Title
Mean annual and monthly canopy transpiration (mm) in the "Agric" (present day) and "Base" (pre-1788) scenario

Custodian
CSIRO Land & Water

Jurisdiction
Australia
Description
Abstract
Definition:  Mean annual (00) and monthly (01...12) transpiration (mm) from the plant canopy for the period 1980-1999.  

Interpretation:  Canopy transpiration is far more spatially variable than potential evaporation, reflecting the effects of water limitation in most areas of the continent. Both the annual mean and seasonal pattern broadly resemble the corresponding patterns for rainfall. Canopy transpiration maps have more "contrast" (relative variation) than the total evaporation or rainfall maps because transpiration is a small component of total evaporation in areas of low plant cover (the remainder being soil evaporation).  The partitioning between soil evaporation and canopy transpiration in the model is determined by leaf area index.

Notes: These are model-based estimates from the BiosEquil model. Results are given for the "Base" (pre-1788) and "Agric" (present day) conditions. The "Agric" case includes current agricultural inputs of water from irrigation.

EvapCanopy.00.Agric, EvapCanopy.01.Agric ... EvapCanopy.12.Agric - Mean annual and monthly canopy transpiration (mm) in the "Agric" (present day) scenario

EvapCanopy.00.Base, EvapCanopy.01.Base ... EvapCanopy.12.Base - Mean annual and monthly canopy transpiration (mm) in the "Base" (pre-1788) scenario

Data is in geographics and GDA94

Search Word(s)
VEGETATION
VEGETATION Maps
VEGETATION Models

Geographic Extent Name(s)

OR
Australia

Geographic Extent Polygon(s)

Data Currency
Beginning date
30Aug2001

Ending date
30Aug2001
Data Status
Progress
Complete

Maintenance and Update Frequency
Irregular.  
Access
Access Constraints
The data are subject to Commonwealth of Australia Copyright. A licence agreement is required. 

Stored Data Format
Arcview binary grid format, single precision


Available Format
Arcview binary grid format, single precision

Data Quality
Lineage
Surfaces supplied here are outputs from the BiosEquil equilibrium model for water, carbon, nitrogen and phosphorus flows in the landscape (Raupach et al. 2001a,b). They are the results of equilibrium modelling for average monthly and annual conditions for the period 1980-99 (where possible).  Data used as inputs to the model include meteorological surfaces of daily gridded data at 0.05° spatial resolution (for Australia) supplied by the State of Queensland through the Department of Natural Resources (Jeffrey et al. 2001) , land-use data for 1996 supplied by the Bureau of Rural Sciences (BRS 2000), fertiliser data supplied by Doug Reuter for the period 1989-1994 (Reuter 2001), soil characteristics for current conditions derived from the Atlas of Australian Soils (McKenzie et al. 2000), and vegetation characteristics (Leaf Area Index) supplied by Lu et al. (2001).  The Australian continental land mask used for this exercise was derived from an Arcview vector-to-grid conversion of the AUSLIG Topo-2.5m coastline (AUSLIG 1998), with a grid resolution of 0.05°.  For references see Additional Metadata field.


Positional Accuracy
Refer to lineage and metadata for model inputs. 

Attribute Accuracy
Accuracy of model results are a function of the accuracy of model representations of physical processes as well as the accuracy of input data and its spatial and temporal representativeness. Refer to the description of the BiosEquil model (Raupach et al., 2001) and the lineage and metadata for model inputs.  

Logical Consistency
In all cases, annual series or monthly series were temporally averaged for the period supplied.  Model inputs were supplied in differing spatial frameworks and were aggregated, disaggregated, resampled or regridded to match the 0.05° land mask derived from Auslig's Topo-2.5m. 

Meteorology: The original 0.05° data were regridded with a 0.025° shift to match the model analysis grid, using linear-weighted averages of the 4 surrounding cells.  

Land-Use:  Data supplied at 0.01° resolution were resampled and masked with a 9-second overlay of waterbodies (Graeme Priestley, CSIRO Land & Water), and used to construct proportion-of-land-use maps at 0.05°.

Fertiliser:  Fertiliser amounts were supplied as annual values per class of crop per statistical local area.  The boundaries of statistical local areas, combined with derived proportional-land-use-maps were used to distribute annual fertiliser amounts across SLAs at 0.05° resolution, for those months broadly identified as the 'fertilising season' for horticulture, permanent cropping, and improved pasture.  Annual average fertiliser amounts per SLA were conserved in all cases.

Soil types supplied as a vector coverage were regridded using a Arcview vector-to-grid conversion to 0.05°.  Cells at 0.05° were assigned the soil type of the dominant soil.  Soil characteristics were determined from the associated Atlas of Australian Soils lookup table.

After regridding to 0.05°, all input data were compared to the analysis landmask for consistency at the coastlines in a two step process.  1) All input data occurring on non-land cells were discarded.  2) Land cells having no input data were assigned the value of the nearest input datum determined by a clockwise spiralling-outward search starting with the cell immediately to the east of the empty cell.

Completeness
Data are spatially complete with respect to the 0.05 degree land mask used in the analysis.


Contact Information
Contact 
Organisation
CSIRO Land & Water

Contact Position
Theme 5.4a Data Manager

Mail Address
GPO Box 1666

Suburb or Place or Locality
Canberra

State
ACT

Postcode
2601

Telephone
02 6246 5554

Facsimile
02 6246 5560

Electronic Mail Address
peter.briggs@cbr.clw.csiro.au


Additional Metadata
Additional Metadata
AUSLIG (1998) MAPDATA TOPO-2.5M Topographic Data. Metadata: http://www.auslig.gov.au/meta/meta37.htm
Jeffrey SJ, Carter JO, Moodie KB, Beswick AR (2001) Using spatial interpolation to construct a comprehensive archive of Australian climate data. Environmental Modelling & Software 16:309-330.
Lu H, et al. (2001) A robust model to separate remotely sensed vegetation indices into woody and non-woody cover and its large-scale application using AVHRR NDVI time series.  In preparation.
McKenzie NJ, Jacquier DW, Ashton LJ, Cresswell HP (2000) Estimation of soil properties using the Atlas of Australian Soils. Technical Report 11/00. CSIRO Land & Water, Canberra, Australia.
Raupach MR, Kirby JM, Barrett DJ, and Briggs PR (2001a) Landscape balances of water, carbon, nitrogen and phosphorus:  (1) project description and results. Technical Report xx/01. CSIRO Land & Water, Canberra, Australia (in preparation).
Raupach MR, Kirby JM, Barrett DJ, and Briggs PR (2001b) Landscape balances of water, carbon, nitrogen and phosphorus:  (2) model description. Technical Report xx/01. CSIRO Land & Water, Canberra, Australia (in preparation).

Metadata date
30Aug2001

