Research Institute For Geo-Hydrological Protection (CNR-IRPI) Perugia .

http://hydrology.irpi.cnr.it18 December 2020Luca Brocca and the IRPI Hydrology GroupResearch Institute for Geo-Hydrological Protection (CNR-IRPI)Perugia, Italy

We, as human beings, aremodifying the water cycle Irrigation is the major waterconsumer of our planet (70%),over Mediterranean 75% 2 billion people affected bywater stress - a number thatwill only increase withpopulation growth, continuedeconomic development andclimate changing Global blue water availability:5’000-9’000 km³/yearGlobal water consumption:3500-5000 km³/yearwww.irpi.cnr.itAbbott et al. (2019 Nature -yIRRIGATION IMPACT ON THE WATER CYCLE2

IRRIGATION IMPACT ON THE WATER CYCLE”We find that in up to 35% of currently rain-fed croplands, irrigationcould be expanded as an adaptation strategy to climate changewithout negative environmental externalities on freshwaterresources.”PNAS, Nov 9, 2020; https://doi.org/10.1073/pnas.2017796117”Here we provide observational and model evidence that expandingirrigation has dampened historical anthropogenic warming duringhot days, with particularly strong effects over South Asia.”Nat Communication, Jan 15, 2020; https://doi.org/10.1038/s41467-019-14075-4“heat stress projections in regions dominated by semiarid/monsoon climates that do not include the role of irrigationoverestimate the benefits of irrigation on dry heat stress andunderestimate the risks.”Nat Geoscience, Oct 26, 2020; .cnr.itAll these studies rely on the global map of irrigationareas dated 2005 (areas equipped for irrigation) andsimulated data3

What is soil moisture?Soil moisture is a keyvariable of the climatesystem.Soil moisture generallyrefers to the amount ofwater stored in theunsaturated soil zone.www.irpi.cnr.itSeneviratne et al. (2010 4CAN WE USE SOIL MOISTURE FOR IRRIGATION QUANTIFICATION?4

15 YEARS OF RESEARCH ON SOIL MOISTURE!!!20052007JoH paper2010HESS paper2014JGR paper2018JAG paperIrrigation from spaceSoil moisturemonitoringwith in situand remotesensingUnderstandingthe spatialtemporalvariability of soilmoisture atdifferent spatialscalesAssimilation of insitu and remotesensing soilmoisturemeasurements g rainfall from thebottom up: using soil moistureobservations for measuringrainfall (SM2RAIN)5

SOIL MOISTURE MONITORINGREMOTE SENSING(AMSR-E, AMSR2, SAR, Scatterometers,ASCAT, SMOS, SMAP, Sentinel-1, .)HYDROLOGICALWATER BALANCELAND SURFACEMODELLINGwww.irpi.cnr.itIN SITU(TDR, FDR, Gravimetric,Geophysical methods,COSMOS, GPS)6

SOIL MOISTURE MONITORINGLaboratoryExperimental catchmentsTDR spot bes7

REMOTE SENSING OF SOIL MOISTURESMAP:Soil MoistureActive andPassive missionwww.irpi.cnr.it8

A constellation of satellitesensors for measuring soilmoisture is available High temporal and spatialresolution only recently: Sentinel-1 CYGNSS future missions: FSSCat L-band SAR HYDROTERRA (EE10)www.irpi.cnr.itBrocca et al. (2017 WATER)https://doi.org/10.3390/w9020140REMOTE SENSING OF SOIL MOISTURE9

Sentinel-1 Soil Moisturewww.irpi.cnr.itBauer-Marschallinger et al. (2018 IEEE TGRS)https://doi.org/10.1109/TGRS.2018.2858004HIGH RESOLUTION SOIL MOISTURE FROM SENTINEL-110

Field scale soilmoisture monitoringfrom spacewww.irpi.cnr.itBazzi et al. (2020 HIGH RESOLUTION SOIL MOISTURE FROM SENTINEL-111

Brocca et al. (2011 ATION OF SATELLITE SOIL MOISTURE PRODUCTSwww.irpi.cnr.it12

.5SWI-CDFAverageR-values 0.850AMSRE-NASA0.51AMSRE-LPRMRSE)Brocca et al. IDATION OF SATELLITE SOIL MOISTURE A1Correlation between satelliteproducts and ground dataFR-PRG-obsFR-VOB-modAMSRE-PRI13

ITALYwww.irpi.cnr.itBrocca et al. (2011 ATION OF SATELLITE SOIL MOISTURE PRODUCTS14

1’800’000 measurements !!!www.irpi.cnr.itPaulik et al. (2014 ATION OF SATELLITE SOIL MOISTURE PRODUCTS15

OPERATIONAL SOIL MOISTURE PRODUCTS (EUMETSAT H SAF)Large-scale surface soil moisture observed byradar scatterometer (ASCAT)Resolution 25 km (Sampling 12.5 km)Daily coverage, 0-5 cm2007 – ongoingVolumetric soil moisture (roots region) by assimilation thelarge scale soil moisture product in NWP model (IFS-ECMWF)Resolution 16 kmDaily coverage, 4 soil layer1992 – ongoing0-7 cm16-12-2020 02:208-29 cm30-100 cm15-12-2020 14:10www.irpi.cnr.it16

OPERATIONAL SOIL MOISTURE PRODUCTS (COPERNICUS)COPERNICUS C3S SOIL MOISTURE1978 to present, 1/10-day, 0.25-degreeSOIL WATER INDEX: 2007 to present, 1/10-day, 0.1-degreeSURFACE SOIL MOISTURE: 2014 to present, 5-day, 1 kmwww.irpi.cnr.it17

SM2RAIN: RAINFALL ESTIMATION FROM SOIL MOISTURESoil moisturerelative soil moistureprecipitationdrainageZ*ds(t)/dt p(t)-r(t)-e(t)-g(t)soil watercapacity soil depth X porosityr(t):surfacerunoffPrecipitationsurface runoffg(t):drainage deep percolation subsurface runoffevapotranspirationDuring rainfall, surface runoff and evapotranspiration are assumed tobe negligible (demonstrated in Brocca et al., 2015 JHH):g(t) as(t)br(t) 0e(t) 0bp(t) Z*ds(t)/dt as(t)www.irpi.cnr.itp(t):rainfallBrocca et al. (2015 vapotranspiration18

SM2RAIN is a new“bottom-up” approach(Brocca et al., 2014 JGR)for estimating theACCUMULATEDRAINFALL from satellite(and in situ) soilmoisture observationswww.irpi.cnr.itBrocca et al. (2014 JGR)https://doi.org/10.1002/2014JD021489SM2RAIN: RAINFALL ESTIMATION FROM SOIL MOISTURE19

SM2RAIN-ASCATSM2RAIN: GLOBAL RAINFALL PRODUCTSBrocca et al. (2019 ESSD)https://doi.org/10.5194/essd-11-1583-2019Data Period: 2007-2019Spatial\Temporal Resolution: 12.5 km\1-daywww.irpi.cnr.itFreely available @ Zenodohttps://doi.org/10.5281/zenodo.259121420

WE HAVE A PROBLEM WITH SM2RAIN Reviewer comment in one of our SM2RAIN paperThrough soil moisture you don’t see rainfall, but the total amount ofwater entering into the soil.You are getting WRONG results over irrigated areasCAN WE USE SOIL MOISTURE FORESTIMATING IRRIGATION WATER VOLUMES?(The missing variable in the WATER CYCLE)www.irpi.cnr.it21

IRRIGATION WATER FROM SOIL MOISTURE OBSERVATIONSWe apply SM2RAIN to synthetic soilmoisture to obtain SM2RAIN-derivedrainfall irrigation (magenta line),compared with observed rainfall (greenline).We subtract observed rainfall (greenline) from SM2RAIN-derivedrainfall irrigation (magenta line) toobtain irrigation (black line), comparedwith observed irrigation (grey area)www.irpi.cnr.itBrocca et al. (2018 JAG)https://doi.org/10.1016/j.jag.2018.08.023We simulate soil moisture without (blueline) and with (red line) irrigation22

Filippucci et al. (2020 02Rainfall and irrigation[mm/day]IRRIGATION WATER FROM IN SITU SOIL MOISTURE OBSERVATIONSEmilia Romagna (Italy)www.irpi.cnr.it23

REMOTE SENSING OF IRRIGATION FROM SOIL MOISTURE OBSERVATIONSAuthorsYearDoiLocationBrocca et and et al.201910.1016/j.rse.2019.111226IranZaussinger et al.201910.5194/hess-23-897-2019United StatesFilippucci et al.202010.1016/j.advwatres.2019.103502ItalyDari et al.202010.3390/rs12162593SpainZohaib & fia-Rosenzweig et al.201910.1029/2019MS001797United Stateswww.irpi.cnr.it24

SPACE-IRRWe have won the “BayWa Smart Farming Challenge” at2018 COPERNICUS MASTER for the idea “SPACE-IRR –How Much Water for Irrigation?”Simulated SM withIRRIGATIONRainfall andirrigation[mm/day]Soilmoisture [-]Simulated SM withoutIRRIGATIONSentinel-1 (S1) seems to be able to see the irrigation signal at small spatial scalewww.irpi.cnr.it25

IRRIGATION PROJECTThe IRRIGATION ESA project aimsto explore, develop and validateadvanced EO-based algorithms andtechniques for irrigation mapping,quantification and detection ofseasonal timing of irrigation fromfield to regional/global scale.www.irpi.cnr.it26

IRRIGATION PROJECTGERMANYSPAINSOUTH AFRICAAUSTRALIAITALYFRANCEwww.irpi.cnr.it27

Dari et al. (2020 RS)https://doi.org/10.3390/rs12162593IRRIGATION FIRST RESULTSwww.irpi.cnr.it28

.com/esa/events/9394033/videos/213543876Zappa et al. (2020 ESA EO4WATER)IRRIGATION FIRST RESULTS29

IRRIGATION FIRST RESULTS𝑥 𝑥 𝐾 𝑦 ℎ 𝑥 Sentinel-1backscatter (σ0)VV- VHwww.irpi.cnr.it(DOI: 10.1175/2009JHM1116.1) Water Cloud Model (WCM)(DOI:10.1029/RS013i002p00357)Modanesi et al. (EO4WATER, 2020)https://www.youtube.com/watch?v o0fRDBGedJAData AssimilationNoah MP v.3.6with/without irrigation30

KEEP HOME MESSAGE Irrigation is (very likely) the mostimportant unknown in the watercycle High resolution hydrologicalmodelling (DTE Hydrology) cannotbe separated from the knowledgeof human intervention on the watercycle (including irrigation) Remote sensing has potential toprovide information on irrigation(where, when and how much)www.irpi.cnr.itADDITIONAL p://hydrology.irpi.cnr.it@Hydrology IRPIHow much water is usedfor irrigation?31

sensors for measuring soil moisture is available High temporal and spatial resolution only recently: . FSSCat L-band SAR HYDROTERRA (EE10) REMOTE SENSING OF SOIL MOISTURE R) 0. www.irpi.cnr.it 10 Sentinel-ure r-er) 4 HIGH RESOLUTION SOIL MOISTURE FROM SENTINEL-1. www.irpi.cnr.it 11 HIGH . techniques for irrigation mapping, quantification .