SFB 1502:  Regional Climate Change: Disentangling the Role of Land Use and Water Management

Subject Area Geosciences
Agriculture, Forestry and Veterinary Medicine
Biology
Computer Science, Systems and Electrical Engineering
Social and Behavioural Sciences
Term since 2022
Project identifier Deutsche Forschungsgemeinschaft (DFG) - Project number 450058266
 

Project Description

Several continental regions on Earth are getting wetter, while others are drying out not only in terms of precipitation but also measured by the increase or decrease in surface water, water stored in the soils, the plant root zone, and in groundwater. Drying and wetting as seen in terrestrial, space-geodetic and remote sensing data are generally ascribed to combined effects of global warming due to greenhouse gas forcing, natural variability, and anthropogenic modification of the water cycle. Existing climate models that account for these effects fail to explain observed patterns of hydrological change sufficiently. Contrary to common beliefs, observations also do not support a simple dry-gets-dryer and wet-gets-wetter logic. Instead, the observed trends, e.g. in precipitation, soil moisture, water storage, or flood discharge, differ considerably from a simplified logic. The CRC targets at closing this gap of understanding. To better comprehend the origin of these patterns, it is necessary to build a modeling framework that explains past observations as realistically as possible, accounts for potential drivers of change that may have been understudied in the past, and that can predict future changes.Climate change and anthropogenic interactions are already affecting the frequency of extreme events such as heat waves, droughts and floods. For example, more intense, more frequent, and longer-lasting heat waves are projected for the 21st century; surface and ground water buffer the effects of such heat waves, but large-scale drying may amplify them to an as yet unknown extent. Societal, environmental and economic consequences include increased risk in agricultural production, threats to agricultural productivity and food security and increasing health risks. This CRC proposes the hypothesis that humans – through several decades of land use change, and intensified water use and management – have caused persistent modifications in the coupled land and atmospheric water and energy cycles. These human-induced modifications contribute considerably, compared to greenhouse gas (GHG) forcing and natural variability, to the observed trends in water storage at the regional scale. We hypothesize that land management and land and water use changes have modified the regional atmospheric circulation and related water transports. These changes in the spatial patterns of the water balance are hypothesized to have created and magnified imbalances that lead to excessive drying or wetting in more remote regions. We test this hypothesis for a single, continental-size region in the 1st phase (Europe/Eurasia). In later phases, we evaluate the transferability of our approach for regions with different environmental conditions. We propose to develop evidence-based sustainability criteria for land and water use activities.
DFG Programme Collaborative Research Centres

Current projects

Completed projects

Applicant Institution Rheinische Friedrich-Wilhelms-Universität Bonn
Participating University Georg-August-Universität Göttingen; Universität zu Köln
Participating Institution Deutscher Wetterdienst (DWD); Forschungszentrum Jülich
Spokesperson Professor Dr.-Ing. Jürgen Kusche