Influenced by the Gulf stream, the climate in western and central Europe has temperate characteristics, with mild summers and mild winters and a rather even rainfall distribution over the year. Going eastward there is a tendency towards a continental climate with warmer summers and colder winters. Southern Europe has a more Mediterranean climate characterised by warm, dry summers and cool, wet winters with high rainfall intensity. Besides the influence of the Gulf stream, the climate in Europe is determined essentially by the interactions among three pressure centres: the Icelandic Low, the Azores High, and Continental Highs, which predominate in winter, and lows, which generally are confined to summer months (IPCC, 1997). The European climate is highly variable from one place to another due to topographic features that have a significant influence on regional climate (plains, mountains, water bodies).
In the A2b scenario, temperature is rising by 3.5 to 4.5°C in Belgium and northern France, and 5-10 °C (May and June) -and in some parts even 10-15°C- in the southern Spain and Portugal. Broadly speaking, winters are getting wetter and summers are getting drier in the A2b scenario. Rainfall changes shows a strong seasonal pattern and the variation between years in the decade studied is considerable. But most of all, rainfall changes are characterised by a consistent spatial pattern. In the figure below annual rainfall over Europe (2073) is expressed as increase/decrease relative (%) to the base-line climate (MARS database).
The Hadley Centre for Climate Prediction and Research has developed climate scenarios that are based on these emission scenarios. The output of the Hadley Centre’s models for climate change prediction was used to feed the PESERA 1km grid model for erosion prediction. The model selected was the regional climate change model, HADRM3. The HADRM3 files were transferred to grid and then interpolated from a 50x50 to a 1x1 km grid.
Two windows were chosen to run PESERA-RDI_GRID on (see figure window area locations). The first window covers Belgium and small parts of southern UK, northern France, West-Germany, The Netherlands, and Luxembourg. The second window covers the southern part of Spain and Portugal.