Use of satellite data and GIS for soil mapping and monitoring soil productivity of the cultivated land in El-Fayoum depression, Egypt

Abstract

The aims of this study are: (1) producing a geometrically corrected physiographic–soil map scale 1:50,000 reduced to the attached map for the studied area; and (2) monitoring soil productivity of the cultivated land in El-Fayoum depression. To fulfill these aims, 16 soil profiles were chosen to represent the different mapping units. Morphological description was carried out and soil samples were collected for physical and chemical analysis. Based on ETM images analysis and the geographic information system, coupled with the field work and laboratory analysis data, the physiographic–soil map was produced. The following main landscape units can be identified: 1. alluvial plain; 2. fluvio-lacustrine plain; 3. lacustrine plain. This study is based on comparing between the data extracted from previous study carried out in 1961 by RISW report and the data resulting from the current study to monitoring soil productivity in the studied area to make comparison as well as monitoring more realistic. Soil characteristics and productivity criteria are matched for getting soil productivity in the period 1961–2010. Monitoring of soil productivity includes the following main landscapes, i.e., lacustrine plain, fluvio-lacustrine plain, and alluvial plain. The soil characteristics of previous and current study were grouped and recalculated to meet the requirements of Riquier et al. (1970) modified by FAO (2007). The results reveal that: Generally, all the studied sites in El-Fayoum depression changed positively in the productivity grade except that the soil of lacustrine plain seems to be still degradable for the reason that it receives a lot amount of drainage water from all the soil of the depression. The improvement of the soil productivity grade in the studied area due to the good quality of land management such as: – sub-soil plugging and adding organic materials to overcome soil compaction; – establish drainage network system to reduce water logging; – leaching processing to remove the excess of salinity occurs in the studied area; – gypsum addition considering gypsum requirements to reduce soil alkalinity.