Resource information
A soil survey and mapping program financed by the municipality of Gazi located on the north–central part of Crete was carried out. The studied area is characterized by a moist meso-Mediterranean climate and different degrees of land degradation from human activities. Surface soil horizons are eroded, resulting in fertility decline for olive trees, the dominant crop. According to the U.S. Department of Agriculture classification, the soils at higher altitudes are classified as Entisols xerorthents and those at lower altitudes as E. xerofluvents. Using a geographical information system (GIS), all spatial data from the soil survey were organized to facilitate its storage, management, and analysis. Based on topographic–geological maps and aerial photographs, other derivative data layers were calculated. Sampling points were determined using GIS. This information, and all results pertaining to the sample, was entered into a graphical database, designed to store all relevant data for each point. Data layers describing the spatial distribution of key parameters such as soil texture, pH, CaCO₃, and nutrient status were produced using geostatistical methods. Soil classification and the evaluation of soil suitability for various activities were greatly facilitated by visualization of the data as various thematic maps. Our study demonstrates the ability of GIS as an administrative tool that can assist farmers in improving farming practices.
