summer colloquium on the physics of weather and climate adaptation of a hydrological model to...

Summer Colloquium on the Physics of Weather and Climate

ADAPTATION OF A HYDROLOGICAL MODEL TO ROMANIAN PLAIN

MARS (Monitoring Agriculture with Remote Sensing) project

cooperation with CIRAD France

Elena SAVIN, Gheorghe STANCALIE, Corina ALECU National Institute of Meteorology and Hydrology Bucharest


ROMANIA

- geographical position

East Europe

- climate: temperate:

annual mean temperature 10 C

precipitation (400 - 700 mm/year)

- cultivated surface : 20 000 ha


Demand from: minister and trade

- product estimation for cultivated

areas for wheat and maize

Solution: adaptation of a simple water balance model - BIPODE

Possibilities - many models

Limitations - available data

steps: adaptation for station

surface yield estimation


INPUT DATA OUTPUT DATA

meteo : mean daily temperature (C) maximum evapotraspiration (mm) relative humidity (%) real evapotraspiration (mm) sun shine duration (hours) ETR/ETM ratio (%) wind speed (m/s) water amount for irrigation

plant: type (white, maize) phenological phases duration sowing date crop coefficient root growing rate (cm/day)

soil: type ADAPTATION: field capacity at 1 m - crop coefficient water content at sowing date at 1 m - root growing rate - ETP daily values


Algorithm used by BIPODE 1. Ru = 0 if P<Pth

Ru = Kr *Pth ifP>Pth

2. Peff = P-Ru

3. Dr = 0 if Peff+Wa z-1<AWC

Dr = AWC - (Peff+AWC z-1)

SOIL reservoir1m 4,5,9

DR 3

RU, 1

ETR, 8

ETM, 7

ETP, KcP

Kr, Pth

AWC

5 AWCrZ, RGR

Peff, 2

HR, 6

input data

output data

4. WAz = Peff - Dr + WAz-1 on entire profile

5. Knowing the day (z) and the root growth rate (RGR) AWCr and War were determined

6. HR = Awrz/AWCr

7. ETM = Kc*ETP

8. ETR = f(ETM,HR)

9. Awz = Peff - Dr - ETR + Awz-1


Crop coeficient - maize

0

0,2

0,4

0,6

0,8

1

1,2

1,4

0 20 40 60 80 100 120 140 160 180

Days

Vegetativ phase

FloweringMaturity

Crop coeficient - wheat

0

0,2

0,4

0,6

0,8

1

1,2

1,4

0 50 100 150 200

Days

Germination Tallage Montaison

Flowering Maturity

CROP COEFICIENTS

Phenological phases - mean from 170 data sets for wheat and 101 for maize


The best correlation yield - IR (obtained from 60 data sets - wheat 30 data sets - maize)

IR=(ETR/ETM)flowering*(ETR)vegetative period

Maize

0

2000

4000

6000

8000

10000

12000

14000

0 50 100 150 200 250 300 350 400

IR=(ETR/ETM)flowering*(ETR)vegetative period

Yie

ld (

Kg

/ha

)

Yild=23.3 * IR + 2960

r2=0.61Wheat

0

1000

2000

3000

4000

5000

6000

7000

0 100 200 300 400 500

IR

Yil

d(

Kg

/ha

)

Yild=8.7 * IR + 2410.8

r2=0.53

Estimation of yield after flowering

(ETR/ETM) from model(ETR) vegetative period - mean from 10 years


Models Vs. observation for wheat (29 data sets)

Résidus (wheat,data used for validation)

-2000,00

-1000,00

0,00

1000,00

2000,00

3000,00

0 100 200 300 400 500

IRYie

ld (K

g/ha)

0

1000

2000

3000

4000

5000

6000

7000

0 2000 4000 6000

obseved yield (Kg/ha)

estim

ated

yiel

d (K

g/ha

)


- Romanian plain was classified in 6 homogenous zones (soil, climate, agro) - for 4 zones the correlation coefficient increases - for 2 zones the correlation coefficient decreases (hills zones) - temperature influence

- yield was estimated for station and integrated for cultivated surface


Data Spatialisation

grid 20 km x 20km - data set associated (interpolation of missing input data)

- use of data estimated from NOAA-AVHRR satellite images - spatial data

- repetivity (4 images / day)

real T real and interpolated T - kriging method

-20-10

01020

3040

1 22

43

64

85

106

127

148

169

190

211

232

253

274

295

316

337

358

days

T (

°C

)

Tréelle

Tinterpol.


NOAA - AVHRR imageschannel 1(visible) channel 2(NIR) channel 3(MIR) channel 4 channel 5 (IR thermal)=0.58-0.98m =0.72-1m =3.55-3.9 m =10.3-11.3 m =11.5-12.5m


Image reception

hrp format

Image import ERDAS Imagine:

Data calibration for AVHRR channels

1, 2, 3 in radiance or albedo values 4, 5 in temperature

geometric corrections

Image Process ERDAS Imagine:

Reprojection

NDVI Surface temperatureactual evapotranspiration

surfaceemissivity

albedo


NORMALISED DIFFERENCE VEGETATION INDEXNORMALISED DIFFERENCE VEGETATION INDEX CHANEL 2 - CHANEL 1

NDVI = ---------------------------------

CHANEL 2 + CHANEL 1

CANAL 2 - near infrared radiation

CANAL 1 - visible radiation

LEGEND< 1 0.1 0.2 0.3 0.4 0.5 0.53

NDVI 12 June 2000

Reflectance for green leafswavelength (um)

Reflectance for vegetation and soil

wavelength (um) 0.4 0.5 0.6 0.7 0.8 0.9

0.4 0.6 0.8 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8

soilgreen grass

dry grass

blue green red near infrared

visible near infrared


NORMALISED DIFFERENCE VEGETATION INDEX - daily values NORMALISED DIFFERENCE VEGETATION INDEX - daily values 22 June - 26 June 2000 and 5 days value

obtained by MAXIMUM VALUE COMPOSITE


Broad band ALBEDO obtained from the combination of Broad band ALBEDO obtained from the combination of albedo values for channels 1 and 2 albedo values for channels 1 and 2

6 June 2000

d = bo+b1*a1 + b2*a2

where:

a1,a2 albedo values for channels 1,2

bo, b1 si b2 coefficients b1 = 0.494*NDVI2 - 0.329*NDVI + 0.372

b2 = -1.437*NDVI2 + 1.209*NDVI + 0.587

0.05-0.10.1-0.20.2-0.30.3-0.4clouds

Legend


SURFACE EMISSIVITY 12 June 2000


SURFACE TEMPERATURE 6 June 2000 split window methodSURFACE TEMPERATURE 6 June 2000 split window method

<18 20 22 24 26 28 30 32 34 36 38 >40


ACTUAL EVAPOTRASPIRATION ACTUAL EVAPOTRASPIRATION

Image data NOAA-AVHRR 12, 13, 14, 16

(Ts-Ta) daily, 5 days,10 days values

ETR = Rn + A+B(Ts-Ta)daily values

ETR = Rn + A + B (Ts-Ta) daily, 5 days, 10 days values

Surface temperature(Ts) split-window

method

Meteorologicalstations

Maximum airtemperature (Ta)

1 2 3 4 5 5.2 FOREST

ETR (mm)

ACTUAL EVAPOTRANSPIRATION ESTIMATED FROMNOAA-AVHRR image 12 June 2000


SURFACE TEMPERATURE (covered with vegetation) split-windows method

20 June 1999 22 June 2000

TEMPERATURA SUPRAFETEI (o C)TEMPERATURA SUPRAFETEI (o C)

15 - 20 25 - 30 20 - 25 30 - 32 35 - 4030 - 3520 - 30< 25 40 - 45.3


NDVI - 4 April 2001 Surface emissivity 4 April 2001


Surface temperature (covered with vegetation)4 April 2001

Actual evapotranspiration 4 April 2001


CONCLUSION

1. For 3 years estimated yield was 200 kg/ha to the real yield

2. Adaptation of the improved water balance model for yield forecast

3. Validation of data obtained from NOAA-AVHRR images using measured data

4. Estimation of : LAI (leaf area index)

FPAR (photosinteticaly active radiation)

5. Use of data obtained from NOAA-AVHRR images in the model

summer colloquium on the physics of weather and climate adaptation of a hydrological model to...

Documents