Drought and soil moisture in context of

climate change : results and

operational applications of ClimSec

project in France

Patrick Josse1, Jean-Michel Soubeyroux1,

Eric Martin2, Jean-Philippe Vidal1,3

1 : Météo-France, Direction de la Climatologie et des Services Climatiques

2 : CNRM/GAME, Météo-France/CNRS

3 : IRSTEA, Lyon

Our Common Future Under Climate Change

International Scientific Conference 7-10 JULY

2015 Paris, France

Contents

ClimSec project

Overview of drought patterns

– Drought indices

– Propagation through the hydrological cycle

– Events analysis

Evolution with climate change

– Current trends

– Droughts evolution in future climates

From science knowledge to climate services

– DRIAS web site

ClimSec project

3-year project: “Impact of climate change on drought and soil moisture in France” , funded by Fondation MAIF

Motivated by damages following 2003 drought and the question

whether such events will be more frequent in the future

Focus on the reanalysis of drought events for characterizing present

climate and climatic projections for future evolutions

Operational application on water resources monitoring and drought

anticipation

Vidal et al (2010), Multilevel and multiscale drought reanalysis over France with the Safran-Isba-Modcou hydrometeorological suite.

Hydrology and Earth System Sciences, 14(3), 459-478. DOI : 10.5194/hess-14-459-2010 WMO Norbert Gerbier Price 2010

Safran-Isba-Modcou (SIM)

Safran

atmospheric

analysis system

Optimal Interpolation

of ERA-40 + ground

observations

Gridded rainfall, snowfall,

temperature, humidity, wind speed,

visible, infrared radiation (8km, hourly)

Isba

land surface

scheme

Computation of water

and energy budgets

with soil and

vegetation databases (ECOCLIMAP)

Evapotranspiration, soil moisture,

snow cover, drainage, runoff, etc. (8km,

5 min)

Drainage and runoff

Modcou

hydrogeological

model

Flow routing,

multilayer aquifers

Flow (3-hourly) and water table levels

(1-8km)

wiltfc

wilt

ww

wwSWI

– w : water content

– wwilt : wilting point

– wfc : field capacity

50-year SIM

hydrometeorological reanalysis

(From 1958 to 2008)

Drought indices

Drought : abnormal water deficit in one (or more) part of the land

surface hydrological cycle

Choice of relevant drought indices depends on the socio-economic

activity domain No universal drought index

SIM: consistent computation of variables within the hydrological cycle

Standardized index approach

– Standardized Precipitation Index (SPI) → 8km grid

– Standardized Soil Wetness Index (SSWI) → 8km grid

– Standardized Flow Index (SFI) → >900 hydrometric stations

Variable Drought type

Safran Precipitation Meteorological

Isba Soil Wetness Index Agricultural

Modcou River flow Hydrological

Overview of dry periods

Area affected by drought (% of France area), 3-month indices, threshold 5%

Autumn 1978 1976 1989-1990 2003

SPI3

SSWI3

SFI3

SP

I3

020

40

60

80

100

SS

WI3

020

40

60

80

100

020

40

60

80

100

SF

I3

1960 1970 1980 1990 2000

From indices to events – Local scale

Grid cell located near Toulouse (south-west), SSWI3

-2.0

-1.0

0.0

0.5

1.0

1.5

SS

WI3

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Duration

Severity

Magnitude

Threshold

P = 5%

Starting date

Peak date

End date

Drought events analysis

Mean

duration

(months)

SPI3 SSWI3

Mean area (% of France)

National event identification according to drought pattern in both space and

time : event envelop, spatial and temporal contiguity

Spatio-temporal characteristics

1. [Duration, severity, magnitude] combined with area

Observed trends on agricultural droughts

Monitoring of mean annual drought area in France as climate change index

Mea

n a

rea (

% o

f F

ran

ce)

Drought mean annual area

with SSWI (1 month) index

1961-1990 mean decadal mean

8 of the last 10 years with drought area

above the 1961-1990 mean Increase of drought area since

1990th

Drought evolutions with climate change

Mean area (%

of France)

A good confidence for a strong increase of agricultural drought along the

21st century

Vidal et al.(2012), Evolution of spatio-temporal drought characteristics: validation, projections and effect of adaptation scenarios.

Hydrology and Earth System Sciences Discussions, 9(2), 1619-1670. DOI : 10.5194/hessd-9-1619-2012

Climate services on Drias website

Drias Web site aims to

provide regionalized

climate projections

computed by several

French laboratories

involved in climate

modeling (IPSL,

CERFACS, CNRM-

GAME).

An appropriation in

three steps : Education

Space, Discover Space

and Products Space

Availability of ClimSec

projections to help

adaptation on water

resources domain

A consistent approach by hydrometeorology modeling for monitoring

drought and characterization of drought events in France

All spatial and temporal characteristics of drought events are

expected to dramatically increase over the century, with stronger

changes for agricultural droughts, already visible on trends.

Development of climate services for water resources to help

adaptation policies

Conclusions

Thank you for your attention

Contact:

Patrick.josse@meteo.fr

1988-1990 SSWI3 drought (envelop P=20%)