No place for climate change

Transdisciplinary study on climate change adaptation of urban squares

Climate change is not only taking place on distant continents or far into the future, but here and now. In Germany, too, the temperature is rising – and even faster than the global average – and the number of hot days is increasing. Especially in cities, the heat and thus the negative consequences for health and quality of life are clearly noticeable. Urban squares that serve as public recreation areas for residents and visitors must therefore be greener and more diverse in future if they are to remain usable.

A Heidelberg research team led by Dr. Kathrin Foshag has investigated the heat stress in selected urban squares in Heidelberg and identified adaptation measures that can be taken. The results of the project “Viability of public spaces in cities under increasing heat: a transdisciplinary approach” have now been published in the journal “Sustainable Cities and Society”.

Kathrin Foshag)
Fig. 1 Aerial view of Heidelberg's old town with the University square (photo: Kathrin Foshag)

The research focused on the university square in the historic old town and the “Schwetzinger Terrasse” in the newly built passive house district “Bahnstadt”. Meteorological parameters such as temperature, wind speed and humidity were recorded in summer 2018 to analyse the current situation. The “Schwetzinger Terrasse” was particularly affected by very high temperatures; surface colour and texture play an important role. Green areas provide for a temperature regulation, but only in a vital state. In a further step, the solar irradiation on the sites was modelled using geoinformatics methods. The technique enables the simulation of different shading measures with trees or solar sails and demonstrates how the small-scale climate at a site can be positively influenced. In this way, the irradiation can be reduced by half.

Actual and possible future situation and solar potential for Schwetzinger Terrace. Values are solar potential summed up over the entire summer (June through August 2018) for Schwetzinger Terrace in the sustainable district Bahnstadt, Heidelberg. A Modelled solar potential for the current state, B Aerial photograph of the Schwetzinger Terrace, summer 2018, showing the barely existing shade, C Visualization of the adapted future state with fully developed vegetation and artificial shading measures, D Modelled solar potential for the assumed adapted future state
Fig. 2 Actual and possible future situation and solar potential for Schwetzinger Terrace. Values are solar potential summed up over the entire summer (June through August 2018) for Schwetzinger Terrace in the sustainable district Bahnstadt, Heidelberg. A Modelled solar potential for the current state, B Aerial photograph of the Schwetzinger Terrace, summer 2018, showing the barely existing shade, C Visualization of the adapted future state with fully developed vegetation and artificial shading measures, D Modelled solar potential for the assumed adapted future state.

“When measuring during the summer months, we noticed that only a few people use the two places to stay. On the basis of questionnaires and so-called mental maps, we asked passers-by and residents about the reasons,” reports Dr. Kathrin Foshag. It was noticeable that the desire to adapt to the heat in the city goes hand in hand with the need for attractive and functional design, greenery and variety in the squares. These findings enabled the researchers to develop solutions in cooperation with local experts.

The work is both inter- and transdisciplinary, i.e. the information gathered using natural and social science methods was decisively enhanced with knowledge from local stakeholders. This is essential to check and ensure the feasibility of the measures. In this project, cooperation with municipal offices was of particular importance, above all with the City of Heidelberg‘s Office of Environmental Protection, Trade Supervision and Energy represented by Dr. Raino Winkler, one of the co-authors of the paper.

The publication is based on the doctoral thesis of Dr. Kathrin Foshag within the framework of the BMBF-funded heiEDUCATION project at the Heidelberg School of Education (HSE), which, in addition to funding the doctoral project, has made Open Access publication possible. Dr. Kathrin Foshag is embedded in a consortium consisting of Dr. Nicole Aeschbach (TdLab Geography at the Institute of Geography, Heidelberg University), Prof. Dr. Bernhard Höfle (3DGeo Group, Department of Geoinformatics at the Institute of Geography, Heidelberg University), Prof. Dr. Alexander Siegmund (Research Group for Earth Observation (rgeo) and UNESCO Chair on World Heritage and Biosphere Reserve Observation and Education, Heidelberg University of Education and Institute of Geography, Heidelberg University) and Prof. Dr. Werner Aeschbach (Institute of Environmental Physics, Heidelberg University).

The publication is of particular importance for the new TdLab Geography, for which Dr. Kathrin Foshag is working as a postdoctoral fellow. The Transdisciplinarity Laboratory, which was launched by Dr. Nicole Aeschbach in autumn 2018, aims to apply the transdisciplinary approach, which has so far been mainly based on the social sciences, to all subject areas of geography. The focus of the research is the area “Geographies of Climate Change”. From the very beginning of the research process, scientists and non-academic researchers work together on the research question (co-design), contribute their own knowledge and perspectives and jointly develop analyses, concepts and solutions. In this way, new transformation knowledge is produced based on system and target knowledge. Ideally, the results of the projects are applied both in research and in practice; they therefore range from the development of methods and recommendations for action to joint implementation.

Publication

Foshag, K., Aeschbach, N., Höfle, B., Winkler, R., Siegmund, A., Aeschbach, W., 2020: Viability of public spaces in cities under increasing heat: A transdisciplinary approach, Sustainable Cities and Society, Volume 59, August 2020, 102215, https://doi.org/10.1016/j.scs.2020.102215