استفاده از یک روش مبتنی بر GIS برای تهیه نقشه و سنجیدن مناسب بودن زمین

ABSTRACT Mapping and evaluating land suitability using a GIS-based model

Agriculture is one of the largest sectors of the Egyptian economy and provides 20% of gross domestic product, 34% of the total exports and employs 32% of the total labor force (CAPMAS, 2012). Land resources in Egypt face pressures from continuing land degradation and increasing number of people. The population in Egypt is growing very rapidly as its density has doubled during the last three decades (Hamza and Mason, 2004). Therefore, the efficient management of natural resources in Egypt is essential for ensuring food supplies and sustainability in agricultural development.
In order to manage land resources properly, land suitability assessment is often conducted to determine which type of land use is most appropriate for a particular location (Bodaghabadi et al., 2015). Land suitability analysis is a method of land evaluation, which allows identifying the main limiting factors of a particular crop production (Halder, 2013). At the same time it enables decision makers to develop a crop management system for increasing land productivity (Chen, 2014).
Land suitability assessment is a planning approach to avoid environmental conflicts by the segregation of competing land uses (FAO, 1976; Rossiter, 1990; FAO, 1991; Al-Mashreki et al., 2011; Ashraf and
Normohammadan, 2011). Land suitability evaluation can be either qualitative or quantitative. Qualitative approach is used to assess land potential on a broad scale and the results are given in qualitative terms. Quantitative approach involves more detailed land attributes by using parametric techniques which allow various statistical analyses to be performed. The land suitability evaluation procedure in the quantitative approaches involves many simulation modeling systems (Van de Graaff, 1988; Shields et al., 1996) to quantify the potential of land for specific uses. FAO guidelines on land evaluation system (FAO, 1976 &1985) and physical land evaluation methods (Sys et al., 1991) were widely used for land suitability assessment.
Remote sensing and Geographic Information Systems (GIS) hold great promises for improving the convenience and accuracy of spatial data, more productive analysis and improved data access. These technologies have been used to assess the criteria required to define the suitability of land (Booty et al., 2001; De la Rosa and Van Diepen, 2002; Darwish et al., 2006; Mokarram et al., 2010; El Baroudy, 2011; Hamzeh et al., 2014; Mishelia and Zirra, 2015) and were also adopted for the present study