GIS-based soil maps as tools to evaluate land capability and suitability in a coastal reclaimed area (Ravenna, northern Italy)

Abstract

Land capability and suitability maps are useful tools for soil resource conservation. This study aimed to build land capability and suitability maps using a multi-thematic approach by GIS in a salt-affected coastal area of Italy. Topographic, morphological, geological, pedological delineations and land cover maps, remote sensing image and climate data were acquired and the main physical and chemical properties, including electrical conductivity (EC) and available water capacity, were analysed on the soil samples collected in the study area. The acquired information were elaborated through QGIS software to obtain the land capability and suitability maps. The suitability map showed that most of the area (80%) is suitable for cultivation and, therefore, can be addressed for agricultural purposes without risk of degradation. In fact, the land capability map showed that 42% of the investigated area belongs to class I and II indicating that they can be used for a wide range of cultivations. While 44% of the investigated area clustered in class III and IV. In these latter the cultivation should be allowed to a limited range of crops due to the high sand content, which does not allow a good water retention, and due to a strong intrusion of sea water with consequent increase of the soil EC. In our study area, where agricultural productivity and environmental impact are in conflict, to classify the lands on base the land capability and suitability could help to define the best agricultural practices to apply in order to preserve soil functions.

Keywords

• Agricultural lands
• Salt affected soils
• Geographic information system
• Land capability map
• Land suitability map