Global Terrestrial Evapotranspiration from Optical and Microwave - - PowerPoint PPT Presentation

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Global Terrestrial Evapotranspiration from Optical and Microwave - - PowerPoint PPT Presentation

Jan 02, 2023 13 likes •205 views

Global Terrestrial Evapotranspiration from Optical and Microwave Satellite Observations - Preliminary Results Li Jia RADI-CAS, Beijing, China (jiali@radi.ac.cn) C. Zheng, G.C. Hu, J. Zhou, Z. Li, Y. Cui, J. Lu, K. Wang, Q. Liu, M. Menenti

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Global Terrestrial Evapotranspiration from Optical and Microwave Satellite Observations

  • Preliminary Results

Li Jia RADI-CAS, Beijing, China (jiali@radi.ac.cn)

  • C. Zheng, G.C. Hu, J. Zhou, Z. Li, Y. Cui, J. Lu, K. Wang, Q. Liu, M. Menenti
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SLIDE 2

Outline

  • Background
  • ETMonitor
  • Validation and Intercomparison
  • Application Perspectives
  • Summary
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SLIDE 3

More than 50% of the solar energy absorbed by land surfaces is currently used to evaporate water. Global land evapotranspiration (ET) returns about 60% of annual land precipitation to the atmosphere.

and Surface Water Balance (SWB)

(Figures adapted from Wagner)

  • ET is a term involving Surface Energy Balance (SEB)
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SLIDE 4

Remote Sensing ET Products

ET Product Spatial Res. Temporal Step Spatial Coverage Theory Input RS Data OutPut LandSAF (MSG) ET 3–5 km 30 min, daily Europe, Africa, South America H-TESSEL SVAT scheme

LAI, FVC, Albedo, Downwelling Fluxes, LULC, Snow Cover

ET MODIS ET (MOD16) 1 km 8 days Global P-M

LAI/fPAR, Albedo, LULC ET, LE, Potential ET, Potential LE

ET-VUA (GLEAM) 25 km daily Global P-T + Soil Water Balance

LST, Vegetation Optical Depth, Precipitation, Soil Moisture, Snow Depth, LULC

ET, Interception Loss ET-ITC 5 km monthly Global SEB

LST, NDVI, Albedo, LULC

ET ETMonitor 1 km 250 m 25 m daily Global Regional / Basin scale Multi-Param. (incl. Shuttleworth –Wallace, etc)

LAI, Albedo, Precipitation, Soil Moisture, Snow Cover, LULC ET, E, T, Interception Loss, Potential ET, ET Deficit

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SLIDE 5
  • Involving energy & water balance, and plant physiology processes
  • Combining optical and microwave remote sensing observations

ETMonitor

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SLIDE 6

Global actual ET from ETMonitor

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ETMon

  • nitor
  • r: Validati

tion

180 360 540 720 900 1080 Days since Jan 1, 2009 1 2 3 4 5 6 7 ET (mm/d) EC ETMonitor MOD16 (a) Yingke 180 360 540 720 900 1080 Days since Jan 1, 2009 1 2 3 4 5 6 ET (mm/d) EC ETMonitor MOD16 (b) A'rou 1 2 3 4 ET (mm/d) EC ETMonitor MOD16 (c) Guantan 1 2 3 4 5 6 7 EC (mm/d) 1 2 3 4 5 6 7 Remotely Sensed ET (mm/d) ETMonitor ETMonitor: Linear MOD16 MOD16: Linear (a) Yingke 1 2 3 4 5 6 EC (mm/d) 1 2 3 4 5 6 Remotely Sensed ET (mm/d) ETMonitor ETMonitor: Linear MOD16 MOD16: Linear (b) A'rou 1 2 3 4 Remotely Sensed ET (mm/d) ETMonitor ETMonitor: Linear MOD16 MOD16: Linear (c) Guantan 180 360 540 720 900 1080 Days since Jan 1, 2008 1 2 3 4 5 6 ET (mm/d) EC ETMonitor MOD16 (d) Guantao 1 2 3 4 5 EC (mm/d) 1 2 3 4 5 Remotely Sensed ET (mm/d) ETMonitor ETMonitor: Linear MOD16 MOD16: Linear (d) Guantao 180 360 540 720 900 1080 Days since Jan 1, 2008 1 2 3 4 5 6 ET (mm/d) EC ETMonitor MOD16 (e) Miyun 1 2 3 4 5 EC (mm/d) 1 2 3 4 5 Remotely Sensed ET (mm/d) ETMonitor ETMonitor: Linear MOD16 MOD16: Linear (e) Miyun

Cropland (semi-arid region) Alpine grassland Alpine forest Cropland (semi-humid region) Cropland + orchard (semi-humid region)

2009-2011 2009-2011 2009-2011 2008-2010 2008-2010

China (Hai River Basin, Heihe River Basin)

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SLIDE 8

ETMon

  • nitor
  • r: Validati

tion

1 2 3 4 5 60 120 180 240 300 360 DOY ET (mm/d) EC ETMonitor y = 0.8291x - 0.0331 R2 = 0.7614 1 2 3 4 5 1 2 3 4 5 EC ET (mm/d) ETMonitor (mm/d) 1 2 3 4 5 60 120 180 240 300 360 DOY ET (mm/d) EC ETMonitor y = 1.1038x - 0.0625 R2 = 0.7684 1 2 3 4 5 1 2 3 4 5 EC ET (mm/d) ETMonitor (mm/d)

Alpine grassland (Maqu) Alpine forest (Linzhi)

1 2 3 4 5 60 120 180 240 300 360 DOY ET (mm/d) EC ETMonitor y = 0.4011x + 0.6008 R2 = 0.2365 1 2 3 4 5 1 2 3 4 5 EC ET (mm/d) ETMonitor (mm/d)

Alpine grassland - wetland (MS3478)

y = 1.1034x - 18.464 R2 = 0.7451 60 70 80 90 100 110 60 70 80 90 100 110 EC ET(mm/month) ETMonitor (mm/month)

Rain forest (Xishuangbanna, monthly)

2013 2013 2013 2013

China (Tibetan Plateau, Yun-Gui Plateau)

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ETMon

  • nitor
  • r: Validati

tion

Europe & Africa

1 2 3 4 5 60 120 180 240 300 360 Days since Jan 1, 2012 ET (mm/d) EC ETMonitor MSG

y = 1.06x - 0.28 R2 = 0.95 RMSE = 0.32 mm/d 1 2 3 4 1 2 3 4 Observed ET (mm/d) ET by ETMonitor (mm/d)

1 2 3 4 60 120 180 240 300 360 Days since Jan 1, 2012 ET (mm/d) EC ETMonitor MSG

y = 0.85x + 0.36 R2 = 0.74 RMSE = 0.46 mm/d 1 2 3 4 1 2 3 4 Observed ET (mm/d) ET by ETMonitor (mm/d)

Grassland (Cabauw) Forest (Loobos) Savanna (ZA-Kru)

1 2 3 4 5 60 120 180 240 300 360 DOY ET (mm/d) EC ETMonitor MOD16 y = 0.8461x + 0.0493 R2 = 0.7648 1 2 3 4 5 1 2 3 4 5 EC ET (mm/d) ETMonitor (mm/d)

Forest (CZ-BK1)

1 2 3 4 5 60 120 180 240 300 360 DOY ET (mm/d) EC ETMonitor MOD16 y = 0.5664x + 1.1054 R2 = 0.394 1 2 3 4 5 1 2 3 4 5 EC ET (mm/d) ETMonitor (mm/d)

Savanna (ES-LMa)

1 2 3 4 60 120 180 240 300 360 DOY ET (mm/d) EC ETMonitor MOD16 y = 0.7528x - 0.2184 R2 = 0.7138 1 2 3 4 1 2 3 4 EC ET (mm/d) ETMonitor (mm/d)

Grassland (IE-Dri)

2012 2010 2010 2010 2012

y = 0.481x + 0.7543 R2 = 0.4537 1 2 3 4 5 1 2 3 4 5 EC ET (mm/d) ETMonitor (mm/d) 1 2 3 4 5 30 60 90 120 150 180 210 240 270 DOY ET (mm/d) EC ETMonitor

2010

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SLIDE 10

Inter ercomparison

  • n with

th RS E ET p product cts

ETMonitor (1km, daily) MOD16 (1km, 8-day) SEBS (ITC) (0.05 °, monthly) mm/yr

Global ET, 2010 actual total

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SLIDE 11

Inter ercomparison

  • n with

th RS E ET p product cts

ETMonitor MSG MOD16 SEBS

Annual total actual ET in Africa in 2010

ET from ETMonitor is more closely related to MSG ET from geostationary satellite

  • bservation

mm/yr

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SLIDE 12

LAI and S SM deter ermine t e the E e ET patter ern

ETMonitor, July 2010 LAI DOY=193

7

SM ASCAT, DOY=193

1

mm/yr

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DMC based ET (daily, 25m), Flevoland, NL

May, 2013 June, 2013 July, 2013 Aug, 2013 Sept, 2013

2 4 6 8 10 12 14 16 20 40 60 80 100 120 140 160 ET (mm/month) Frequency (%) May Jun. Jul. Aug. Sep.

ETMonitor: High Resolution

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SLIDE 14

1 2 3 4 5 6 120 240 360 480 600 720 Days since Jan 1, 2012 ET (mm/d) EC ETMonitor y = 1.20x - 0.58 R2 = 0.75 RMSE = 0.55 mm/d 1 2 3 4 5 6 1 2 3 4 5 6 Observed ET (mm/d) ET by ETMonitor (mm/d) 1 2 3 4 5 6 120 240 360 480 600 720 Days since Jan 1, 2012 ET (mm/d) EC ETMonitor y = 0.99x - 0.02 R2 = 0.45 RMSE = 0.74 mm/d 1 2 3 4 5 6 1 2 3 4 5 6 Observed ET (mm/d) ET by ETMonitor (mm/d)

Cabauw (grassland) 2012–2013 (daily) Loobos (Forest) 2012–2013 (daily)

DMC based ET (daily, 25m), Validation

ETMonitor: High Resolution

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SLIDE 15

Drought Monitoring (China, 2011):

  • Yangtze River Basin
  • Inner-Mongolia

ETMonitor: Water Demand and Deficit

ET Deficit (ETpot – ETact)

YRB

Application Perspectives

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SLIDE 16

ETMonitor: Water Demand and Deficit Application Perspectives

P - ET, 2010

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Summary

  • Both vegetation and sol moisture patterns

determine the ET distribution.

  • Accuracy and spatial resolution of soil moisture are

critical for ET estimate at corresponding scales.

  • Sentinel 2 will contribute to ET estimate at higher

resolution both in space and in time.

  • Better ET product will benefit to water resource

management in terms of drought monitoring, water productivity, etc.

  • Global Validation is needed
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SLIDE 18

References

  • Hu G.C. and L. Jia, 2015, Monitoring of Evapotranspiration in a Semi-Arid Inland River

Basin by Combining Microwave and Optical Remote Sensing Observations, Remote Sensing, 7(3), 3056-3087; doi:10.3390/rs70303056.

  • Hu G.C., L. Jia*, Menenti M. 2015, Comparison of MOD16 and LSA-SAF MSG

evapotranspiration products over Europe for 2011. Remote Sensing of Environment, 156, 510–526, doi:10.1016/j.rse.2014.10.017.

  • Cui Y.K., L. Jia*, G.C. Hu, and J. Zhou, 2015, Mapping of Interception Loss of Vegetation

in the Heihe River Basin of China Using Remote Sensing Observations, IEEE Geoscience and Remote Sensing Letters (IEEE GRSL), 12(1), 23 – 27; doi:10.1109/LGRS.2014.2324635.

  • Cui Y.K., L. Jia*, 2014, A Modified Gash Model for Estimating Rainfall Interception Loss
  • f Forest Using Remote Sensing Observations at Regional Scale, Water, 2014, 6(4), 993-

1012; doi:10.3390/w60

  • Cui Y.K., L. Jia*, 2015, Regional Land Surface Evapotranspiration from ETMonitor+ by

Assimilating Surface Soil Moisture Data, manuscript to be submitted to Agriculture & Forest Meteorology.

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Thank you for your attention !

Li Jia Team Earth Observation for Water Cycle State Key Laboratory of Remote Sensing Institute of Remote Sensing and Digital Earth (RADI), Chinese Academy of Sciences jiali@radi.ac.cn http://eo-water.radi.ac.cn/en (under construction)