Maite Guardiola and Bart Nijssen

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Distributed Hydrologic Model for Nam Ken and Mae
Sa

• Maite Guardiola and Bart Nijssen
• June 1st and 2nd

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• Location
• Watersheds information
• Mean temp, prcp, wind, flow, stations
• Meteorological data
• Field data
• Soil Soil analysis, TDR tests, SMR curves,
  Infiltration tests
• Vegetation Vegetation maps, LAI
• DHSVM
• Processes (ET, infiltration, subsurface flow,
  groundwater flow)
• Forcing and parameters
• First model runs
• Calibration procedure
• Future goals

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Mae Sa - Thailand, Chiang Mai Nam Ken -
China, Yunnan Province, Xishuanbanna prefecture
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MAE SA

• 3 met stations (black)
• 3 sm / rain gauges (red)
• 1 sm (red)
• 5 rain gauges (blue)
• Mean Annual Values
• Prcp 1300 mm
• Temperature 23C
• Streamflow 2.63 m3/s
• Wind speed 0.8 m/s
• Area 75.4 km2
• Runoff Coef 0.17
• Data Start 06/02/2004
• Ends 10/31/2005

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Nam Ken
Mean Annual Values Prcp 1380 mm Temperature 18
- 23C Streamflow - m3/s Wind speed 2.1
m/s Area 68.9 km2 Runoff Coef 0.25 Data Start
05/18/2004 Data Ends 09/21/2005

• 3 met stations (black)
• 4 sm / rain gauges (red)
• 3 rain gauges (blue)

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Meteorological Data Treatment

• Mets stations
• Precipitation, Temperature, Wind speed, Rel.
  Humidity
• Check for missing time steps, or double
• 20 min ? 1 hr time step
• Checking correlation
• Filling gaps doing interpolation

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Meteorological Data Treatment
Temperature C
Temperature C
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Meteorological Data Treatment

• Mets stations
• Precipitation, Temperature, Wind speed, Rel.
  Humidity
• Check for missing time steps, or double
• 20 ? 1 hr time step
• Checking correlation
• Filling gaps doing interpolation
• Shortwave radiation ? 0 at night (Short radiation
  lt 0 no missing)
• Albedo reflected / incident ? average value
  during the day.

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Albedo Nam Ken
2004
2005
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Albedo - Mae Sa
2004
2005
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Soils and Vegetation data

• Soil data
• Soil analysis and in situ descriptions
• Air infiltrometer
• TDR measurements
• Soil moisture retention curve
• Soil moisture calibration
• Vegetation data
• LAI
• Vegetation classification

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Soil analysis Bulk Density
Nam ken (China) Mae Sa (Thailand)
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Soil analysis Base Saturation and pH
Groundwater
Alfisols
Ultisols, Oxisols
Groundwater
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• Humid and warm regions
• Intense weathering
• Increase clay content with depth
• Quartz, kaolinite and Fe-oxides
• Nutrients in the upper cm

Technically Ultisols Argillic horizon BS lt 35
_at_ pH 8.2 SMAT 8 C Oxisol Oxic horizon
Clay content gt 40 SMAT 8 C
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Soil analysis Bulk Density
Nam ken (China) Mae Sa (Thailand)
Ultisols ? Oxisols
Ultisols
Aquult
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Soils
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Soils
430
429 Met Station
429
428
432
423
433
426
424
425
428
433 Met Station
421
427
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Soil analysis Bulk Density
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Clay content
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Measuring Kmax Kvert Air-entry infiltrometer
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TDR Fast measure of ? in the field
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TDR Porosity Ksat
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Soil Moisture Retention Curve

• Some problems with
• the Pressure Chamber
• the measurements
• Results in a few months

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Soil description and TDR proves
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Soil Moisture Calibration
Nam Ken (351)
Mae Sa (429)

• Red ? Surface
• White ? 100 cm
• Blue ? 200 cm

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LAI from MODIS 15 V4
10 May 2005
18 May 2005
26 May 2005
12 June 2005
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Vegetation
Secondary Vegetation
Rice Paddies
Reservoir
Secondary Shrub
Barren
Cultivated Crops
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Evergreen
Paddy Fields
Trees - Orchards
Reservoir
Green Houses
Buildings
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DHSVM Hydrology Vegetation model

• Overstory / Understory
• 3 layers of rooting zone
• Saturated subsurface flow

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DHSVM

• Unsaturated flow ? Darcy (Unit gradient)
• Lower root zone ? Water table
• 3-D surface, subsurface saturated flow

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Meteorological Data

• Air temperature
• Wind Speed
• Relative Humidity
• Incoming shortwave radiation
• Incoming longwave radiation
• Precipitation
• Optional
• Precipitation lapse rate
• Temperature lapse rate
• Soil temperature
• Wind direction

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Soils

• Measurements and Analysis
• Air entry infiltrometer
• TDR
• Soil profiles description
• Soil analysis
• Literature Calibration
• Authomatically generated
• Slope, landscape position

• DHSVM input
• Kmax, Kvert
• Porosity, Pore size distribution, air pressure,
  ?FC, ?W, ?b
• Albedo, Klat
• Soil Depth

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Unsaturated Flow parameters

• Brooks Corey parameters? using texture (clay,
  silt and sand ) and following Tomasella and
  Hodnett (1998) Pedo Transfer function.
• Air pressure
• Pore size distribution index
• Saturated water content
• Residual water content

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Vegetation

• Measurements and Analysis
• Literature Observations
• Soil profiles description
• Modis Literature

• DHSVM input
• Evap. Parameters
• Over and Understory
• Root zones and
• Monthly LAI / Albedo

Evaporation Parameters Fractional Coverage, Hemi
Fract Coverage, Truck Space, Aerodynamic
Attenuation, Clumping Factor, Leaf Angle A B,
Scattering Parameters, Mass Release Drip Ratio,
Height, Maximum and Minimum Resistance, Moisture
Threshold, Vapor Pressure Deficit and Rpc
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Initial runs

• Measured and Literature parameters
• No calibration done
• Comparisons with
• Streamflow observations
• Soil moisture observations

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• Vol. Obs / Vol. Sim 0.54
• Nash Sutclife -5.0

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Initial runs
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Soil moisture
351
359
356
356 Met station
surface
351 Met station
surface
0.5 m
1.0 m
1.0 m
2.0 m
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Vol. Obs / Vol. Sim 0.6 Nash Sutclife -9.9
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Initial runs
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433 Met station
surface
429
0.2 m
433
1.0 m
421
421 Met station
surface
1.0 m
2.0 m
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Calibration procedure

• Update the meteorological record to two years
• Sensitivity analysis
• Klat, Soil depth (root depth), Kvert, LAI,
• Decide parameters to calibrate the model
• the most sensitive
• the least confident (klat, Kvertical)

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Future work
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