1. ORCHIDEE-Dev : January 8th, 2013 Theme #1 Water cycle, river flows, water quality and interactions with biosphere under future climate Réservoir souterrain Réservoir fleuve 10 0 m 10 1 m 10 5 m D Rs E Soil : Choisnel vs. CWRR Temperature, permafrost River routing, wetlands, biogeochemical cycles ET and climate interactions

2. - Global effect of irrigation and its impact on the onset of the Indian summer monsoon (Guimberteau & al., 2012, Clim. Dyn.) => when irrigation is activated : - delayed monsoon onset + weakened monsoon - summer precipitation increase (decrease) over western (eastern) Mississippi - A comprehensive approach to analyze discrepancies between land surface models and in-situ measurements: a case study over the US and Illinois with SECHIBA forced by NLDAS (Guimberteau & al., 2012, HESS) => improvement of simulated soil moisture through sensitivity tests of vegetation parameters + use of a different evapotranspiration computation and precipitation input - Discharge simulation in the sub-basins of the Amazon using ORCHIDEE forced by new datasets (Guimberteau & al., 2012, HESS) => improvement of simulated discharges with new data sets of daily precipitation forcing & floodplains/swamps spatial coverage - Future changes in precipitation and impacts on extreme streamflow over Amazonian sub-basins (Guimberteau & al., sub. to ERL) => see next slide Matthieu GUIMBERTEAU Post-doc IPSL-SISYPHE-LSCE Work on ORCHIDEE: since 2006 Main research topics: hydrology, water cycle, irrigation, streamflow, LSM assessment, Amazonian hydrology Mail: matthieu.guimberteau@upmc.frmatthieu.guimberteau@upmc.fr Web page: http://www.sisyphe.upmc.fr/~guimberteau/ Past researches Present research: Amazon River basin - 2lay./11lay. hydrology comparison and assessment - Improvement of hydrology: soil & rooting depths, soil hydraulic properties - Soil water infiltration according to the offline precipitation spread over the time-step - Impact of LUC and Climate Change on hydrolog In the framework of the AMAZALERT project

3. Future changes in precipitation and impacts on extreme streamflow over Amazonian sub-basins (Guimberteau & al., sub. to ERL) Construction of future climate forcings (delta downscaling method): for each of the 8 AR4 GCMs => 20yr-climatology for each variable => computation of anomalies between future and present-time => addition of anomalies on each 6h NCC time-step (NCC previously corrected by daily precipitation dataset) ORCHIDEE forced by 8 different future climate forcings => comparison with present-time simulation Mean relative change (%) of the low flows for 16 stations (for each of the eight simulations, differences performed between each future year and the present-time seasonality) Result for 2046-2065 under SRESA1B scenario Number of GCMs out of eight that project a JJA precipitation increase Southern sub-basins (with low runoff coefficients (R/P)) will become more responsive to precipitation change than the western sub-basins (with high runoff coefficients) Western and north-western sub-basins: more responsive to evaporation change