Volga River Delta, Russia May 1991. The main channel of the Volga River (lower right corner) fans out into several channels as the river enters the northern edge of the large Volga River Delta. The lighter-colored, muddy-looking water of the Volga can be seen mixing with the extensive water of the very low-lying, more stagnant, swampy water of the delta. The paralleling, east-west aligned features (upper right and left middle) are alternating sand ridges (light lines) that are separated by numerous lakes (dark, linear-looking features). There are more than 700 salt lakes included within the salt marshes of the Volga River Delta. The important Russian city of Astrakan with a population that exceeds 500000 people is visible (upper center). Astrakan has developed into a vital urban area in spite of the fact that it is 72 feet (22 meters) below sea level. The city’s growth has been aided by several important factors including irrigated agriculture; natural gas production; source of medicinal materials and salts; an abundance of building products, such as sand and limestone; and water fowl and fish habitats. A variety of industrial activities, including a large producing gas field (pattern of intersecting, light-colored lines – bottom center) that is located along the east bank of the Volga River, has also helped Astrakan become an important city in this semiarid, steppe climate