Evapotranspiration Rates, their Changes, and Change Implications for Water Availability across Different Land-Use Areas
Jaramillo, Fernando; Destouni, Georgia
Department of Physical Geography and Quaternary Geology/ Stockholm University, SWEDEN
Changes in land-use affect hydrological flow partitioning and evapotranspiration at the land surface, and under some conditions more so than global climatic change alone (Destouni et al., 2013). Research on vapor emission rates from different characteristic land covers can shed light on the conditions for land-use being a dominant driver of such hydrological changes. We here investigate recent MODIS Evapotranspiration (Mu et al., 2011), climatic (Mitchell and Jones, 2005), land-use (Friedl et al., 2002) and hydrological data (Swedish Meteorological and Hydrological Institute, 2010) across the whole of Sweden, finding that, in this region, agricultural land-use with herbaceous crops yields higher vapor emissions by evapotranspiration than typical forest and wetland areas. These results support other recent findings regarding evapotranspiration effects of non-irrigated agriculture, and evapotranspiration comparisons across different land-use areas (Van der Velde, 2013; Jaramillo et al., 2013; Destouni et al., 2013). If these results are specific for Sweden, or the whole Scandinavian region, they imply that simple cross-regional spatial extrapolation of vapor emissions for key land covers may be misleading and should be avoided. If the found evapotranspiration relations are not just restricted to this region, they imply that agricultural expansion (non-irrigated as well as irrigated) for meeting increasing human demands for food and/or biofuel may generally decrease water resource availability in the landscape across different regions and scales.
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