Although two bands of clouds obscure part of this near-vertical photograph of metropolitan Houston, much urban infrastructure can be identified, such as Lake Houston (northeast of downtown), the source of most of the city’s drinking water. Numerous major highways converge on the downtown central business district, and two beltways (the inner loop—Interstate Highway 610, and the outer loop—partially constructed Beltway 8) encircle the city. Highly reflective areas of concrete and metals indicate concentrations of industrial and commercial activities. One such corridor extending eastward to Galveston Bay from near downtown is the Houston Ship Channel, home to many chemical plants and oil refineries. Just north of the causeway linking Galveston Island with the mainland is Texas City, a major site for oil refining and chemical processing. Houston has three main airports—large, V-shaped Houston Intercontinental Airport (visible north of downtown), Ellington Field (visible southeast of downtown), and Hobby Airport (obscured by cloud cover southeast of downtown). Residential street patterns are discernible in many of the surrounding communities. NASA Lyndon B. Johnson Space Center is east of Interstate Highway 45 immediately northeast of Clear Lake. East of Houston cultivated fields of rice flank the Trinity River. Lake Anahuac is the small brown, roughly circular body of water just south of Interstate Highway 10. This photograph provides a visual record of the sediment characteristics and turbidity of Galveston Bay.