Australian Natural Resources Atlas

Publications

Australian Natural Resources Information 2002

National Land and Water Resources Audit, 2002
ISBN: 0 642 37131 8

Appendix 1. Catalogue Of Data Products From Audit Assessments

Digital data products are available for free download over the Internet from the Australian Natural Resources Data Library at adl.brs.gov.au or directly from custodians of the data. The products are designed for analysis and display using geographic information systems.

Documentation for each product is also available through the Australian Spatial Data Directory at http://asdd.ga.gov.au/asdd/ .

Before the data are downloaded, users accept a set of licence conditions that allow royalty-free, non-exclusive use of the data. The licence conditions do not allow the data to be transferred from the licensee to another person or organisation. Data, or any product or service derived from the data, may be commercialised with permission of the owners of the data.

The following catalogue lists some of the data currently available from Audit projects. New data are continually being added as Audit projects conclude.

Agriculture

A spatially consistent subset of agricultural statistics (AgStats) data 1982/83 to 1996/1997

The statistics have been standardised to version 2.6 of the 1996 statistical local area boundaries from the Australian Bureau of Statistics and take into account areas of agriculture from the national land use map (1996/97).

Proportion of land area under irrigation for 1996

The assessment was derived from the map of designated and actual irrigation areas in Australia for 1996.

Agricultural industries—regional boundaries

Climate variables used to determine agricultural water balances

Maps are derived from data from the Bureau of Meteorology, interpolated to a spatial grid of 0.05 degrees of latitude and longitude. Data layers were derived to assess the availability of water for agriculture.

Biodiversity and vegetation

Native vegetation

The maps were derived from the National Vegetation Information System. For present vegetation the nominal scale is 1:100 000-1:250000 for the intensive land use zone and 1:250 000-1:1 000 000 for the extensive land use zone. For pre-1750 vegetation, the nominal scale is 1:1 000 000.

Available maps

Native vegetation information to support regional vegetation management

Landscape health in Australia 2001

An assessment of the relative condition of Australia's bioregions and subregions.

Available maps

Condition
Trend
Landscape stress

Data are available for download from the Environment Australia node of the Australian Spatial Data Directory.

Coasts

Estuary Condition Assessment 2000

Estuary Condition Assessment 2000 assessed the condition of 974 estuaries and classified each estuary by the key geomorphological processes driving it.

Data are available online from Geoscience Australia at www.ga.gov.au/oracle/ozestuaries/

Land

Australian Dryland Salinity Assessment 2000 to 2050

Australia

Groundwater level and trend data are available in southern Australia and more precise assessments have therefore been possible. In northern Australia groundwater data for time-series analysis are very sparse or non-existent. In these regions, salinity assessments have been based on the presence of geology, landscape, regolith, land use and climate attributes which are the other prime drivers of salinity. The national map provides a basis for identifying those regions where more detailed assessments are warranted and where land use changes should be targeted if the risks are to be managed.

Most non-agricultural areas in Western Australia, South Australia and western New South Wales were considered to have a very low salinity risk and were not assessed.

New South Wales

Areas of risk are based on groundwater levels and air photo interpretation. The merged data, at a nominal scale of 1:250 000, show actual areas where dryland salinity or watertables < 2 m have been measured. For the map of salinity extent, every delineated area is validated by either air photo data or by one or more groundwater bores. The area at risk is regarded as conservative due to limitations in the spatial coverage of air photo and groundwater bore data.

Coastal catchments are not represented in the prediction for 2050 due to the paucity of groundwater data.

Queensland

Estimates of projected dryland salinity hazard for 2050 were based on integrating attributes that drive salinisation (e.g. geology, landscape features, regolith depth and type, land use and climate). Groundwater data for assessing salinity risk in Queensland are extremely limited. Groundwater trend analysis was possible only in the Condamine-Balonne and Border Rivers catchments of the Murray-Darling Basin. Information has been prepared at a scale of 1:2500 000.

South Australia

The South Australian maps of dryland salinity risk in 2000, 2025 and 2050 are at 1:250 000 scale.

Current dryland salinity areas were interpreted from aerial photography and existing topographic data. Some additional areas were digitised from topographic base maps.

Areas thought to be at risk from dryland salinity by 2025 and 2050 are based on groundwater trends, topography and professional judgement.

Tasmania

The Tasmanian Department of Agriculture carried out a series of reconnaissance surveys of the State's land systems between 1980 and 1989. The land systems were differentiated initially by examining geomorphic patterns on aerial photographs in conjunction with geologic, topographic and climatic maps. The maps of salinity are based on land systems at 1:250 000 scale containing areas of salinity in 1992, and land systems on agricultural land containing areas of salinity in 2000.

Victoria

The Victorian dryland salinity assessment spatial data comprises:

Western Australia

The Western Australian dryland salinity assessment spatial data were derived from detailed soil-landscape mapping at 1:500 000 scale and comprise three maps:

The risk of shallow watertables was derived from analysis of the groundwater depth and trend over time. As dryland salinity is caused by shallow watertables, the risk of salinity is inferred from the risk of developing shallow watertables. Not all shallow watertables will be saline however. Estimates and projected risk areas are based on analysis of existing groundwater levels and trends at a scale of 1:250000 based on the mapping of soil systems.

The assessment was restricted to the south-west of Western Australia where dryland salinity or susceptibility is widespread.

Australian groundwater flow systems (1:5 000 000)

These flow systems were identified using a combination of geology, geomorphology and elevation information at a national scale.

Australia-wide land use (1996/97) (1:1 000 000)

Information about the distribution of protected areas, forest types, agricultural commodities and irrigated areas is available in the database.

The agricultural commodities and irrigation layers show specific agricultural land uses and were constructed by automated analysis of a one year sequence of normalised difference vegetation index images using control sites to provide known agricultural land uses at known locations.

Fitzroy River catchment land use 1996/97 (1:100 000)

The data are attributed using the Australian Land Use Management Classification at 1:100000 scale. The data were collected using satellite imagery interpretation and extensive fieldwork.

Gippsland land use 1996/97
(1:100 000)

The map is based on data held at the Victorian Department of Natural Resources and Environment, satellite imagery, Australian Bureau of Statistics agricultural statistics and information collected in the field. The data are attributed using the Australian Land Use Management Classification at 1:100 000 scale.

Mt Lofty land use 1996/97 (1:100 000)

The data are attributed using the Australian Land Use Management Classification at 1:100000 scale.

Western Australia land use 1999 (1:100 000)

The data are attributed using the Australian Land Use Management Classification at 1:100000 scale.

Soil properties—Australian Soil Resources Information System (ASRIS)

The maps of soil properties available from the Australian Soil Resources Information System include:

Soil depth

Soil depth defines the zone available for plant roots to grow in and determines the size of the soil water store. Maps are available of solum depth, topsoil depth and subsoil depth.

Solum depth refers to total depth of soil (A and B horizons). It does not include the unconsolidated or partially weathered material which underlie the soil, where soil-forming processes are not obvious.

Topsoils (A horizons) are defined as the surface soil layers in which organic matter accumulates and may include dominantly organic surface layers.

Subsoils (B horizons) contain less organic matter than topsoils and may often have a zone of accumulation of clays, carbonates or iron and aluminium oxides.

Particle size distribution and soil texture

Soil texture is strongly related to many other soil physical properties (e.g. soil structure, bulk density, porosity, permeability) and chemical properties (e.g. cation exchange capacity). Soil texture is often used to estimate other soil properties (particularly soil water properties) if no direct measurements are available. Maps are available of:

Bulk density (topsoil and subsoil)

Bulk density is the weight of a dry soil in a unit of volume and gives a measure of soil porosity.

Knowing the bulk density of a soil is important as it can help determine how much air or water can be stored and moved through the soil. Bulk density also indicates how tightly soil particles are packed together.

Soils with low bulk density are generally more suitable for agriculture, since this indicates high pore space (and so greater potential to store water) and roots extend more readily through a soil of low bulk density.

Available water capacity (topsoil and subsoil)

The available water capacity gives an approximation of the water storage capacity of a soil and so is important in assessing suitability for agriculture. Available water capacity is the amount of water in the soil horizon that can be extracted by plants.

Total nitrogen

Nitrogen is an element that is part of all living matter. Most soil nitrogen is associated with organic compounds such as proteins or fertiliser inputs.

Total phosphorus and extractable phosphorus (topsoil)

Phosphorus is an element that is essential for plant growth. The total phosphorus content of most Australian soils is low by world standards and many soils require phosphate fertilisers to maximise production.

Percentage organic carbon (topsoil and subsoil)

Soil organic matter content is an indication of natural soil fertility and is a balance between input of surface litter (fallen leaves and dead organisms) and the rate at which microbes break down organic compounds.

Saturated hydraulic conductivity (topsoil and subsoil)

Saturated hydraulic conductivity is a measure of the permeability of a soil (i.e. how quickly water can move through the soil when it is saturated). Soil permeability, in conjunction with water storage capacity, is fundamental to controlling the soil-water regime, which determines the suitability of land for a range of purposes.

Soils with a slow hydraulic conductivity at or near the soil surface (e.g. < 30 mm/hour) cannot transmit water from heavy showers of rain and this can lead to excessive run-off and potentially to erosion. Run-off also represents a loss of water that could have otherwise been available to plants.

pH

Soil pH is a measurement of the relative acidity or alkalinity of the soil, providing a guide to the overall chemical balance of the soil. Soil pH is an important factor in plant growth because pH determines the availability of soil nutrients to plants.

pH buffering capacity

Soils have an intrinsic ability to resist pH change, either from a decrease through an input of acid or from an increase through the application of lime. This is known as pH buffering capacity and is determined by a chemical test. Estimates of pH buffering capacity are important for providing advice on levels of lime required to reduce soil acidity.

Erodibility

Resistance is a function of:

Except where gullying is extreme, only the topsoil is subject to erosion, so a map of estimated erodibility has been produced only for the topsoil.

Lithology (geology) 1:2 500 000 scale

The lithology classes were chosen as being of significance for soil formation and relate mainly to chemical composition. Data are presented as a grid with cells 0.0025 degrees of latitude and longitude.

Landscape carbon balance

The following data cover catchments with areas of intensive agriculture.

Mean annual and monthly net primary productivity

Net primary productivity is the net rate at which plants build up carbon from the atmosphere by photosynthesis. It is equal to the difference between carbon gained (positive) by plant photosynthesis and the carbon lost (negative) by plant respiration, per unit land area per year. The carbon gained by the landscape is either lost through litter and soil respiration and disturbance processes (e.g.grazing, harvest and fire) or accumulates in storage. Net primary productivity is the primary driver of the carbon and nutrient cycles and the primary controller of the size of carbon and organic nitrogen stores in the landscape.

Mean annual store of carbon in plant biomass

The mean annual store of carbon in plant biomass (kilograms of carbon per hectare) incorporates all above-ground and below-ground carbon in living plants, but not plant litter or soil organic carbon. This is the basic measure of the store of plant biomass on the landscape.

Mean annual store of soil organic carbon for the present day and pre-1788 scenario

The mean store of soil organic carbon (kilograms of carbon per hectare), includes all non-living soil storage pools including plant litter. This is the basic measure of the store of soil organic matter in the landscape. Soil carbon stores—similar to those of plant and litter carbon—are strongly controlled by net primary productivity and hence by rainfall and saturation deficits. All these carbon stores are also modulated by temperature because low temperatures slow the decay of plant material and high temperatures promote rapid decay. Most soil carbon occurs in the upper soil layer.

Landscape nitrogen and phosphorus balances

Mean annual store of total plant-available soil nitrogen

Total plant-available soil nitrogen consists of the organic nitrogen in litter and soil and the mineral plant-available nitrogen (including both ammonium and nitrate). The pattern of this store strongly resembles the maps of carbon storage and net primary productivity because the nitrogen stores are coupled to carbon stores through well defined nitrogen/carbon ratios in leaves, wood, roots, litter and soil organic matter.

Mean annual concentration of dissolved nitrogen and phosphorus in soil water

Dissolved nutrient concentrations were determined to assess the change on nutrient stores principally because of introducing agriculture into the landscape. Dissolved nutrient concentrations were modelled and calculated assuming that plant available pools of mineral nitrogen and labile phosphorus occur in solution. The dissolved nitrogen concentration is the ratio of mineral nitrogen store to soil water store. Dissolved phosphorus concentration is the ratio of labile phosphorus store to the soil water store.

Mean annual store of total plant-available soil phosphorus

Total plant-available soil phosphorus consists of the organic phosphorus in litter and soil, and the plant-available mineral phosphorus. Plant-available phosphorus stores are less than the total phosphorus store in the landscape, because much of the mineral phosphorus in the soil is tightly chemically bound to the soil matrix and is therefore only weakly available for plant growth or unavailable in time scales less than centuries.

Mean annual nitrogen fertilisation

Before the advent of European-style agriculture, the amount of nitrogen in the landscape was dominated by the input of nitrogen from natural fixation, with a small contribution from atmospheric nitrogen deposition. The counter balancing losses of nitrogen occurred through a mixture of volatilisation, leaching and disturbance. With the advent of European-style agriculture, the nitrogen budget changed substantially: the largest source remains fixation, greatly enhanced in agricultural areas by sown legumes. Losses occur through grazing by stock, leaching and volatilisation.

Mean annual phosphorus fertilisation

Mean annual nitrogen leaching

This is the loss of nitrogen from the plant-available mineral pool by transport in dissolved form, mainly through deep drainage of water from the soil store.

Mean annual nitrogen volatilisation

This is the loss of nitrogen from the landscape to the atmosphere in the form of nitrogenous gases, including nitrous oxide and others.

Mean annual phosphorus leaching

This is the loss of phosphorus from the plant-available mineral pool by transport in dissolved form, mainly through deep drainage of water from the soil store.

Mean annual store of mineral nitrogen

Of the plant-available nitrogen, only a small fraction is in mineral form. The rest is 'in use' in biomass or 'on return' through litter and soil organic matter. Nitrogen storage maps strongly resemble the maps of carbon storage and net primary productivity, because the nitrogen stores are coupled to carbon stores through well-defined (through not constant) nitrogen/carbon ratios in leaves, wood, roots, litter and soil organic matter.

Mean annual store of plant-available mineral phosphorus

Plant-available mineral phosphorus stores is less than the total phosphorus store in the landscape because much of the mineral phosphorus in the soil is tightly chemically bound to the soil matrix and is therefore only weakly available for plant growth or unavailable in time scales less than centuries.

Mean annual nitrogen fixation

Mean annual deep drainage

Mean annual deep drainage is the volume of water draining below the root zone. Significant deep drainage is confined to irrigation areas and wet areas where rainfall exceeds potential evaporation.

Erosion by water

The following data cover catchments with areas of intensive agriculture.

Erosion gully density

Approximately 325 000 km of gullies across the assessment area have eroded about 4.4 billion tonnes of sediment since European settlement.

River bed sediment accumulation

Mean annual suspended sediment yield per hectare of catchment

Ratio of current suspended load to pre-European suspended load

River sediment loads are generally 10 to 50 times greater than pre-European loads in intensively used river basins.

Contribution of sediment to the coast

Ninety percent of the suspended sediment loads reaching estuaries are derived from 20% of catchment areas.

Pre-European and present hillslope erosion

Mean annual sheet-wash and rill erosion rate

The Revised Universal Soil Loss Equation was used to predict mean annual sheet-wash and rill erosion potential across Australia under current land uses.

Ratio of hill slope erosion present to pre-European

The ratio ranges from 1 (signifying no change since European settlement) to large values indicating large increases in erosion.

Sediment and nutrient supply to river links

This vector coverage of the streams was generated from a 9-second (approximately 250 m) digital elevation model from the Australian Surveying and Land Information Group. The streams have been attributed with sediment and nutrient source, sink, load and delivery information.

Sediment contributed from areas draining to river links

Factors contributing to sheet wash and rill erosion

Rainfall erosivity (R factor)

Rainfall erosivity refers to the erosive energy of rain, a function of the total amount of rainfall and its intensity in a typical rainfall event. It varies strongly across Australia and is highest in coastal regions of northern Australia.

Perennial cover (C factor)

Vegetation cover strongly influences erosion potential. As perennial plant cover changes away from the coast, so too does erosion potential.

Mean slope (S factor)

Slope length (L factor)

Slope length is the distance from ridge top to valley bottom. The values represent averages over a 1 km radius. The L factor of the Revised Universal Soil Loss Equation is derived from slope length.

People—social and economic dimensions of natural resources

Age and experience

Median age of farmers (1991-1996)

Assessment uses statistics from the Australian Bureau of Statistics population and housing census. The median age of farmers and farm managers increased from 46 to 48 years between 1991 and 1996, whereas over the same period the average age of the metropolitan population increased by only one year.

Education and training

Formal education (1991-1996)

Data are presented by statistical local areas and are from the Australian Bureau of Statistics population and housing census.

Higher qualifications (1991-1996)

Data are presented by statistical local areas and are from the Australian Bureau of Statistics population and housing census.

Basic vocational (1991-1996)

Data are presented by statistical local areas and are from the Australian Bureau of Statistics population and housing census.

Skilled vocational (1991-1996)

Data are presented by statistical local areas and are from the Australian Bureau of Statistics population and housing census. Skilled vocational qualifications is defined as having completed a course lasting two to four years and typically involves on-the-job training for working in a specific vocation, trade or craft that requires a high degree of skill.

Recent training (1996/97 to 1998/99)

Data are presented by statistical divisions and are from the Annual Farm Survey conducted by the Australian Bureau of Agricultural and Resource Economics during the period 1996/97 to 1998/99. Continuing education throughout life is linked to farm profitability; one study found that farm incomes tend to be higher as farmer participation in training increases.

Farm family characteristics

Families with dependant children (1996/97)

Farm structure

Median Estimated Value of Agricultural Operations (1996/97)

This is a measure of the value of the annual production of a farm business, estimated from physical livestock and crop information provided in the agricultural census undertaken by the Australian Bureau of Statistics and three-year weighted average prices derived from the Annual Farm Survey undertaken by Australian Bureau of Agricultural and Resource Economics.

Farm area (1996/97 to 1998/99)

Assessment used the Annual Farm Survey conducted by the Australian Bureau of Agricultural and Resource Economics between 1996/97 and 1998/99. Farm area has a marked effect on income from the farming operation, with larger farm businesses generally being more profitable than smaller ones. Small farms tend to be in less remote areas, however, and on average have much higher off-farm incomes.

Remoteness and other community indicators

Degree of accessibility/remoteness (ARIA) (1996)

It is calculated for each of 11 338 population centres using a weighted index of each centre's road distance to service centres in four categories (a different calculation method is used for off-shore islands to reflect water barriers). The data are summarised using statistics from the 1996/97 housing and population census conducted by the Australian Bureau of Statistics.

Social capital; degree of socio-economic advantage (1996/97)

The index is derived from census statistics (e.g.income, educational attainment, employment and job skill levels). The index takes all adults into account and covers all areas of rural Australia except centres with a population of 1000 or more. The data are interpreted from the 1996/97 housing and population census conducted by the Australian Bureau of Statistics.

Farm financial characteristics

Off-farm employment income (1996/97, 1997/98 and 1998/99)

Income from off-farm wages and salaries, other businesses, investments and government assistance payments is included. These data were obtained from the Annual Farm Survey conducted by the Australian Bureau of Agricultural and Resource Economics.

Total farm income (1996/97, 1997/98 and 1998/99)

Income from all sources (both on-farm and off-farm), not only farming returns, is included. These data were obtained from the Annual Farm Survey conducted by the Australian Bureau of Agricultural and Resource Economics.

Annual farm cash income (1996)

Farm family income includes income from all sources earned by all members of the family living on-farm, including government social service and exceptional circumstances payments. These data were obtained from the Annual Farm Survey conducted by the Australian Bureau of Agricultural and Resource Economics.

Regionalised profit at full equity (1996/97 and 1998/99)

This is defined as farm business profit and rent, interest and finance lease payments, less depreciation on leased items. It measures return on all resources used in the farm business. These data were obtained from the Annual Farm Survey conducted by the Australian Bureau of Agricultural and Resource Economics between 1996/97 and 1998/99.

Total household expenditure (1998/99)

Median total household expenditure is related to annual family income (on- and off-farm) and reflects the disposable income of farm families. These data were obtained from the Annual Farm Survey conducted by the Australian Bureau of Agricultural and Resource Economics.

Level of farm debt (1996/97 to 1998/99)

Farm debt includes all liabilities related to the farm business which appear on balance sheets in financial accounts, including the farm mortgage, other term loans, business overdrafts, fully drawn advances, amounts owed to creditors and hire purchases related to the farm enterprise. These data were obtained from the Annual Farm Survey conducted by the Australian Bureau of Agricultural and Resource Economics.

Farm equity ratio (1996/97 to 1998/99)

The farm equity ratio is calculated as farm business equity as a percentage of owned (total) capital. These data were obtained from the Annual Farm Survey conducted by the Australian Bureau of Agricultural and Resource Economics between 1996/97 to 1998/99.

Sustainable practice

Property management plan (1996/97 to 1998/99)

Developing a farm plan or property management plan could indicate that farmers or farm families are adopting an informed and professional approach to the farm business and consider long-term planning.

Proportion of farms undertaking Landcare related work (1998/99)

Percentages of farms carrying out Landcare-related work might be expected to be related to Landcare membership and reflect farmers' willingness to address land degradation problems.

Cropping management practices (1998/99)

Data depicted relate only to cropping practices, not to other types of farming and hence are relevant mainly to farmers in the wheat-sheep zone, not pastoral or intensive agriculture areas.

Indicators of rural structural adjustment

Farm establishment area (1996/97)

Change in the number of farm establishments is an outcome of the aggregation or disaggregation of farm establishments and the associated extinction or creation of farms.

Occupation as agriculture (1986, 1996)

Occupation farming (1986, 1991, 1996)

Farm family income (1986, 1991, 1996)

Average farm family income (1986-96)

Farm family income > $50 000, > $20 000, $20 000 - $50 000

Off-farm income has risen consistently in broad acre agriculture over the past 20 years from $6 000 to $20 000. During 1994/95, farm income comprised only 37% of farm family income on broadacre farms. Off-farm income has not risen nearly as far in the dairy industry.

Estimated value of agricultural operations (1986, 1996)

Estimated value of agricultural operations
>$5 000 (1986, 1996)

Estimated value of agricultural operations
>$30 000 (1986, 1996)

Estimated value of agricultural operations
>$300 000 (1986, 1996)

Increasing farm scale is seen as important for the maintenance of agricultural competitiveness. One of the most fundamental aspects in the pursuit of improved economies of scale in dryland farming operations is the amalgamation of existing properties to increase the gross value of production from the average farming unit. A temporary rise in average estimated value of agricultural operations during the early 1990s was driven by changed commodity prices.

Farm families (1986, 1991, 1996)

Families in farm establishments (1986, 1996)

The ratio of farm families to farm establishments is calculated in a statistical local area as an indication of the relative frequency of significant off-farm work commitment. This ratio also indicates areas where 'retirement' farming is concentrated along the coastal fringes and in peri-urban areas. Retirement farming is characterised by farmers who have retired from non-farm employment and have taken up farming, often with significant off-farm income through investments

Entry to farming (1986-1991, 1991-1996)

Entry to farming < 35 years old (1986-1991, 1991-1996)

Entry to farming >= 55 years old (1986-1991, 1991-1996)

The decision to enter or not enter agriculture has a major impact on the restructuring of agricultural holdings, either initiating investment in farm build up, or alternatively signalling the possibility of land sale and retirement from agriculture for the next generation. Entry to agriculture is also seen as a source of significant new skills and capital to agriculture.

Exit from farming (1986-1991, 1991-1996)

The number of farms in Australian agriculture has declined by 1.3% each year over the past few decades.

Farmer age 1986, 1991, 1996

Farmer age (2001, 2006, 2011, 2016, 2021)—fast and slow projections

The decline in the rate of entry of younger people to farming and the associated deferral of retirement from farming can be expected to lead to an ageing of the farm population. The ageing of the farm population has been evident in official statistics in Australia since 1981. This ageing has implications for both the process of agricultural structural change and the provisions of human services in rural areas. The projection data were derived from trends in the farmer age and are presented as whole of Australia graphs.

Farm numbers (2001, 2006, 2011, 2016, 2021)—fast and slow projections

Social and institutional contact as sources of change

Membership of Landcare (1998/99)

Length of Landcare membership (longest serving member on farm property) (1998/99)

Median length of Landcare membership (1998/99)

Involvement with Landcare influenced farm decisions (1998/99)

The community Landcare movement, which began in Victoria in 1986, has been very successful and it is estimated that 37% of broadacre and dairy farms in Australia had a family member who belonged to a Landcare group in 1998/99.

Resource accounts—the economic dimension of natural resource management: returns to the resource base

Gross revenue from agriculture (1996/97)

Data were modelled on a 1 km by 1 km grid using the national land use map (linked at a commodity level to the Australian Bureau of Statistics 1996/97 agricultural census). Gross revenue is measured as annual value of economic operations exceeding $22 000. Data on gross income, costs and net returns from agriculture in Australia are available from the Australian Bureau of Agricultural and Resource Economics and the Australia Bureau of Statistics.

Farm land values (1992/93 to 1996/97)

The productive value of land is the value that reflects the return to land and water resources from current production activities.

Profit at full equity from agriculture (1996/97, five-year average)

Area contributing to 80% of profit at full equity from agriculture (1996/97)

Data were modelled on a 1 km by 1 km grid using the national land use map. Economic returns to natural resource base from agriculture can be measured using profit at full equity. This is the return to land, capital and management after the value of labour provided by managers has been deducted. It does not include any debt payments to financial institutions. In 1996/97, the total profit at full equity was approximately $6555 m for the nation. Over the five-year period from 1992/93 to 1996/97, profit at full equity averaged $7530 m each year.

Government support to agriculture (1996-1997, five-year average)

Data were modelled on an industry and regional basis into the 1 km by 1 km grid using the national land use map. These regional data are indicative only. For the 1996/97 financial year the average annual cost of agricultural protection was $2211 m. A producer subsidy equivalent is the amount of money, which, if given as a cash payment in an unprotected economy, would produce an income effect equivalent to that produced by the protection.

Net economic return from agriculture (1996/97, five-year average)

Data were modelled on a 1 km by 1 km grid using the national land use map. Profit at full equity minus government support was measured in $ per hectare over a five-year average.

Costs to agriculture

Relative yield: acidity, salinity, sodicity, aggregate

The data have been aggregated to align and link with the 1 km by 1 km grid using the national land use map. Relative yield is measured as a percentage and equals the actual yield, as currently recorded, divided by the potential yield that would occur if the soil constraint(s) were not present.

Gross benefit from remediating: acidity, salinity, sodicity, aggregate

The data have been aggregated to align and link with 1 km by 1 km grid using the national land use map. Gross benefit ($ per hectare per year) equals profit at full equity attainable without the soil constraint, less the profit at full equity attainable under current conditions. It can be thought of as the dollar value of the yield gap (caused by the soil constraint).

Impact cost of salinity (2000, 2020)

The data have been aggregated to align and link with the 1 km by 1 km grid using the national land use map. Impact costs result from marginal increases in soil constraints from 2000 to 2020. Impact costs are calculated for salinity as this is the only soil constraint with the required time series data.

Maximum net present value attainable from lime and/or gypsum application

Highest returning soil treatment: lime, lime and gypsum, gypsum

Data present maximum net present value ($ per hectare) attainable from lime and/or gypsum application to manage soil acidity and sodicity. Data were derived from the Australian Soil Resources Information System. These data were aggregated to align and link with the 1 km by 1km grid using the national land use map (linked to the profit at full equity surfaces). Net present value is equal to the time-discounted benefits minus the time-discounted costs. Net present values show that additional soil treatment by farmers is financially worthwhile for around only four percent of agricultural land.

Costs to non-agricultural infrastructure

Downstream costs: salinity, turbidity, erosion and sedimentation, aggregate (2000)

Data were derived from the Australian Agriculture Assessment 2001 (NLWRA 2001d) and Australian Water Resources Assessment 2000 (NLWRA 2001a). These data were already aggregated to river basins. Downstream or ex situ impacts are defined as phenomena that occur away from the original source of the impact. This typically occurs because the problem arises only after a water supply is contaminated (e.g. cost of boiler corrosion in a city factory several hundred kilometres from the place where salt entered the river supplying water to the city). Downstream costs include the impact of salt in water used in urban areas, water turbidity costs and sedimentation costs.

Local impact costs from salinity and rising watertables (2000, 2020, increase 2000 to 2020)

These data were derived from the Australian Dryland Salinity Assessment 2000 (NLWRA 2001b) at varying scales from 1:1 000 000 to 1:250 000, then aggregated to align with the 1km by 1 km grid of the national land use map. Local or in situ impacts are defined as those that occur in local association with land degradation processes (e.g. the impacts of rising groundwater on infrastructure are treated as local impacts. Local costs include damage to roads, bridges and houses).

Rangelands

Social and economic information

Social and economic information products available for rangelands areas include:

All of the data are summarised by Australian biogeographic regions (version 5.1)

Coverage

Rangeland areas of Australia.

Season quality in the rangelands

Data from weather satellites can be used to estimate the response of vegetation to rainfall, using the normalised difference vegetation index. The normalised difference vegetation index provides an estimate of the vegetation greenness. Data are compiled every two weeks throughout the year and give continental coverage across Australia. The spatial resolution of the data is 1km by 1 km.

Comparing each area to itself over time gives a good indication of relative changes in herbage. A relative rating of season quality can be mapped by comparing a particular year with all years recorded.

Coverage

Land tenure in the rangelands from 1957 (1:1 000 000)

The maps are believed to be the best and in some cases, the only digital historical catalogue of land tenure for Australia's rangelands.

These maps are only intended to illustrate broadscale changes in land tenure across Australia's rangelands. Their application is not intended for accurate cadastre or administrative boundary documentation or analyses.

Coverage

Rangeland areas of Australia.

Total grazing pressure from 1957 in the rangelands

A series of maps illustrating the total grazing pressure by statistical local areas for rangeland areas in Australian for each decade since the 1950s. Maps are available of estimates by statistical local area of the density of macropods, goats, rabbits, sheep and cattle.

Coverage

Rangeland areas of Australia.

Water

Surface water management area boundaries (1:250 000)

Surface water management areas are regions defined by State and Territory water management agencies for use in national water resources reporting.

Many surface water management areas are the same as the river basin boundaries defined by the Australian Water Resources Council. In some States and Territories, however, some surface water management areas are a subset of these river basins.

Groundwater management unit boundaries (1:250 000)

A nested set of catchments and subcatchments for Australia

The catchments have been determined from Version 2 of the 9-second continental digital elevation model produced by the Centre for Resource and Environmental Studies at the Australian National University, for the Australian Surveying and Land Information Group.

The grid of subcatchments and catchments are supplied with an associated attribute table defining the subcatchments according to four minimum area thresholds (2.5 km2, 25 km2, 50km2 and 500 km2).

Estimated daily and monthly streamflow data from 1901 to 1998 for 286 catchments in Australia

The long time series of streamflow data are important for both research and management of Australia's hydrological and ecological systems.

A daily rainfall/run-off model was used to extend the streamflow data. The model estimates streamflow from daily rainfall and areal potential evapotranspiration data. The parameters in the model are first calibrated against the available historical streamflow data. They are then used to estimate monthly streamflow from 1901-1998.

The modelling is carried out on 331 catchments across Australia, most of them located in the more populated and agriculturally important areas in eastern and south-east Australia. These catchments have at least ten years of streamflow data and catchment areas between 50 km2 and 2000 km2.

1985 review of Australia's water resources and water use

Australian Water Resources Assessment 2000

These attributes are linked to spatial boundaries for 325 surface water management areas and 535 groundwater management units in Australia. Many of these attributes are also aggregated to a national, State and Territory, groundwater province and river basin level.

Major water resources infrastructure

(part of the Australian Water Resources Assessment 2000 database)

Surface water gauging stations

(part of the Australian Water Resources Assessment 2000 database)

These locations and attributes were entered into a database by each State and Territory to define the location of gauging stations.

Surface water quality

Exceedance and trend analyses are available for monitoring stations. Attributes include total phosphorus, total nitrogen, nutrients, pH, turbidity, salinity (electrical conductivity).