Modelling Catchment‐Scale Responses to Climate Change

Abstract

The focus of the Euro-limpacs project was on responses of aquatic ecosystems (rivers, lakes and wetlands) to climate change, but these responses cannot be fully understood or predicted without considering the connections to other earth systems. Rivers, lakes and wetlands are connected to each other and to other water bodies such as groundwater and estuarine and coastal waters. Most of the water in these aquatic systems has passed through the terrestrial environment at some stage. A catchment-scale approach that considers these different environments is thus essential for predicting how European aquatic ecosystems might respond to climate change. Typically, measurements of the aquatic and terrestrial environments and experimental manipulations are done in small ( 1000 km2), as in the EU Water Framework Directive, in which the River Basins are all large catchments. Furthermore, projections of future climates made by the models of atmospheric and oceanic circulation (General Circulation Models, GCMs) are produced at a coarse scale greater in size than many catchments. Models can help fill the gaps between the mismatch of scales between scientific measurement, management and climate projections. The complexity of the interactions between all these aquatic and terrestrial systems also necessitated a modelling approach: individual experiments and manipulations alone cannot consider this complexity or integrate the different processes. Modelling catchment responses to climate change is a very demanding undertaking, requiring a number of tasks that are themselves very challenging. Firstly, in order to make predictions of the effects of climate change, it is necessary