للكاتبين
*Ali said;** Ali Eliawa
*Civil Eng. Dept., Faculty of Eng., El-fateh University, Tripoli, Libya,
**Libyan Centre of Remote Sensing and Space Science, Tripoli, Libya
Abstract
The use of satellite images in monitoring the natural phenomena increase during these years because of
the amount of information that can be gained from it. Costal Hazard (erosion and accretion) one of these
phenomena that can be monitored with it.
The change of climate is responsible of global warming, which leads to the Sea Level Rise (SLR) and
increase the speeds of the wind. The wave energy is derived from wind which creates wave refraction
along a straight shore line that causes coastal hazards (erosion and accretion).
This paper presents the work done to study the changes of the geomorphology of the beaches of Gulf of
Sidra and borders with the Mediterranean Sea in the north using LandSat image and topographical map.
The study area has a coastline of 268 km in length. It used for settlements, oil refinery plant and harbour.
The people live in this area is about 190397 (report 2005).
Analysis of coastal change shows that from 1965 to 1987 both accretion and erosion took place having a
balance of land area. But 1987 to 2000 erosion was the main process taken place in the coastal area.
Introduction
In this assignment, and in the absence of an accepted methodology for building long-term scenarios, we
can follow the approach suggested by R. Gommes and J.du Guerny (FAO, 1998) concerning the analysis
of population statistics in relation to a national Vulnerability Index based on physiographic features and
population density. The vulnerability of the coastal population, infrastructure and agriculture to enhanced
sea level rise- if considered at a global scale – varies considerably, over several orders of magnitude.
Gommes and du Guerny have developed some crude indicators in their article. They have developed the
"Insularity Index" of whole countries or regions as the ratio between the length of the coastline (km) and
the total land area (km2).