Located on the northwest tip of the island of Java, the city of Jakarta looks out over the Java Sea. Like many urban areas all over the world, Jakarta, Indonesia, is growing. Since 1976, the population has more than doubled. More people require more housing, more stores, and more streets. This urban growth means that surrounding, undeveloped land has been transformed.
This time series of images shows the growth of the city between 1976, when the population was 6 million, and 1989, when the population was 9 million, and 2004, when the population was 13 million. The images use satellite observations of visible and infrared light reflected by the Earth's surface to enhance the contrast between land surface types. Vegetation, which reflects infrared light very strongly, appears red, and urban areas appear light green. Each image in this series covers an area of 49 by 49 kilometers and is centered near 6.2 degrees South latitude, 106.8 degrees East longitude.
In the 1976 image, captured by the Landsat MSS scanner, the city makes a green patch in image center and along the coastline, while the surrounding area shows large areas of remaining vegetation (red). The city spread considerably to the east by 1989, when a subsequent Landsat mission captured the middle image in this series. By 2004, when the final image was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite, westward expansion had occurred as well. Nearly the whole scene appears in the green of urban development, with few pockets of vegetation remaining.
For the past few decades, Africans have been moving from rural areas into cities, seeking work. The continent’s urban population has skyrocketed. Nairobi is a prime example of that migration, with its population pushing upward and its boundaries pushing outward.