Georgia Destouni Foto: Cecilia Bruzelius
Georgia Destouni Photo: Cecilia Bruzelius
 
Changes in water evaporation and water transpiration by vegetation in the landscape (together called evapotranspiration) affect water circulation, water availability, and climate change. How water conditions have changed over time, and what changes may occur in the future, depends to a large degree on how our food and energy production uses water and changes its circulation in the landscape.
“Our results show how agricultural and hydropower developments change evapotranspiration in a landscape. During the 20th century, such effects have been as important globally as those of direct agricultural irrigation, deforestation, and atmospheric changes in temperature and precipitation,” says Georgia Destouni, professor of Hydrology at the Department of Physical Geography and Quaternary Geology and principal investigator of the study.
 
To understand how different change drivers may impact water and climate changes in the future, we need to understand how large impact they have had in the past, and why. In this study, 20th century data from nine major Swedish water catchments have been analysed and compared with other, regional and global, results in order to study the effects of different human activities on water and climate.
 
Previous studies have mostly focused on describing and accounting for water effects from temperature and precipitation changes, deforestation, and direct human water use for irrigation. This study shows that similar large water effects are caused by non-irrigated agriculture and hydropower developments. Models and analyses of water and climate change must therefore also consider these change drivers and effects.
“Our study emphasizes the need for further development of climate and Earth System models. They need to better represent and account for how developments and changes in our food and energy production use and change the water in the landscape, and thereby, contribute to future climate change,” says Georgia Destouni.
 
For further information
Georgia Destouni, professor of Hydrology, Dept. of Physical Geography and Quaternary Geology, Stockholm University, phone +46-8-16 47 85, mobile phone +46-704-53 23 66, e-mail georgia.destouni@natgeo.su.se