As discussed by EGU2017 DB2 and EGU 2018 TM16, there had been an impressive series of international agreements and development of large networks of cites that call for qualitative improvements of urban systems and their interactions with their environment. The main goal of this ITS is to mobilise geoscientists, highlight their present contributions and encourage holistic approaches beyond the traditional silos of urban meteorology/hydrology/climatology/ecology/resilience, as well as some other terms.

Public information:
See also Town Hall TM 19 "Cities and Interdisciplinary Geosciences"
to be held on Thursday 11 April in room 1.85 from 19:00 to 20:00.
https://meetingorganizer.copernicus.org/EGU2019/session/33913

2007 was a crucial year when the threshold of 50% of the population living in urban areas has been achieved and Ten years later, many hazards and often combination of hazards heat the urban environment everywhere in the world. This increase rate corresponds to a new city of 1 million people every week during the next 40 years. This exponential curve is enough to imagine that cities become more vulnerable: issues we will have to face dealing with risk management become more complex. Moreover, this quick urbanization comes with climate change uncertainties. Climate change, coupled with people and asset concentration in cities, is the worst combination to set up a sustainable natural hazard management plan. As an example, floods are considered the major natural hazard in the EU in terms of risk to people and assets. Currently, more than 40 bn € per year are spent on flood mitigation and recovery in the EU. More than 75 % of the damage caused by floods is occurring in urban areas. Climate change and concentration of population and assets in urban areas are main trends likely to affect these numbers in the near future. Global warming is expected to lead to more severe storm and rainfall events as well as to increasing river discharges and sea level rise. This means that flood risk is likely to increase significantly. At least, urban systems contain assets of high value and complex and interdependent infrastructure networks (i.e. power supplies, communications, water, transport etc.). The infrastructure networks are critical for the continuity of economic activities as well as for the people’s basic living needs. Their availability is also required for fast and effective recovery after disasters (floods, hurricanes, earthquakes, landslides...). The severity of damage therefore largely depends on the degree that both high value assets and critical urban infrastructure are affected, either directly or indirectly.
In this context, we obtain an urban society:
• more and more menaced by a lot of hazards
• more and more vulnerable due to increasing issues and complex urban system relations;
• less and less resilient.

This session aims at discussing how researchers, practitioners and professionals are integrating the resilient concept to set up new risk management approaches and to design more resilient and flexible cities to face all types of natural hazards. Indeed, a lot of projects in the EU are now trying to use the concept of resilience to mitigate different types of risks in urban areas. This session represents a great opportunity to exchange on resilient cities and to build up a resilience framework. We are attending presentations combining different disciplines, bringing conceptual elements on resilience but also tangible applications. All methods, frameworks, tools (GIS) designed to reduce risks in cities and integrating the resilience concept are welcome in this session.

From the Urban Resilience Studies part, we are expecting communications questioning the traditional risk management approaches, based on case studies and leading to new approaches based on the concept of resilience.
From the Risk Mapping, communications have to demonstrate how risks are characterized, assessed and mapped at several scales allowing to develop operational spatial decision support systems.

Cities all over the world are facing rising population densities. This leads to increasing fractions of built-up and sealed areas, consequencing in a more and more altered and partly disrupted water balance - both in terms of water quantities and qualities. On top, climate change is altering precipitation regimes.

This session focuses on according urban ecohydrological problems and approaches to solve them spanning from technical to nature-based solutions in different time and spatial scales from the building to the whole city.