Climate effects INCA-P New Papers PERSiST

Climate or land use change – which will have the biggest effect on water quality?

Agricultural intensification for fossil fuel substitution (the land-based bioeconomy) has the potential to affect both food security and water quality. Csilla Farkas and colleagues recently published a study on the possible consequences for surface water quality of future changes in land use due to a greater reliance on the bioeconomy in a time of rapid climate change.

They hypothesized that greater agricultural biomass production would increase the risk for soil loss and enhance suspended sediment yields in streams and that these effects would be exacerbated under a changing climate.

Using hydrological and bias adjusted climate models, the authors compared the effect of seven land use pathways on discharge and sediment transport relative to a baseline scenario under present and future climate conditions for a small headwater stream representative for cereal production areas in southeast Norway. Using PERSiST and INCA-P, they showed that land use change had a greater influence on both future water discharge and sediment losses than possible future climate change. Climate-related changes showed strong seasonal effects. Of the modelled land use (Nordic Bioeconomy) scenarios, a sustainable pathway manifested the least occurrence of extreme flood and sediment loss events under future climate; whereas a pathway based on national self-sufficiency had the highest occurrence of such extreme events.

The study findings highlight the need to place careful attention on land use and soil management in areas likely to be subject to agricultural intensification for bioeconomy purposes and the increasing need to implement environmental mitigation measures to maintain freshwater quality.