EEA-JRC-WHO 2008 Indicator report on CC Water quantity indicators Luc Feyen Presented by Carlo Lavalle Land Management and Natural Hazards Unit Institute for Environment and Sustainable Development, Joint Research Centre, European Commission, Italy Advisory group meeting Copenhagen, 23 April 2008

Water quantity indicators Sub-chapter 5.7 Indicators (Lead author) April 2008 Water quantity river flow, floods and drought Coordinator: Luc Feyen EEA Contact: Peter Kristensen 5.7.1 Category introduction JRC (Feyen) Draft 6 5.7.2 River flow 5.7.3 River floods 5.7.4 River flow drought Textbox Groundwater EEA (Kristensen)

5.7.1 Category introduction important to stress that several pressures on water, not only CC very difficult to detect changes, and link to CC, especially for extreme events projections are uncertain links with other indicators (precipitation, snow)

Water quantity indicators Issue Indicator(s) Past trend Projec- tions Spatial coverage River flow Change in annual runoff during the 20th century Changes in annual and seasonal runoff between 1961-1990 and 2071-2100 X European River floods Recurrence of flood events in Europe for the period 1998-2005 Relative change in 100-year return level of river discharge River flow droughts Change in drought severity in Europe between 1962-1990 Change in drought severity in France between 1960-2000 Relative change in mean annual and summer minimum 7-day runoff + France Groundwater/ aquifer recharge Text box

5.7.2 River flow 5.7.2 observed trend: now European map included Relative change in runoff (%) during the twentieth century. Period 1971-1998 compared to 1900-1970. From Milly et al., Nature, 2005.

5.7.2 River flow 5.7.2 projected trend Relative change in seasonal and annual runoff between 1961-1990 compared to 2071-2100 (SRES A2). From Dankers and Feyen, 2008.

5.7.2 River flow 5.7.2 projected trend This figure has been added to show better the projected changes in seasonality of flow in a few catchments. Change in daily average river flow between 2071-2100 (blue line) and 1961-1990 (black line). Simulations with LISFLOOD driven by HIRHAM – HadAM3H/ HadCM3 and IPCC SRES scenario A2 (Dankers and Feyen, 2008).

5.7.3 River floods 5.7.3 observed trend Recurrence of flood events in Europe for the period 1998-2005 (EEA, 2006). The figure on the left does not give any information about a trend. The figure on the right (used in the previous report) shows a clear trend in the number of events, but this is mainly caused by better reporting. If the figure on the right is preferred, it should be made clear that the rise has little to do with climate change, but increased damages have caused more attention to floods, and better reporting has led to an increase of reported events.

5.7.3 River floods 5.7.3 projected trend Relative change in 100-year return level of river discharge between scenario (2071-2100, SRES A2) and control period (1961-1990). From Dankers and Feyen, 2008.

5.7.4 River flow droughts 5.7.4 observed trend It was suggested to combine the information from different studies into one figure. However, the authors of the different studies did not prefer this option due to some difference in analysis and time period used to derived indicators. Therefore, 2 figures are presented which both show changes in the drought severity. change in drought severity between 1962-1990 change in drought severity in France between 1960-2000

5.7.4 River flow droughts 5.7.4 projected trend Relative change in mean annual and summer minimum 7-day river flow between scenario (2071-2100, SRES A2) and control period (1961-1990). From Feyen and Dankers, 2008.

Water quantity - conclusions introduction captures main issues 3 indicators (river flow, floods, droughts) well developed 1 textbox on groundwater