Citation

Geoscience Australia provides most of its products for free under a Creative Commons Attribution 3.0 Australia Licence. We only require that you reference the use of our data or information using the following citation:
Hughes, M., 2013. Ecological disturbance index. Geoscience Australia, Canberra.

Abstract

This data represents a dimensionless ecological disturbance index, as the ratio of ecological succession and disturbance recurrence interval times the fraction of the area disturbed in any event. Small values of the ecological disturbance index represent decreasing proportions of time when disturbed/recovering habitats are present.
Google map showing geographic bounding box with values North bound -7.0 East bound 156.0 West bound 110.0 South bound -44.0
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Product Type/Sub Type

dataset - Marine Data

Constraints

license
Creative Commons Attribution 3.0 Australia Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2013

Product Type

dataset

Topic Category

oceans

Keywords

Marine Data
oceanography
seabed
marine
Marine Geoscience

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-7.0
East bound
156.0
West bound
110.0
South bound
-44.0

Lineage

Geoscience Australia's GEOMACS (Geological and Oceanographic Model of Australia's Continental Shelf) model was utilised to produce hindcast hourly time series of continental shelf (~20 - 300 m depth) bed shear stress on a 0.1 degree grid covering the period March 1997 to February 2008 (inclusive). The hindcast data represents the combined contribution to the bed shear stress by waves, tides, wind and density-driven circulation. The ecological disturbance index is calculated using the following equation: ED=FA*ES/RI Where ED is the ecological disturbance index, FA is the spatial fraction multiplier, ES is the ecological succession (in days), and RI is the recurrence interval (in days). In this study, FA was assigned 1.0. ES equals 1 year (365 days) for mud, 3 years (1095 days) for sand and 5 years (1825 days) for gravel. While, RI is the average time between events when the Shields parameter exceeding 0.25 (the geomacs_ri layer).The seabed sediment was classified into gravel, sand or mud using a simple classification scheme (Folk, 1974). Grid cells were assigned to the gravel class if percent gravel was >30, and if the percent gravel was <30 they were assigned to either the sand or mud class depending on which ever had the largest percentage. The sediment grain size data used for this exercise were from the predicted layers of Li et al. (2011). Please refer to Hughes et al. (2010) for further details. Hughes, M.G., Harris, P.T., Brooke, B.P., 2010. Seabed exposure and ecological disturbance on Australia's continental shelf: Potential surrogates for marine biodiversity. Geoscience Australia Record 2010/43, 77pp. Li, J., Heap, A.D., Potter, A., Huang, Z., 2011. Seabed gravel content across the Australian continental EEZ 2011, http://www.ga.gov.au/meta/ANZCW0703014835.html Li, J., Heap, A.D., Potter, A., Huang, Z., 2011. Seabed sand content across the Australian continental EEZ 2011, http://www.ga.gov.au/meta/ANZCW0703014867.html

Digital Transfer Options

onLine

DISTRIBUTION Format

ArcGIS-grid

Distributor

Role
distributor
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address

Metadata File Identifier

e3dd1af5-7afe-50fd-e044-00144fdd4fa6

Metadata Standard Name

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Metadata Standard Version

1.1

Metadata Date Stamp

2013-08-14

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
Downloads
For information on acquiring this product,
please contact Geoscience Australia Client Services via:

fax:
+61 2 6249 9960; or
phone:
1800 800 173 (within Australia);
 
+61 2 6249 9966 (outside Australia).

Please note that support hours are 9 am to 5 pm weekdays