Title

Aspect (20m grid) measured in degrees 

Alternate title

ASPECT20 

Purpose

Aspect data used to identify landscape units receiving greater solar exposure. Relevant to Fire Management and environmental modelling. 

Credit

Sam Ebert, DSE Wodonga Craig Hamilton, DSE Wodonga Terry McLLean, DPI Rutherglen 

Supplemental Information

Relationship to other Datasets: The layer is derived using ESOCLIM and DEM250. For a given area one can expect high correlations between RAIN<month> and DEM250 Current Design Issues: The layer is a raster dataset, ie. a GRID. To reduce disk storage it is stored as an integer value grid with precision maintained to two decimal places using: value = mm/annum * 100. Future Design Issues: As DEM250 is replaced by a higher resolution DEM it may be appropriate to re-calculate the rainfall estimates. For specific areas it will be appropriate to use additional rainfall data to update the ESOCLIM surfaces and generate higher resolution rainfall estimates. Layer design should be revised at that time. Related Documents: None ESOCLIM documentation (CLIM_GRD.DOC) ANUCLIM Users Guide 

Status

Completed  

Horizontal Accuracy

100m  

Code

4283 

Maintenance and update frequency

Irregular  

Title

DIGITAL Arc/Info Revision 7 Grid library 2 

Topic category

• Geoscientific information

Use limitation

Available under licence Fire Management Environmental Modelling 

Classification

Unclassified  

Statement

Dataset Source: The dataset is generated from ArcInfo Workstation grid, based on the VICMAP_ELEVATION_DTM_20M dataset. Aspect generated as degrees (0-360). Dataset Originality: Derived 

Description

The dataset is generated from ArcInfo Workstation grid, based on the DEM25 dataset. Aspect generated as degrees (0-360). 

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 VICMAP_ELEVATION_DTM_20M. 

Conceptual Consistency

Missing Data

Comments

Complete for the state. Complete for all Victorian Catchment Management Authority (CMA's) areas. 

Excess Data