With climate change, temperature and precipitation is expected to increase in magnitude and variation in Norway, which can increase floods and droughts. With decreases in the use of fossil fuels, supply of energy in Europe, renewable energy will be increasingly important. Therefore, hydropower will become increasingly important. Changes in bio-economy, land use and hydropower along with direct effects of climate change will effect water systems in many ways that are not well understood. In the WatNex project, we will analyse impacts of climate change on hydropower, forestry and agricultural sectors on water systems. We will develop systematic understanding of the sectorial interaction and develop methods to assess changes in climate and water resources. The modelling work and approaches will be developed around two cases in Norway located (Otta and Lærdal river basins). In 2022, the project has worked on Otta river basin in particular. The project team visited the region to learn more about the case and to talk stakeholders from energy, forestry and agricultural asectors. An analysis of the river basin was made to outline the hydropower system and it's regulation permits and practice. We also looked into land use changes and water uses in river Otta. First similations were made with a hydrological model (the CWatM model).
Climate change affects hydrology, water balance and water management in river basins. In the WatNEX project, we will improve quality of input data (climate, land use), sectorial hydrological processes understanding and modelling (energy, forestry, agriculture), and model coupling for an integrated assessment of climate, hydropower, forestry and agriculture at river basin scale. The main objective is to develop methods to assess climate change impacts on water resources considering “in parallel” changes and feedbacks accruing in energy and biomass sectors. We will work on Water-Energy-Food Nexus system understanding in Norway, and assess impacts of climate change and future scenarios considering SSPs and stakeholder information. The modelling work and approaches will be developed around two cases in Norway located in dry regions with high water demand for agriculture and long tradition in irrigation (Otta and Lærdal river basins with annual precipitation about 300 mm). The model work will benefit from forest and agricultural pilot sites in Norway where long term data is available. WatNEX will advance the knowledge on future climate by improved downscaling of precipitation and temperature and estimation of evapotranspiration. We will considerably improve climate impact modelling in river basins, models used in forest hydrology and agrohydrology including irrigation scheduling and river floodplain interactions. The modelling will provide tools to assess climate change effects on sectors separately and jointly in a Climate-WEF coupling. We advance the knowledge on climate change impacts on hydrology, future water supply and demand in river basins, water management modelling considering also cost efficiency (hydro-economic modelling). We will use the results for upscaling, generalization and to provide recommendation for different sectors and for the environment considering climate, biomass and water related policies and development goals.