Qualitative and Quantitative Assessment of Land Degradation and Desertification in Egypt Based on Satellite Remote Sensing: Urbanization, Salinization and Wind Erosion

Abstract

This chapter analyzes, generally, the problems of desertification and land degradation, highlighting the difference between the two terms and aspects to be assessed. The common land degradation/desertification processes, in Egypt will be highlighted, however the current chapter, as a start of an articles series focusing on desertification, will only consider three important processes (i.e. urban encroachment, salinization and wind erosion) to be detailed studied. Both the descriptive and quantitative approaches will be followed and merged, showing advantages of combining both approaches in assessment, sizing and combating preparedness. Regional assessment scale for the whole territory of Egypt, in addition to some detailed case studies will be introduced, with adaptation of indicators scale. Remote sensing, in addition to thematic maps, may supply valuable information concerning landscape features, vegetation type and quality and land use/cover, as inputs of the FAO-UNEP provisional methodology to assess aspects of different desertification processes. Multi scale and multi spectral satellite sensors supply reliable data sources to point out variable indicators needed to evaluate the present status and risk of different degradation/desertification processes. Multi temporal satellite imageries and thematic data make it possible to detect temporal land use/cover changes, hence compute the annual rate of a desertification process. The EU-MEDLUS methodology assessing the environmental sensitivity to desertification is rather due to the use of remote sensing data in computing the Soil Quality Index (SQI), Vegetation Quality Index (VQI), and Management Quality Index (MQI). Climate Quality Index (CQI) may be computed, using meteorology satellites data. The Geographic Information System (GIS) is a valuable tool to store, retrieve, update and manipulate the huge amount of data needed to map aspects if each desertification process. The system also facilitates computation and mapping environmental parameters of different quality indices, hence determining Desertification Sensitivity Areas (DSA’s). The Egyptian territory is susceptible to very high-to-high desertification sensitivity. However the Nile Valley is moderately sensitive due to cultivated vegetation cover. Combating desertification measures are essential for the sustainable agriculture. Special concerns have to taken at the desert oases, wadis and interference zone due to their rule in decreasing food gaps and accelerating agriculture expansion. Operational innovative monitoring is recommended to an early control of desertification sensitivity. Defining and followup the Environmentally Sensitive Areas (ESA’s) are needed to point out the risk, magnitude and causes of land degradation and desertification processes. Combining both descriptive and quantitative desertification approaches may grantee full sizing of desertification impacts.