TY - JOUR
T1 - Data-driven regionalization of river discharges and emergent land cover-evapotranspiration relationships across Sweden
AU - Van Der Velde, Ype
AU - Lyon, Steve W.
AU - Destouni, Georgia
PY - 2013/3/27
Y1 - 2013/3/27
N2 - [1] Changes in river discharge and river water quality, due to climate change and other drivers such as land cover change, pose both societal and ecosystem threats. Analyses of measured terrestrial river fluxes are key for identifying the drivers and quantifying the magnitudes of such riverine changes. In this paper, we develop and apply a data-driven regionalization approach using the dense network of discharge measurements in Sweden. The developed regionalization approach facilitates detailed mapping of discharges (Q) and change trends in Q across Sweden. Combining these with estimates of precipitation (P) and change trends in P, we estimated actual evapotranspiration (AET) and change trends in AET via catchment-scale water balance constraints. We identified characteristic land cover-evapotranspiration relationships by plotting water use efficiency (AET/P) against energy use efficiency (AET/potential ET) for areas with unique land cover across Sweden. Our results show that wetlands have clearly lower water and energy use efficiencies compared to open waters, forests, and agriculture, and that agriculture has water and energy use efficiencies closest to those of open waters. We further compared the data-driven regionalization estimates of different water balance components with estimates of regional climate models (RCMs). The RCMs do not describe well the observed change trends in Sweden. In particular, for evapotranspiration, the observed change trends are not reproduced by any of the investigated 24 RCMs.
AB - [1] Changes in river discharge and river water quality, due to climate change and other drivers such as land cover change, pose both societal and ecosystem threats. Analyses of measured terrestrial river fluxes are key for identifying the drivers and quantifying the magnitudes of such riverine changes. In this paper, we develop and apply a data-driven regionalization approach using the dense network of discharge measurements in Sweden. The developed regionalization approach facilitates detailed mapping of discharges (Q) and change trends in Q across Sweden. Combining these with estimates of precipitation (P) and change trends in P, we estimated actual evapotranspiration (AET) and change trends in AET via catchment-scale water balance constraints. We identified characteristic land cover-evapotranspiration relationships by plotting water use efficiency (AET/P) against energy use efficiency (AET/potential ET) for areas with unique land cover across Sweden. Our results show that wetlands have clearly lower water and energy use efficiencies compared to open waters, forests, and agriculture, and that agriculture has water and energy use efficiencies closest to those of open waters. We further compared the data-driven regionalization estimates of different water balance components with estimates of regional climate models (RCMs). The RCMs do not describe well the observed change trends in Sweden. In particular, for evapotranspiration, the observed change trends are not reproduced by any of the investigated 24 RCMs.
UR - http://www.scopus.com/inward/record.url?scp=84882253702&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84882253702&partnerID=8YFLogxK
U2 - 10.1002/jgrd.50224
DO - 10.1002/jgrd.50224
M3 - Article
AN - SCOPUS:84882253702
VL - 118
SP - 2576
EP - 2587
JO - Journal of Geophysical Research. Atmospheres
JF - Journal of Geophysical Research. Atmospheres
SN - 2169-897X
IS - 6
ER -