Indicator description

Why is it indicative

Data

Acknowledgment

Indicator description

Up to 30 land cover classes were identified from Landsat satellite remote sensing data from images captured at September 1999 for the south-east and November 2000 for the north (descriptions of the classes can be downloaded. Classification statistics were prepared for the statistical divisions of greater Hobart and greater Launceston. The 30 classes were grouped into land use classes, natural land cover classes and other classes. Woody vegetation change analysis was undertaken for Landsat data acquired for the previous SoE report (around 1994) to the current SoE report. The results, available as a map of woody vegetation change, are also presented for Hobart and Launceston statistical divisions.

Why is it indicative

The land cover classification assists in providing an indication of the major land-related issues occurring within each statistical division. Comparisons over time will assist in identifying the pattern of land use change and intensification.

Data

Land use in Greater Hobart and Launceston

Land use classification of Greater Hobart

Land use	area (ha)	% total
Airports/aerodromes	634	0.7
Aquaculture	3	0.0
Biodiversity	549	0.6
Commercial services	172	0.2
Cropping	61	0.1
Defence	84	0.1
Defence facilities	0	0.0
Effluent pond	11	0.0
Electricity generation/transmission	106	0.1
Environmental	2	0.0
Estuary/coastal waters	14	0.0
Estuary/coastal waters - conservation	21	0.0
Grazing modified pastures	16,491	18.4
Grazing natural vegetation	10	0.0
Habitat/species management area	3	0.0
Intensive horticulture	37	0.0
Irrigated cropping	455	0.5
Irrigated modified pastures	117	0.1
Irrigated perennial horticulture	331	0.4
Irrigated seasonal horticulture	87	0.1
Irrigated vine fruits	46	0.1
Landfill	125	0.1
Managed resource protection	692	0.8
Manufacturing and industrial	671	0.8
Marsh/wetland	547	0.6
Marsh/wetland - conservation	46	0.1
Mines	271	0.3
Mining	280	0.3
Natural feature protection	226	0.3
Navigation and communication	1	0.0
Other conserved area	12,419	13.9
Plantation forestry	1,404	1.6
Ports and water transport	104	0.1
Poultry	3	0.0
Production forestry	1,121	1.3
Protected landscape	3,088	3.5
Public services	467	0.5
Quarries	36	0.0
Railways	16	0.0
Recreation and culture	1,235	1.4
Remnant native cover	26,738	29.9
Research facilities	20	0.0
Reservoir	147	0.2
River	51	0.1
River - conservation	93	0.1
Roads	216	0.2
Rural residential	10,265	11.5
Services	675	0.8
Sewage	30	0.0
Strict nature reserves	415	0.5
Surface water supply	193	0.2
Transport and communication	4	0.0
Urban residential	8,586	9.6
Utilities	3	0.0
Waste treatment and disposal	18	0.0
Water storage and treatment	16	0.0
Totals	89,457	100.0

Source: Andrew Drennen

Land use classification of Launceston

Land use	area (ha)	% total
Airports/aerodromes	184	0.2
Biodiversity	109	0.1
Commercial services	326	0.4
Effluent pond	10	0.0
Electricity generation/transmission	399	0.5
Estuary/coastal waters - conservation	0	0.0
Estuary/coastal waters - intensive use	0	0.0
Grazing modified pastures	36,131	45.0
Grazing natural vegetation	6,261	7.8
Habitat/species management area	993	1.2
Intensive horticulture	3	0.0
Irrigated cropping	1,190	1.5
Irrigated modified pastures	22	0.0
Irrigated perennial horticulture	549	0.7
Irrigated vegetables and herbs	18	0.0
Irrigated vine fruits	181	0.2
Landfill	166	0.2
Managed resource protection	13	0.0
Manufacturing and industrial	1,303	1.6
Marsh/wetland	254	0.3
Marsh/wetland - conservation	116	0.1
Mining	434	0.5
National park	857	1.1
Native/exotic pasture mosaic	82	0.1
Natural feature protection	434	0.5
Navigation and communication	6	0.0
Other conserved area	1,300	1.6
Plantation forestry	668	0.8
Ports and water transport	94	0.1
Production forestry	2,988	3.7
Protected landscape	283	0.4
Public services	375	0.5
Quarries	4	0.0
Railways	138	0.2
Recreation and culture	1,225	1.5
Remnant native cover	11,676	14.5
Reservoir	230	0.3
Residential	134	0.2
River	177	0.2
River - conservation	43	0.1
Roads	186	0.2
Rural residential	5,780	7.2
Services	197	0.2
Sewage	44	0.1
Surface water supply	1	0.0
Urban residential	4,603	5.7
Utilities	48	0.1
Waste treatment and disposal	64	0.1
Water storage and treatment	5	0.0
Totals	80,303	100.0

Source: Andrew Drennen

Landcover classification of Greater Hobart and Launceston

According to this classification, urban and suburban land cover occupies 7.9% of greater Hobart and 9% of greater Launceston. 'Modified' land cover classes that can be identified from Landsat data represent 33.5% of greater Hobart and 45% of greater Launceston. 'Natural' land cover classes account for 61.9% of greater Hobart and 49.6% of greater Launceston. The difference between Hobart and Launceston is due in part to the greater significance of agriculture, pasture and forestry activity around Launceston. The Mt Wellington Park and the Meehan Range in Greater Hobart also occupy a significant area of the greater Hobart statistical division, contributing to the overall proportion of 'natural' land cover.

Greater Hobart			Greater Launceston
	total area (ha)	% Greater Hobart	total area (ha)	% Greater Launceston
Modified land cover classes
Agriculture	3,438.3	2.5	7,219.9	9.0
Forestry Activity	5,917.8	4.4	5,119.8	6.4
Pasture	25,250.6	18.6	16,362.5	20.4
Regrowth	205.1	0.2	167.0	0.2
Suburbs	9,346.0	6.9	5,892.8	7.3
Urban	1,336.1	1.0	1,378.7	1.7
subtotal	45,493.9	33.5	36,140.7	45.0
Natural land cover classes
Alpine	617.9	0.5	7.4	0.0
Alpine scrub	220.9	0.2	-	-
Buttongrass	75.8	0.1	1,121.3	1.4
Coastal scrub	3,286.3	2.4	1,809.4	2.3
Eucalptus coccifera	1,025.5	0.8	1.1	0.0
Eucalptus delegatensis	2,601.3	1.9	781.6	1.0
Dry forest	28,458.6	20.9	14,517.9	18.1
Dry forest (wet)	2,503.1	1.8	911.5	1.1
Grassland	3,294.8	2.4	3,361.2	4.2
Rainforest	926.7	0.7	101.4	0.1
Saltmarsh	2,376.7	1.7	1,088.2	1.4
Scrub/heath	8,221.6	6.0	9,258.4	11.5
Eucalptus tenuiramis	-	-	-	-
Wet forest	5,255.8	3.9	2,190.1	2.7
Wet forest (dry)	2,581.6	1.9	369.7	0.5
Wet scrub	985.1	0.7	793.8	1.0
Wetland	969.4	0.7	1,240.6	1.5
Woodland	20,725.9	15.2	2,299.8	2.9
subtotal	84,126.8	61.9	39,853.2	49.6
Other land cover classes
Cloud	367.0	0.3	790.4	1.0
Shadow	121.5	0.1	13.1	0.0
Water	269.3	0.2	21.7	0.0
Shallow water	96.3	0.1	133.0	0.2
Bare	5,007.6	3.7	3,264.7	4.1
Sand/quartz	427.9	0.3	53.4	0.1
subtotal	6,289.4	4.6	4,276.3	5.3
total	135,910.1	100.0	80,270.1	100.0

Vegetation change

The analysis of woody vegetation change for greater Hobart compares vegetation cover from Landsat satellite images from ~1994 to 1999. The results identify areas that have woody vegetation cover at both dates, areas that have gained woody vegetation cover, and areas that have lost woody vegetation cover. The on-the-ground context in which these changes are occurring is all important: not all vegetation loss may be 'bad' for the environment and not all gains may necessarily be 'good'.

The logging of a plantation such as at Seven Mile Beach, for example, is indicated as vegetation loss even though the environmental consequences of this harvesting on an established plantation are comparatively neutral. Some change may simply be a part of natural cycles, such as regrowth following bushfire. Other limitations of the change detection relate to what it omits. In particular, non-forest vegetation, may have high conservation importance yet the loss of such vegetation can not be identified in change detection from Landsat remote sensing.

Scale and resolution is also important: Landsat data has a resolution of about 25 m² so changes that are finer than this resolution may not be evident but may be just as critical for priority vegetation communities and habitat. The slope, elevation and visibility of vegetation change are also an important part of the on-the-ground context of change. For example, the vegetation change indicated over this period for Mt Nelson and Tolmans Hill does not adequately portray impacts on landscape quality on hillslopes [link the words landscape quality to the issue report on 'landscape quality'].

With noting these issues and limitations, the change detection indicates the following:

• An overall perspective of increasing fragmentation of vegetation in greater Hobart.
   
• Vegetation clearance for housing development at Seven Mile Beach, Tolmans Hill, Mt Nelson, Kingston, Blackmans Bay, and Cremorne.
   
• Plantation regrowth at Seven Mile Beach.
   
• Forestry activity near Magra, north of New Norfolk, and on the eastern side of greater Hobart staistical division indicated by land cover patterns of woody vegetation increase and decrease.
   
• Evidence of the role of parks and reserves in preserving the landscape from land cover change shown by Mt Wellington Park and the Domain.
   
• Significant land cover activity in a belt extending north of Hobart from Bridgewater to Forcett.
   
• An unknown percentage of vegetation loss includes the clearance of vegetation of conservation priority. Comparisons with TASVEG data and with conservation priorities for forest and non-forest components identified by CARSAG would assist in understanding the conservation significance of the changes identified.
   

Acknowledgment

Adapted from Key Land Indicator L 2.4 and 2.5 (Hamblin 1998)