Validity of Geographic Information Systems (GIS) applied to protected cultivations

Any kind of protected cultivation plan which concerns irrigation, electrification, methane pipe-lines, structures modernizing, roads conditions, etc, presumes the knowledge of the compartment. This paper describes the investigation by means of an advanced GIS (Geographic Information Systems) technology on greenhouses distribution and dimension. GIS is a data base management system (DBMS) specifically designed for simultaneous processing of spatial and related attribute data. GIS technology has been applied in an area extending 3,588 ha located in the northern side of the town of Marsala (western Sicily, Italy). This work consists of three main steps: i) The first step includes the digital acquisition of base maps (aerial photographs made in 1994 and updated in 1998). On the georeferenced digital images, 2,607 greenhouses have been individuated and reported. This has allowed to estimate the size of each greenhouse. ii) The second step consists of field observation. Two operative teams have been formed to acquire data about greenhouse structures (e.g. size, shape, type of material), kind of cultivations, farm-management and so on. A comparison between measured and estimated greenhouses size has revealed a less than 2-3% difference iii) The third step includes the construction of a database containing all the acquired information. Computer program ARCVIEW-GIS has been used to elaborate simultaneously both the geographic spatial data and related attribute data. This has made it possible to produce a combination of maps and tables that answer any question about spatial and numerical distribution of the acquired information on protected cultivations. GIS method applied to protected cultivation has given sufficiently confident elements to create updated cartographies with a perfect localization of greenhouse structures and precise indication of their dimensions. This method also consents to discern heights and construction peculiarities. This cartography proves to be absolutely necessary for an eventual next research into territory. The use of this program, makes the organization and the management of an enormous amount of collected data easy and fast.