Site mapping techniques for agricultural land
D.D. Fraser and G.P. Ellis
Land use planning division
Department of land information
Royal Melbourne of Technology (RMIT)
Melbourne Austria
Introdouction
Whole farm planning may be described as the considerations of the total assets from the farm the soil water trees stock pastures crops and wild life and how to make the best use of them
To efficiency manage a farm it is necessary to consider the whole area including areas surroundings the farm and to take in to account natural boundaries.
In the making maps produced by analogue means have been used by land managers in a mostly quantitative manner. To assists in decision making.
Computer technology has enabled analogue information to be converted in to a spatial form digital data and appreciate software has resulted in quantitative analysis ..The major limitation of using modern technology in whole farm planning however is the significant expense of collecting the original data at a suitably large scale .
This paper will back look at some of the ways in which exciting data such as maps and aerials photographs .Along with field data can be overplayed enhanced and analyzed using computer assisted techniques.
Main considerations
In the process of preparing plans for agricultural units a number of factors are taken inn to account of these assisted techniques.
-
Variability with regard to scale and accuracy of source information:
In preparing a base map at a suitably large scale already existing information is typically accessed .The problem is that this information has been collected in many different ways and at any levels of accuracy some information for example precipitation may be levels of accuracy may be gathered at a regional level where as other information for example the positions of fence lines is known quite precisely the requirements isda successfully amalgamate and merge these various data sets.
- The smallness of the area to be covered
When the area be managed is relatively small as is often the case then it is likely that existing information at a suitably large scale and with sufficient accuracy not be available .This may necessaries the collection of the required data by way of a field work program .
In Australia the largest scale topographic mapping available is 1:250000 because of the graphic limitation of this scale map much detail is not shown that which is displayed is every generalized.
- The cost of producing understandable and relevant base maps
Field work programs are quite often expensive to property carry out one way of cheaply and effectively producing base maps which carry useful information the purpose of agricultural management is to utilize over lapping aerial photography.
- Temporal aspect of agricultural land
Agricultural land does not remain the some over long periods of time consequently and maps to be used for planning purposes must be systematically up graded with time so that they reflect the current or perhaps future state of the land rather than a past and obsolete view.
- Interactions between natural and man made systems
In determinations the suitability of land for a particular use and the subsequent monitoring of the land for effective utilizations account must be taken of the interaction between the natural and man made systems .If nature is ignored inappropriate land use can result and this may lead to significant problems such as land degradation for example if step hills are cleared of vegetation a resultant rise in the water able may cause. Problem elsewhere.
To assist in the solution of the difficulites outlined above it is suggested that the collect or convert data so that it is digital and to analyze the digital using computer technology is sensible procedure to follow.
