Climate change and runoff from agricultural catchments in Norway

Purpose - The purpose of this paper is to investigate the effects of extreme weather conditions on runoff, nutrient, and soil loss from agriculture-dominated catchments at different locations in Norway. Design/methodology/approach - Four catchments have been selected to study the potential effects of climate change on runoff and nutrient loss. The catchments are part of the Agricultural Environmental Monitoring Programme in Norway (JOVA) and represent different climatological conditions, agricultural production systems/practices, and soil types. Different characteristics were calculated on the basis of existing measurements and evaluated with respect to climate change. Findings - In four selected catchments, climate change is predicted to lead to an increase in runoff. Under similar land use and tillage methods, this will most likely lead to an increase in nutrient and soil loss. Milder winters as a consequence of climate change might lead to extreme runoff conditions and severe erosion, caused by a combination of frozen soil, snowmelt, and intense rainfall. Existing large diurnal variations in discharge have to be taken into consideration in the future design of hydrotechnical implementations. Information about the potential effects of climate change on runoff generation, the magnitude of the different hydrological flow paths, and their potential effects on nutrient and soil loss processes is necessary in choosing the right mitigation measures. Originality/value - Long time series on runoff and water quality (such as those collected in small agriculture-dominated catchments as part of the Agricultural Environmental Monitoring Programme in Norway (JOVA)) are rare, but indispensable in evaluating the potential effects of climate change on nutrient and soil loss.