| Summary: | 碩士 === 國立中央大學 === 國際永續發展碩士在職專班 === 102 === The main objective of this research is aimed at producing multi-temporal land cover maps of the Western Gambia in order to monitor land-cover changes (LCC) using Remote Sensing techniques with a focus on urban growth during the period 1985 – 2013. The study area is the Western Gambia covering West Coast Region and part of North Bank Region lying between Latitudes 13o 36’ N and 13o 03’ N and Longitude 16o 54’ W and 16o 06’ W. About 63.49% of the
country’s population resides here with a population density of 478 people per km2.
For this purpose, multi-temporal Landsat images for 1985, 1999, and 2013 were acquired. The existing land cover reference maps collected and modified for accuracy assessment. These multi-temporal data were processed using spatial analysis tools of geo-referencing, Support Vector Machine (SVM) classification, and post- classification processes, to map the patterns and extent of land cover in the study area as well as determine the magnitude of changes between the years of interest.
The result of the study showed that the built-up areas have been on a constant positive and mostly uncontrolled expansion from 46.42 km2 of the study area in 1985 to 97.35 km2 in 1999 and to 193.02 km2 in 2013. On the other hand, terrestrial vegetation has been on a steady decline, from 1,184.22 km2 in 1985 to 929.69 km2 in 2013, while the cultivation land experienced a slight increase in area. The mangrove forest is fairly stable in the past three decades. Population pressure is the major driving forces of LCC in the Western Gambia; therefore the government and other stakeholders should develop policies and strategies to achieve a balanced, coordinated and sustainable natural resources management.
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