Remote sensing and GIS in modeling visual landscape change: a case study of the northwestern arid coast of Egypt

Land use planners in many countries have recognized the importance of the aesthetic values of landscape. Their desire to incorporate these values into decision-making processes has created a need to identify valid ways to quantify the scenic characteristics of landscapes. This has led to an increasing interest in the use of spatial data and geographic information systems (GIS) methodology in assessing visual attributes of the landscape. The objective of the present study is to assess the visual changes in a rapidly developing coastal area of Egypt using remotely sensed data (satellite images and aerial photographs) and raster GIS modeling. The analysis assesses changes between a period characterized by a vernacular, relatively natural landscape (1950s) and the beginning of the exploitation of the region for resorts (1990s). Using land use/land cover classes extracted from the satellite images and aerial photographs, four visual attributes of landscape are identified: land use/land cover diversity, activity (degree of naturalness), proximity to the shoreline, and topographic variety. A composite index is also developed. Although these attributes and the composite index rely mostly on the type of land use/land cover information on the landscape under consideration, the adopted techniques succeed in detecting several changes in the attributes, spatially locating them and mapping the magnitude of their changes. This study demonstrates what can be done to analyze and assess what is usually considered an incommensurable resource, the visual attributes of landscapes. It also reveals the extent of the impact of unplanned or ill-planned activities on one of the fragile resources of arid landscapes.