Changes in land use and land cover (LULC) over time are significantly affected by human activities. The rates of changes often vary between developed and developing countries. Large-scale farming, urban development and biodiversity conservation are examples of major driving forces for LULC changes in developed countries whereas rapid population growth, economical constrictions, and poverty in developing countries. This study aimed to examine the land use and land cover changes of two cities, Beirut and Los Angeles (LA) from 1988 to 2007. Cloud-free Landsat TM tiles for both cities were acquired for the years 1988, 1999 and 2007 to detect land use changes of the study areas. Supervised classification of the Landsat imagery was performed using ERDAS Imagine software. Land uses were categorized into four classes including built-up land, green-land, wasteland, and waterbodies. Google Earth imagery was used to validate the accuracy of the classification.
The population density of Beirut in 2007 was found greater than the density of LA as demonstrated by the land consumption rate per capita of Beirut at 0.001 compared to LA at 0.025. During the study period, 1988-2007, the developing city, Beirut, experienced a rapid population growth which contributed to an increase in build-up land, 19.21%, and a decline in green-land, 25.51%. On the contrary, the population size in the developed city, LA, elevated slightly, 10% over the two decades; relatively limited alterations were identified in build-up land, 4.92%, and green-land, 1.14%. Another potential factor impacting land use distribution was the discrepancies among environmental law and policies between the two cities. Lack of proper environmental regulation provided limited protection for grassland and forested area resulting in significant conversion from green-land to build-up land in Beirut. The results of this study suggested that developing countries are likely to lose greater percentages of grassland and forested area in order to adapt into rapid economic and population growth. Environmental policies to promote sustainable development are crucial in order to prevent ecosystem degradation and habitat loss, particularly in developing countries.