Model-based Global Assessment of Hydrological Pressure

Climate change will likely lead to increased frequency and intensity of extreme natural events such as storms, floods, droughts and heat waves, as stated in several IPCC reports. Even in today’s climate, the knowledge on which extremes to anticipate is insufficient in several parts of the world. Despite major advances in terms of climate natural variability, future projections, impact studies, services and adaptation research related to the occurrence of natural hazards, use of this knowledge in societal planning is still limited. Klein and Juhola identify five bottlenecks for the use of research knowledge in climate adaptation decisions: (i) that scientists use theoretical concepts that do not meet stakeholders' reality, (ii) uncertainties in predictions of climate impacts, (iii) the difference in the geographic scale of climate data and stakeholder needs, (iv) the need to manage natural variability already in today's climate, and (v) that climate adaptation is just one of several factors that stakeholders need to consider. This means that stakeholder perspectives on the use and relevance of available climate information, as well as the broader decision-making context in which adaptation decisions are to be made, need to be considered.
The impacts of climate change and variability on hydrological systems may expressed in different time and space scales, from hours to decades and from km2 to continental scales. In the extreme small-scale end of the spectrum, there is flash floods and debris flow caused by short-duration extreme rainfall intensities. Recent global disasters include Texas 2017 and Tokyo 2015 and also in the Nordic region severe floods have recently occurred (e.g. Copenhagen 2011 and Malmö 2014) In the other end, the hydrological effects of droughts may be long lasting and affect large areas, especially when the ground water is impacted. The consequences may require emergency acts as in the case of the failure of water distribution to cities or of hydropower production. Such cases have been experienced recently both in S.-E. Brazil 2015 (water distribution failure in São Paulo) and in S. Sweden 2017. Both short/small- and long/large-scale hydrological hazards are currently simulated and forecasted, however this information does not reach stakeholders. There is a need for a bottom-up approach where stakeholders are involved in the development of tools that translate model results into useful information.

Climate change will likely lead to increased frequency and intensity of extreme natural events such as storms, floods, droughts and heat waves, as stated in several IPCC reports. Even in today’s climate, the knowledge on which extremes to anticipate is insufficient in several parts of the world. Despite major advances in terms of climate natural variability, future projections, impact studies, services and adaptation research related to the occurrence of natural hazards, use of this knowledge in societal planning is still limited. Klein and Juhola identify five bottlenecks for the use of research knowledge in climate adaptation decisions: (i) that scientists use theoretical concepts that do not meet stakeholders' reality, (ii) uncertainties in predictions of climate impacts, (iii) the difference in the geographic scale of climate data and stakeholder needs, (iv) the need to manage natural variability already in today's climate, and (v) that climate adaptation is just one of several factors that stakeholders need to consider. This means that stakeholder perspectives on the use and relevance of available climate information, as well as the broader decision-making context in which adaptation decisions are to be made, need to be considered.
The impacts of climate change and variability on hydrological systems may expressed in different time and space scales, from hours to decades and from km2 to continental scales. In the extreme small-scale end of the spectrum, there is flash floods and debris flow caused by short-duration extreme rainfall intensities. Recent global disasters include Texas 2017 and Tokyo 2015 and also in the Nordic region severe floods have recently occurred (e.g. Copenhagen 2011 and Malmö 2014) In the other end, the hydrological effects of droughts may be long lasting and affect large areas, especially when the ground water is impacted. The consequences may require emergency acts as in the case of the failure of water distribution to cities or of hydropower production. Such cases have been experienced recently both in S.-E. Brazil 2015 (water distribution failure in São Paulo) and in S. Sweden 2017. Both short/small- and long/large-scale hydrological hazards are currently simulated and forecasted, however this information does not reach stakeholders. There is a need for a bottom-up approach where stakeholders are involved in the development of tools that translate model results into useful information.