CRC1502 Regional Climate Change: Disentangling the Role of Land Use and Water Management - 2022 to 2025

CRC1502 Regional Climate Change: Disentangling the Role of Land Use and Water Management

While several continental regions on Earth are getting wetter, 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. Observations, however, do not support a simple dry-gets-dryer and wet-gets-wetter logic and existing climate models fail to explain observed patterns of hydrological change sufficiently. This CRC tests the hypothesis that humans – through decades of land-use change and intensified water use and management – have caused persistent modifications in the coupled water and energy cycles of land and atmosphere. Compared to greenhouse gas (GHG) forcing and natural variability, these human-induced changes contribute considerably to the observed trends in water storage at the regional scale. We hypothesize that – next to known local effects – human land management, land and water use changes have altered the regional atmospheric circulation and related water transports. These changes in the weather balance’s spatial patterns have, it is hypothesized, created and amplified imbalances that lead to excessive drying or wetting in more remote regions..

Objectives of sub-project C05 Towards a dynamic representation of irrigation in land surface models at University of Göttingen
Water use for irrigation has a strong impact on water storages in aquifers, reservoirs, soil and atmos-phere as well as on fluxes between the storages, in particular evapotranspiration. The main objective of subproject B05 is to introduce dynamics in irrigated area and irrigated crops into land surface models, in particular differences between dry and wet years. Improved implementation of irrigation water use in the CRC IMS will help to better quantify human impacts on the water cycle and on energy fluxes and thus considerably contribute to the CRC’s key objectives.

Persons in charge:
Dr. Wanxue Zhu
Malte Weller
Prof. Dr. Stefan Siebert

Project duration:
1st January 2022 to 31st of December 2025

DFG (project number: 450058266)

CRC1502 - Project website

University of Bonn
University of Cologne
Research Center Jülich
German Meteorological Service