April 25, 2016
From NASA Earth:
Santa Cruz, Bolivia
An astronaut aboard the International Space Station (ISS) took this photograph of the city of Santa Cruz. The city’s full name is Santa Cruz de la Sierra because it lies just east of the Andes Mountains in the hot, tropical lowlands of east-central Bolivia.
Flying at 27,600 kilometers (17,150 miles) per hour, astronauts must quickly recognize features on the ground. In this case, the eye is drawn to the gray-brown line of the Piray River and to the great patch of pink roof tiles. Santa Cruz has a classical layout—a series of straight radiating boulevards and concentric ring roads focused on the ancient city center. The Piray River supplies the city’s water, so the center was established near its bank. The river’s wide, sandy floodplain controls the shape of the modern city, restricting its growth westward. A long thin remnant of agricultural fields (center) has been isolated by the recent urban growth.
The Santa Cruz metropolitan area (2 million people) is one of the fastest-growing cities in the world. Recent growth has largely come from the expansion of agriculture—especially soybeans, sugar cane, and rice—and from petroleum and natural gas extraction. Manufacturing operations in the city produce soybean oil, dairy and meat products, wood products, leather, and alcohol. Oil and sugar refineries are also important. The city’s international airport (top right) is the country’s busiest.
Earlier courses of the Piray River appear in several parts of the image. These relict courses show that the river has flowed northwest (top left), northeast (green channels near the airport), and east (green channels, lower right). By switching its courses, the Piray has built the vast plain of fertile river sediment where the city and farmland now lie. Strong winds occasionally blow sand out of the river bed, making elongated dune fields (lower left and top left).