Feature Rivers Most of the world’s population live near rivers. They depend on rivers for drinking, washing, fishing and watering crops.   In remote forests or deserts, rivers may be the easiest way to travel. Dams may be built to prevent floods, to water nearby fields or produce electricity. If rivers are not controlled, drought or floods can cause disasters. Every year, millions of people suffer from shortage of water or flooding of homes and fields.     Even in Europe, flooding of major rivers threatens lives and causes tremendous damage to cities and farmland. In 2002, the worst European floods for many years caused more than 7 billion euro of damage. Meteosat weather satellites give early warning of heavy rainstorms so that flood defences can be prepared. ESA’s Envisat and ERS-2 spacecraft help rescue services by imaging flooded areas, day or night.     Satellites also show the best places to dig wells, how much water is in the soil and whether the rivers are rising or falling. This is very valuable in poor countries where such information is hard to obtain. Since 2002, ESA’s TIGER programme has been helping many African countries to monitor their rivers and wetlands and make the most of their available water.       Last update: 15 November 2010 Water world  •  Ice caps (http://www.esa.int/esaKIDSen/SEMEVKXJD1E_Earth_0.html)  •  Lakes (http://www.esa.int/esaKIDSen/SEM7PKXJD1E_Earth_0.html)  •  Oceans (http://www.esa.int/esaKIDSen/SEM9OKXJD1E_Earth_0.html)