Aerial photography used in new agricultural survey

The National Statistics Office has carried out a comprehensive survey combining airborne digital photography with data collected on land to provide an identikit of the agricultural scene in Malta and Gozo, as well other important data.

The survey provides data on the structure of agricultural land, such as irrigated land, dry land, and garigue land as well as on areas with vineyards and fruit trees.

Alfred Camilleri, director general of the NSO, said that through the exercise, the NSO was at the forefront of other countries regarding the use of remote sensing techniques for statistical purposes.

This new technology has in Malta's case been used to cover the whole country.

Malta's size was an advantage because in other countries such sensing was only carried out on a sample basis because of the vastness of land involved, he said.

"It is the most exhaustive and comprehensive up-to-date statistics exercise ever carried out," Mario Vella, head of the Agriculture and Fisheries Unit of the NSO, said.

The survey, the first time that such modern technology has been used for the collection of statistics, provided the NSO with very useful information.

Comprehensive, reliable and timely information on agricultural resources is very necessary for any administration for planning purposes.

Remote sensing techniques will continue to be used to acquire agricultural data, Mr Vella said.

All the information is available to local councils.

The last published census of agriculture was carried out in 1983/84 and since then the NSO relied on marketing data recorded from the Pitkali and the Farmers Co-op.

However, not all crops go through the markets, including potatoes for export, grapes for the wine industry, tomatoes for processing and all forage.

Mr Vella said the NSO commissioned the Euro-Mediterranean Centre on Insular Coastal Dynamics (ICoD) of the Foundation for International Studies to conduct the survey which on its part engaged Captain Ray Zarb of the European Flight Academy to take the aerial photographs.

Concurrently with the aerial photographs, NSO staff, together with ICoD personnel, embarked on a 'ground truthing' exercise of 132 hectares in order to come up with a solid assessment of the actual crops on the ground.

Mr Vella said this was of extreme help in the interpretation of the data shown in the photographs.

A number of large areas, including the Burmarrad basin, Dwejra, the Pwales basin, Ghaxaq, Rabat, and Siggiewi were physically surveyed.

As the aerial photography was completed, all the collected data were indexed and archived and the photographs interpreted. Although the analysis was computerised, it was nonetheless labour intensive as it involved photo interpretation, Mr Vella said.

An agricultural census was held in October 2001 and the data from both sets were correlated.

He said that the differences in the results from the two separate sources - aerial photography and the data from the census - were negligible.

The extent of agricultural land established by the aerial photography project, that is land under vine and orchards, irrigated land, dry land, and area under fodder, proved to be comparable with the figure yielded by the census carried out in 2001, Mr Vella said.

Mr Vella said the aerial photographs were taken in April 2001 after consultation with the Agriculture Department. This was considered to be the prime time as far as forage was concerned as this crop would be fully grown and nearing harvest.

Mr Vella said that apart from the crops, the NSO also wanted to know about the structure of the agricultural set-up including manpower, who was on part-time and on full-time basis, what machinery was used and other factors. The ground census of agriculture was held in October 2001.

The aerial photographs also established where irrigated land and dry land were situated, and showed product by product in the various localities.

Apart from agriculture, the exercise provides useful information on rural and urban areas, such as the built-up areas and boundaries of local councils.

The full set of photographs, which are the latest complete set, are available against payment.

In fact the NSO has already had requests from third parties to obtain copies of land use in Malta.

Among the users who will benefit directly from the project, apart from local councils, are secondary and university students as well as government departments and institutions.

Information about the photographs is available on the NSO's website.

www.nso.gov.mt

nso@gov.mt