Session Overview
ID2 (cont): Multicriteria environmental perception
Thursday, 23/Jul/2015:
4:30pm - 6:00pm

Session Chair: Lutz Katzschner, University Kassel
Location: Spot Room


Physical load resulting from particulate matter, noise and thermal stress on inner-city public open space – An interdisciplinary analysis

Bastian Paas1,4, Isabell Maras1,4, Teresa Schmidt2,4, Jonas Stienen3,4, Christoph Schneider1

1Department of Geography, RWTH Aachen University, Germany; 2Communication Science, RWTH Aachen University, Germany; 3Institute of Technical Acoustics, RWTH Aachen University, Germany; 4Project house HumTec, RWTH Aachen University, Germany

Particulate matter (PM) is an important environmental risk to health. The major proportion of world’s population lives in cities, where exceedances of air quality standards occur regularly. Current research suggests that even short periods of time spent in locations with high PM concentrations, e.g. during commuting or relaxing, could have significant health impacts. However, further factors have to be taken into account when holistically investigating the physical load in urban spaces, e.g. stress resulting from noise, heat or cold. Planning and maintenance of urban areas require an integrative approach connecting methods from natural sciences, engineering and social sciences.

Field experiments were carried out at selected weekdays at 6 different locations in an inner-city public open space in the city of Aachen. The investigation site spans an area of about 0.02 km2 and is characterized by a well-attended inner city park, enclosed with buildings generally comprised of 4-5 floors. One of the most frequented roads by public transport buses and unsurfaced footpaths lead through the investigation area. Measurements have been conducted to determine air temperature, relative humidity, radiation temperature, 2-dimensional wind components, 3-dimensional solar and infrared radiation fluxes as well as mass concentration and number concentration of suspended particles with mobile sensors. Simultaneously, acoustic measurements capturing the sound pressure level at high temporal resolution and a questionnaire accounting for an overview of the perception of urban park users have been performed.

First results regarding air quality data highlight that locations in close vicinity to the main road showed lower mean PM10 concentrations (15.3 µg m-3, 14.4 µg m-3; n = 58) in comparison to several places inside the green area 150 m off the trafficked road (29.4 µg m-3, 24.9 µg m-3). In contrast, fine particle fractions were distributed differently. Nearly identical mean concentrations of PM1 were identified at all locations (6.0 µg m-3 to 6.9 µg m-3). Overall, PM concentrations followed a highly heterogeneous pattern at small scale, which leads to the assumption that unsurfaced footpaths inside the park played a significant role as a source of primary particles. As anticipated, when comparing air quality measurement data to sensation data it becomes obvious that particulate matter was not perceptible. Air quality perception seemed to be mainly driven be visible and audible occurrences or environmental circumstances. In contrast it can be stated that acoustic measurement data (i.e. psychoacoustic loudness), even as a mean value over the entire time span, compared to the results from the interview based questionnaire showed good agreement.

Further work focuses on the generation of simulation data by using numerical microclimate models (i.e. ENVI-met, Austal2000) as well as sound mapping tools. A comparison with measured data will be crucial to validate the ability of the modelling approaches for inner-city open space. Simulated data will enable a better understanding of the physical processes. It allows for a higher spatial resolution of the patterns behind physical stress factors. The approach provides an opportunity to obtain a conclusive picture regarding probable health impacts of future scenarios of re-designed open squares.

In a related paper by Maras et al. we analyze the versatile dataset from the perspective of observed and perceived thermal comfort.

Perception Studies on the Influence of Trees and Greens in Open Spaces for Environmental Quality

Taiwo Aderonke Ewulo1, Adeyela Ibironke Okunlola1, Ifeoluwa Adebowale Balogun2, Samuel Agele1

1Department of Crop, Soil and Pest Management, Federal University of Technology, Akure, Nigeria; 2Department of Meteorology, Federal University of Technology, Akure, Nigeria

Abstract- Trees within the campus have an important positive effect on people’s lives. One such positive effect is the amelioration of microclimate. The aim of this research is to assess the perception of people (staff and students) on the positive effects of trees and green spaces on the microclimate of their environment and how it affects the people in return. This perception study was carried within the campus of the Federal University of Technology; Akure to determine the influence of trees, greens in opens for a quality environment, their perception about the university landscape and how landscape and weather affect people. The survey indicated that over half of the respondents strongly agree that landscape provide comfort and contributes to environmental quality, while about half agreed to the statement that the university is beautifully landscaped with adequate trees. This study helps to explain that people enjoy the comfort of trees and greens in their environment.

Key words: Landscape, microclimate, greens, comfort

ID2 (cont)-2-5631120_a.pdf

Observation of urban climate variability at local scale and comparison with human perception

Noémie Gaudio1, Sabrina Marchandise2, Julien Le Bras1, Aude Lemonsu1, Sinda Haouès-Jouve2, Dominique Legain1

1CNRS/Météo-France, France; 2LISST-Cieu, Université Toulouse Jean Jaurès, France

Experimentally, the Urban Heat Island (UHI) is often studied at the scale of the entire city or by differentiating its effects according to homogeneous neighbourhoods. Nevertheless, the urban climate variability at very local scale may be of the same order of magnitude than at city scale. The neighbourhood is besides a quite interesting and challenging microclimate study field. The comprehension of microclimate variability and involved physical processes may open short-term perspectives regarding the local urban planning, with the double objective of improving thermal comfort while meeting as much as possible inhabitant expectations.

With this aim, an interdisciplinary field experiment associating researchers in meteorology and human and social sciences was carried out in a neighbourhood of the city of Toulouse (France). The area covered about 1 km x 0.5 km and was composed of different urban fabrics. From January to June 2014, a permanent network was setup, composed of ten weather stations recording near-surface temperature, humidity, wind speed and direction, and completed by a roof-level reference station in order to document larger scale atmospheric variables including the incoming short- and long-wave radiation. Also, three intensive observational periods were conducted in January, April and June 2014. For three successive days, every three hours, mobile measurements of temperature, humidity and wind were continuously recorded along a predefined itinerary through the neighbourhood, with a GPS recording associated. Moreover, black and grey globes were used to appreciate the “perceived” temperature. Finally, during “commented walks”, the inhabitants completed a social survey (simultaneously to measurements) about their feeling perception, especially in terms of thermal comfort.

The data analysis first focuses on the objective detection of a microclimate variability at this study scale, while considering the possible seasonal influences. It also addresses the issue of climatic atmosphere or “ambiance” through the coupling of different measured meteorological parameters, and the evaluation of a perceived temperature computed using grey globes. Finally, a first cross-analysis is proposed in order to put in perspective the environmental physical parameter measurements and the results of social surveys questioning people about their perception.

Influence of urban climate on perception responses in soundwalks: case study Aachen

Margret Sibylle Engel1,2, Janina Fels1, Christoph Schneider2

1Institute of Technical Acoustics, Medical Acoustics Group, RWTH Aachen University, Germany; 2Department of Geography, RWTH Aachen University, Germany

This work is part of a broader study on environmental factors influencing the amount of the cost of environmental noise in urban areas. The research is integrated into a project area called Urban Future Outline (UFO) at the Human Technolgoy Centre (HumTec) at RWTH Aachen University. The aim of the here presented study is to evaluate the influence of urban climate in the perception of the environment of answers from the following aspects: visual, auditory, climatic, cultural, emotional and economic. The method selected to collect perception data is the so-called method of “soundwalks” in which a group of people express their views on urban landscapes and their perception on soundscapes with the aid of a structured questionnaire. At the same time, the sound data was monitored with the aid of Sennheiser KE-3 microphones. Climate data for the days when soundwalks occurred were obtained by fixed stations of climate monitoring at RWTH Aachen University. To check the influence of urban climate on perceptual responses obtained through soundwalks nonparametric tests are calculated as follows: Spearman correlation coefficient for quantitative and Chi2 data, along with the V Cramer coefficient for qualitative data. In the contribution to ICUC we will present results regarding the influence of actual atmospheric conditions on pedestrians’ perception of other environmental factors and soundscapes for the study site of the city of Aachen.

ID2 (cont)-4-5171474_a.pdf

A methodological approach to the environmental quantitative assessment of urban parks

Pninit Cohen1, Oded Potchter1,2, Izhak Schnell1

1Tel Aviv University, Israel; 2Beit Berl Academic College, Israel

Pninit Cohen1,2, Oded Potchter1,3, Izhak Schnell1

1 Department of Geography and the Human Environment, Tel Aviv University, P.O. Box 39040, Tel Aviv, Israel

2 The Porter School of Environmental Studies, Tel Aviv University

3 Department of Geography and Environmental Development, Beit Berl Academic College, Israel.

This study proposes an integrative methodology for the environmental assessment of urban parks. Since most of the studies that have investigated the environmental effect of urban parks have focused on only one or two nuisances (air or noise pollution or thermal discomfort), a difficulty exists in evaluating the overall influence of an urban park on environmental quality. Moreover, the small numbers of studies that have tried to suggest methodological approaches for a quantitative environmental assessment of urban green spaces have not based their assessment methods on the analysis of in-situ objective measurements of air pollution, noise and climatic nuisances and their cumulative impact at a specific location. This methodology is a quantitative environmental assessment of the three major environmental nuisances that influence overall environmental quality at specific locations.

The methodology includes five stages: (1) in-situ measurements of air pollution, noise and climatic variables; (2) data analysis and indexing by standard indices (PET, AQI and noise classification); (3) data categorizing according to a common denominator of unified criteria; (4) accumulative assessment of the examined nuisances; and (5) classification and ranking of overall Environmental Quality Level (EQL) for the specific site according to the discomfort level for humans.

This method enables the identification of the dominant nuisance in the investigated sites in various seasons and provides a useful tool for urban planners and architects in the planning process, so as to achieve an ideal environmental quality for the benefit of urban inhabitants.

A case study, which examined the environmental quality level of an urban park, an urban square and a street canyon was conducted in Tel Aviv, Israel, showed the superior environmental quality level of the urban park in comparison to other urban open spaces, in both summer and winter.

Scientific practices within the urban climate research field: « Drastic interdisciplinary » between social and natural sciences

Géraldine Molina1, Anne Bernabé2, Valéry Masson3, Julia Hidalgo4

1IRSTV (FR CNRS 2488 – École Centrale de Nantes) - CERMA (ENSAN – UMR CNRS 1563); 2LEEHA (ECN – UMR CNRS 6598); 3GAME/CNRM, Météo-France & CNRS; 4LISST, Université Toulouse II - Le Mirail

Urban micro-climate is the perfect archetype of environmental concerns complexity. We propose a reflection on the scientific practices overturning when researchers invest this topic. The urban climate research field implies new compositions/relations between professional worlds: 1) between researchers and urban stakeholders 2) between researchers from different scientific traditions and disciplinary families unaccustomed to work together. In the last decade, interdisciplinary collectives of French researches developed studies on urban climate issues at different scales (city, city blocks, buildings, etc.) creating new interfaces between social sciences (sociology, anthropology, geography) and physical sciences or natural sciences (the atmospheric physics, urban engineering or building energy management). To explore the drastic interdisciplinary dynamics and reveal the mechanisms of "science in the making" (Latour, 1989), we did an investigation on the French research context on urban climate.

How those new interdisciplinary consortiums are organizing to challenge the emerging environmental concerns? To answer this central issue, our contribution is divided into three main steps.1) We first explain the scientific implications on the urban climate thematic. 2) From the feedbacks of researchers involved in this collective adventure, we identify the main issues, brakes and friction points observed in this drastic interdisciplinary meeting. 3) We finally point out the levers and facilitators to develop interdisciplinary dynamics (e.g. the overrun of mutual stereotypes, the establishment of a common language, or the proposal of innovative methodologies crossing physic phenomena and social dynamics).

Keywords: scientific practices, interdisciplinary dynamics, working methods, methodology, disciplinary identity, urban climate