Geomatics based soil mapping and degradation risk assessment of the cultivated land in El-Fayoum Depression, Egypt [electronic resource].

Includes references.

Geomatics technique was used in this study for producing physiographic - soil map of El-Fayoum Depression at large scale (1:250,000). Landsat ETM images and digital elevation model (OEM) are used in ENVI 4.2 software to produce the physiographic map of the studied area at the landform level. The obtained map shows that the area comprises three distinct landscapes; i.e., alluvial plain (12.22%), fluvio-lacustrine plain (34.20%) and lacustrine plain (53.58%). The terraces of various origin and elevation are the main landforms (64.99% of the total area), while the overflow and decantation basins represent the rest of the area. The soils were classified to the sub-great group level on the basis of the Key to Soil Taxonomy. The correlations between the physiographic and taxonomic units were designed in order to produce the map of physiography and soils. The different soil units were represented by 16 soil profiles and 5 I disturbed soil samples were collected and analyzed. The results were used for assessing the degradation hazard according to F AO guidelines. The hazard of each type was defined as low, moderate, high, and very high. The obtained data show that salinity, alkalinity and water logging are the main encountered degradation hazard. Values such as EC, ESP, and ground water level could reach 16.33 dS/m, 31.05 % and 40 cm respectively. These results will be of great help and basic sources for the planners and decision makers in sustainable planning.

Summary in Arabic.

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