Title

Estimated mean annual monthly evaporation 

Alternate title

EVAP_ANN 

Purpose

Generation of maps showing mean annual evaporation. Generation of maps of isolines of evaporation. Environmental modelling species distributions recharge areas site suitability analyses catchment analyses other 

Credit

Adam Lewis 

Supplemental Information

Relationship to other Datasets: The layer is derived using monthly evaporation estimates (EVAP_{month}), which were summed in GRID. The monthly esimates were produced using ESOCLIM and DEM250. For a given area high correlations between EVAP_ANN and DEM250 can be expected. Current Design Issues: The layer is a raster data set, ie. a GRID. The units of the values are mm/day. Future Design Issues: As DEM250 is replaced by a higher resolution DEM it may be appropriate to re-calculate the evaporation estimates. For specific areas it will be appropriate to use additional evaporation data to update the ESOCLIM surfaces and generate higher resolution evaporation estimates. Layer design should be reviewed at that time. Related Documents: None ESOCLIM documentation (CLIM_GRD.DOC) ANUCLIM Users Guide 

Status

Completed  

Horizontal Accuracy

100m  

Maintenance and update frequency

Not planned  

Title

DIGITAL Arc/Info Revision 7 Grid layer 2 

Topic category

• Climatology, meteorology, atmosphere

Use limitation

licence required 

Classification

Unclassified  

Statement

Dataset Source: The dataset is an output from the ESOCLIM program, which interrogates pre-existing interpolated surfaces using, as input variables, latitude, longitude, and elevation. DEM250 is used to estimate elevation. The original surfaces are interpolations of climate variables using minimum curvature multi-dimensional splining algorithms developed by Dr. Mike Hutchinson of the Centre for Resource and Environmental Studies (CRES) ANU. The interpolations were developed by June McMahon and others at CRES. References are given with the attached documentation (CLIM_GRD.DOC) and further details regarding the derivation process can be obtained from ANUCLIM Users Guide. ESOCLIM is a licensed software, CRES may lay some claim to datasets derived using ESOCLIM. Dataset Originality: Derived 

Description

The program DEM2ESO.AML (A. Lewis, NRS) converts a GRID to an ascii file suitable for input to ESOCLIM and runs the program. A number of small, customised programs are used in this process. Output files are large (160 bytes/cell), prohibiting estimation of multiple variables for large grids in a single pass. This program is developmental at this time. The program ESO2ARC.AML converts ESOCLIM output files to ARC/INFO grids, using standard names for the output grids. 

Classification

Unclassified  

Attribute Quality

Comments

Normally claimed to be within 5% of the actual value. This is based on a generalised cross-validation algorithm which carries out the original interpolation without each point in turn, and compares the interpolated value at that point with the observed value. 

Positional Accuracy

Comments

Precision:10-100m Determination: Based on the input map scale for the data underpinning DEM250. 

Conceptual Consistency

Missing Data

Comments

Complete for the state. Complete for the state. 

Excess Data