examined meteorological conditions, the ozone concentrations observed in downtown Sfax are characterised by clear day/night cycles, which can be explained by the significant ventilation of the region.     

Long-term assessment of the wet precipitation chemistry in Austria (1984-1999)

The aim of the present study was to determine the long-time trends in concentrations and depositions of major ions in wet precipitation samples collected at 11 sampling sites from the Austrian precipitation chemistry network in the period 1984-1999. The analytical results were treated by the use of least square linear regression method. It is shown that a serious decrease of sulfate (between 30% and 60% for the period) and hydrogen ion (between 60% and 102% for the period) concentrations and depositions is achieved at almost all sampling sites and in most of these cases the linear trend proves to be statistically significant. Nitrogen containing ions and base cations do not reveal a distinct trend of changing and in the majority of the sites the linear models are not adequate. In principle, an overall slight concentration and deposition decrease for these major ions is observed (up to 30% for the period of observation) but some substantial exceptions are also found (site Haunsberg or site Lobau). The changes in chloride concentration and deposition, too, do not indicate significant linear trend and, in general, are decreasing for the period of monitoring. In order to give some explanation of the exceptional behaviour of some of the major ions in several sites, an additional comparison with Austrian emission data (sulfur dioxide, nitrogen oxides, ammonium) and with data from five EMEP sites from neighbouring countries is performed. A significant West-East trend of acidity increase is found as well as a good correlation with the emission trends. Therefore, both transboundary and specific local factors could be substantial factors in the wet precipitation chemistry in the region.     

Peroxyacetyl nitrate (PAN) in the urban atmosphere

Peroxyacetyl nitrate (PAN) in air has been well known as the indicator of photochemical smog due to its frequent occurrences in Seoul metropolitan area. This study was implemented to assess the distribution characteristics of atmospheric PAN in association with relevant parameters measured concurrently. During a full year period in 2011, PAN was continuously measured at hourly intervals at two monitoring sites, Gwang Jin (GJ) and Gang Seo (GS) in the megacity of Seoul, South Korea. The annual mean concentrations of PAN during the study period were 0.64 ± 0.49 and 0.57 ± 0.46 ppb, respectively. The seasonal trends of PAN generally exhibited dual peaks in both early spring and fall, regardless of sites. Their diurnal trends were fairly comparable to each other. There was a slight time lag (e.g., 1 h) in the peak occurrence pattern between O₃ and PAN, as the latter trended to peak after the maximum UV irradiance period (16:00 (GJ) and 17:00 (GS)). The concentrations of PAN generally exhibited strong correlations with particulates. The results of this study suggest that PAN concentrations were affected sensitively by atmospheric stability, the wet deposition of NO₂, wind direction, and other factors.     

Development and validation of the planktonic index of biotic integrity (P-IBI) for Qin River,a main tributary of the Yellow River in China

Environmental Science and Pollution Research - To evaluate the ecosystem health of Qin River, a main tributary of the Yellow River, a planktonic index of biotic integrity (P-IBI) that includes...     

An approach for treating the uncertainties in the impact of climate change

Past accumulated data supported by the predictions of climate models suggest that our world is getting warmer. Scientists are trying to construct mathematical models of both climate and crop systems to identify what types of climate changes could constitute a significant risk or benefit for agriculture. However, due to the many uncertainties regarding these models, it is impossible to make unequivocal predictions. At present, almost all the research in this area is carried out without considering the uncertain nature of the problem. The approach outlined here attempts to find a way to deal with the above uncertainty problem. Artificial intelligence techniques are being developed with the aim of performing inferences based on uncertain information. In our method, causal graphs are used for explicit representation of the relationships between climatic factors and yield. Probabilities are used to express the uncertainties associated with these links, and Bayes' theorem is applied to deal with uncertainty reasonings. This approach has the additional advantage of allowing the prediction to be readily updated as results from improved climate and crop models become available. These opportunities are being evaluated initially by using the model for potato growth developed at the Scottish Crop Research Institute.     

Opinions of 12 to 13-year-olds in Austria and Australia on the concern,cause and imminence of climate change

Early adolescence (12–13 years old) is a critical but under-researched demographic for the formation of attitudes related to climate change. We address this important area by exploring adolescent views about climate change. This paper presents opinions collected from surveys of 463 1st-year secondary school students (12–13 years old) in public secondary schools in inner-urban centres in Austria and Australia on whether climate change is (1) something about which to worry, (2) caused by humans and (3) happening now. Eligible respondents in both countries showed similar levels of agreement that climate change was probably or definitely something we should (1) worry about (84.6% Austria, 89.1% Australia), which is significantly higher than either country’s adult population. Eligible respondents agreed that climate change probably or definitely is (2) caused by humans (75.6% Austria, 83.6% Australia) and that climate change is probably or definitely something that is (3) happening now (73.1% Austria, 87.5% Australia). Their response differed from the respective adult populations, but in opposite directions. Our results suggest that socio-cultural worldview may not have as much influence on this age group as it does on the respective adult populations and suggests that this age group would be receptive and ready for climate science education and engagement initiatives.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01356-2) contains supplementary material, which is available to authorized users.     

Balancing urban growth and ecological conservation: A challenge for planning and governance in China

China has high biodiversity and is rapidly urbanizing. However, there is limited understanding of how urban expansion in the country is likely to affect its habitats and biodiversity. In this study, we examine urban expansion patterns and their likely impacts on biodiversity in China by 2030. Our analysis shows that most provinces are expected to experience urban expansion either near their protected areas or in biodiversity hotspots. In a few provinces such as Guangdong in the south, urban expansion is likely to impinge on both protected areas and biodiversity hotspots. We show that policies that could facilitate the integration of natural resource protection into urban planning exist on paper, but the prevailing incentives and institutional arrangements between the central and local governments prevent this kind of integration. Removing these obstacles will be necessary in order to safeguard the country’s rich biodiversity in light of the scale of urbanization underway.     

以河道水为原水的高速过滤过程及其性能分析

针对平原城市缓流河道普遍存在的季节性水质恶化问题,采用预氧化、微絮凝+高速过滤对天津市某缓流河道水体进行中试规模实验。结果表明,该处理技术具有处理周期长(>24 h)、过滤滤速高(平均为43.26 m·h-1)和出水效果好(出水水质优于地表水Ⅳ类水质标准)的特点。同时发现：单位面积滤柱的产水率呈“阶梯”下降趋势;高速过滤的堵塞特征曲线服从三次多项式分布;系统过滤历经增长期、稳定期和衰减期,其中增长期为3~4 h,稳定期约14 h,过滤系数λ为(0.020 1±0.001 3) cm-1(置信度P=95%),其可作为系统基本属性的定量参数。     

Polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs) in urban air and deposition in the United Kingdom

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) have been monitored in air and deposition at four UK urban sites (London, Cardiff, Manchester and Stevenage) since the beginning of 1991; data from the first 2 years are presented here. Median Σ2,3,7,8-substituted PCDD/F concentrations in air were 3.2, 4.0, 3.5 and 2.6 pg/m³ respectively for London, Cardiff, Manchester and Stevenage. Median Σ2,3,7,8-substituted PCDD/F deposition fluxes were 1.5 ng/m²/day in London, 1.4 ng/m²/day in Cardiff and Manchester and 0.79 ng/m²/day in Stevenage. Seasonal variations in the PCDD/F concentrations were observed at all sites for both air and deposition, with concentrations/fluxes generally elevated during the winter.