Bushfire CRCBushfire CRCGrassland Curing ProjectGrassland Curing Project

Ian Grant

Bureau of Meteorology

Grassland CuringGrassland Curing

What:

The seasonal dying and drying of grassland

Why:

- An input to fire danger rating systems

- An input to fire behaviour models

Curing input

Fire danger/behaviour output

Fire management decisions

Grassland Curing Index - How it’s done nowGrassland Curing Index - How it’s done now

AVHRR method compares reflectance in two spectral bands

• Developed by CSIRO,

run by Bureau of Meteorology

• Victoria and South Australia only

>95%

>65%

>85%

>45%

>25%

<25%

Bushfire CRC - Project A1.4 Bushfire CRC - Project A1.4 Improved methods for the assessment and prediction of grassland curingImproved methods for the assessment and prediction of grassland curing

Aim:

Develop techniques of grassland curing assessment that are robust, reliable, validated and applicable across Australia and New Zealand

Duration:

July 2004 – June 2010

Field measurement program:

Systematic sampling of fuel moisture content at several sites across Australia and NZ, through three or four seasons

Bushfire CRC - Project A1.4 Bushfire CRC - Project A1.4 Improved methods for the assessment and prediction of grassland curingImproved methods for the assessment and prediction of grassland curing

Approaches:

• Remote sensing (vegetation indices, thermal)

- AVHRR, MODIS

• Pasture growth models

- Assessment, Prediction

• Soil moisture

- Direct measurements

- Indicators

• Drought Code

• Keetch Byram Drought Index

• Soil Dryness Index

- Validate/improve water balance in growth models

Vegetation indices: MODIS vs AVHRRVegetation indices: MODIS vs AVHRR

Curing and soil moisture:Curing and soil moisture:Questions and requirementsQuestions and requirements

• Can progression of visible curing and soil moisture be related?

• Can soil moisture observations improve/validate growth models?

Requires measurements spread through a curing season

Which measure of soil moisture is most appropriate?

• Can fuel moisture content be estimated, or optical estimates improved, with microwave observations of vegetation?

• Co-locate some curing sampling sites with soil moisture sites

General requirements for satellite targets:

- Little topography (over ~11 km2)

- Few or no trees (over ~11 km2)

- A range of grassland types

Other useful measurementsOther useful measurements

• VNIR spectrometer measurements of surface

- ground, air, multiangular?

• Thermal radiometer measurements of surface

- radiometric land surface temperature, multiangular?