1 This publication presents results from the ABS Water Survey - Agriculture 2002-03 which was conducted as a supplement to the Agricultural Survey 2002-03.
SCOPE AND COVERAGE
2 The scope of the Agricultural Survey 2002-03 is establishments undertaking agricultural activity with an estimated value of agricultural operations (EVAO) of $5,000 or more.
3 For the Agricultural Survey 2001-02, a stratified random sample of 35,000 farms was selected. For the Agricultural Survey 2002-03, a sub-sample of 28,000 units from the 2001-02 selections was used. This helped control the estimates of movement for that year which was particularly important given the impact of the drought.
4 The Water Survey - Agriculture 2002-03 was targeted at the reference population of farm establishments which answered yes to the question, 'Did you irrigate between 1 July 2002 and 30 June 2003?', in the Agricultural Survey 2002-03. In addition, large units which did not respond to the question were included. The survey results in this publication are based on a sample of approximately 8,000 farm establishments and the results have been weighted to cover the full reference population. Estimates were adjusted for errors in response to the trigger question. A response rate of 91% was achieved.
5 A number of agricultural establishments hold water entitlements that are not included in the estimates presented in this publication. These include entitlements used for other agricultural practices, eg. stock watering, dairy wash-down and produce cleaning, establishments that did not irrigate during the reference period and establishments with an EVAO of less than $5,000. These establishments fall outside the scope of this survey.
6 The unit for which statistics were reported in the survey was the establishment unit. For the Water Survey - Agriculture 2002-03, the concept of an establishment is the same as that used in the Agricultural Census and the Agricultural Survey. An agricultural establishment is the smallest accounting unit within a State or Territory controlling its productive activities and maintaining a specified range of detailed data enabling value-added to be calculated. In general an establishment covers all operations at a physical location, but may consist of a group of locations provided they are within the same Statistical Local Area (SLA) or contiguous SLAs. The majority of agricultural establishments operate at one location only.
7 Data contained in the tables in this publication relate to agricultural businesses within the survey scope (see paragraph 2), which operated in Australia at any time during the year ended June 2003.
8 Data related to the number of agricultural establishments, the total area of agricultural land and the area of land planted to crops was collected in the Agricultural Survey 2002-03 and the Vineyards Survey 2003.
COMPARABILITY WITH ADDITIONAL DATA
9 Some estimates of irrigating agricultural establishments and area of crop irrigated presented in this publication are higher than the estimates of total agricultural establishments and area of land planted to that crop. Analysis has shown this has arisen due to issues associated with the comparison of data sourced from three separate collections. Each of these three collections is subject to both sampling error and non-sampling errors (such as reporting errors and non-response). Several measures have been implemented to minimise the discrepancies, including extensive data editing, follow up with respondents to verify reported values and adjustments for non-response. For further information please contact the Director, Environment and Energy Business Statistics Centre, on (03) 6222 5804.
COMPARABILITY WITH WATER ACCOUNT
10 Estimates of water usage presented in this publication differ from those presented in the Water Account Australia 2000-01 (cat. no. 4610.0). Estimates from the Water Survey - Agriculture 2002-03 represent only water used for the irrigation of pastures and crops during the reference period as reported by irrigating agricultural establishments. Estimates of water usage presented in the Water Account represent water used for all agricultural purposes. For the Water Account, water use was determined by applying regional water application rates, obtained from water supplier surveys and state and territory or industry contacts, to the area of irrigated crops and livestock numbers. For further information please contact the Director, Centre of Environment and Energy Statistics, on (02) 6252 7348.
11 Units in the Water Survey - Agriculture 2002-03 have been classified according to the methodology described in Australian and New Zealand Standard Industrial Classification (ANZSIC) (cat. no. 1292.0).
RELIABILITY OF DATA
12 The estimates in this publication are subject to sampling and non-sampling errors.
13 The estimates in this publication are based on information obtained from a sample drawn from the total farm population in scope of the collection, and are subject to sampling variability; that is, they may differ from figures that would have been produced if all farms had been included in the survey. One measure of the likely difference is given by the standard error (SE), which indicates the extent to which an estimate might have varied by chance because only a sample of units was included. There are about two chances in three that a sample estimate will differ by less than one SE from the figure that would have been obtained if a census had been conducted, and approximately nineteen chances in twenty that the difference will be less than two SEs.
14 In this publication, 'sampling' variability of the estimates is measured by the relative standard error (RSE) which is obtained by expressing the SE as a percentage of the estimates to which it refers.
15 Where the RSE of an estimate included in this publication falls in the range of 10% to less than 25%, it has been annotated with the symbol '^' indicating that the estimate should be used with caution as it is subject to sampling variability too high for some purposes. Where the RSE of an estimate is 25% to 50%, it has been annotated with the symbol '*', indicating that the estimate should be used with caution as it is subject to sampling variability too high for most practical purposes. Where the RSE of an estimate exceeds 50%, it has been annotated with the symbol '**', indicating that the sampling variability causes the estimate to be considered too unreliable for general use. Separate indication of the RSEs of all estimates is available on request.
16 The following table contains estimates of RSEs for a selection of the statistics presented in this publication.
Relative Standard Errors of Selected Estimates, By State - 2002-03
|Total area irrigated (ha)|
|Total volume applied (ML)|
|Cereal crops for grain or seed - area irrigated (ha)|
|Cereal crops for grain or seed - volume applied (ML)|
|Vegetables for human consumption - area irrigated (ha)|
|Vegetables for human consumption - volume applied (ML)|
|Nurseries cutflowers or cultivated turf - area irrigated (ha)|
|Nurseries cutflowers or cultivated turf - volume applied (ML)|
|Ongoing water entitlement - number|
|Ongoing water entitlement - volume (ML)|
|Quantity of ongoing entitlement allocated - (ML)|
|Irrigation methods - surface - area irrigated (ha)|
|Irrigation methods - sprinkler - microspray - area irrigated (ha)|
|- nil or rounded to zero (including null cells)|
|(a) Includes ACT|
17 Errors other than those due to sampling may occur because of deficiencies in the list of units from which the sample was selected, non-response, and errors in reporting by providers. Inaccuracies of this kind are referred to as non-sampling error, which may occur in any collection, whether it be a census or a sample. Every effort has been made to reduce non-sampling error to a minimum by careful design and testing of questionnaires, operating procedures and systems used to compile the statistics.
ABS DATA AVAILABLE ON REQUEST
18 As well as the statistics included in this and related publications, the ABS may have other relevant data available on request. Inquiries should be made to either the National Information and Referral Service on 1300 135 070 or Cherie Poulton on (03) 6222 5983.
19 A range of environmental and agricultural publications is produced by the ABS, including:
20 Current publications and other products released by the ABS are listed in the Catalogue of Publications and Products (cat. no. 1101.0). The Catalogue is available from any ABS office or the ABS web site. The ABS also issues a daily Release Advice on the web site which details products to be released in the week ahead.
- Water Account, Australia (cat. no. 4610.0)
- Agricultural Commodities, Australia (cat. no. 7121.0)
- Environment Expenditure Local Government (cat. no. 4611.0)
21 ABS publications draw extensively on information provided freely by individuals, businesses, governments and other organisations. Their continued cooperation is very much appreciated; without it, the wide range of statistics published by the ABS would not be available. Information received by the ABS is treated in strict confidence, as required by the Census and Statistics Act 1905.