PLANET EARTH Freshwater

Only 3 percent of the water on our planet is fresh. Yet these precious waters are rich with surprise. All life on land is ultimately dependent upon fresh water. The mysterious tepuis（平顶山） of Venezuela（委内瑞拉） isolated mountain plateaus rising high above the jungle. This was the inspiration forArthur Conan Doyle's 'Lost World,' （亚瑟·柯南道尔的《失落的世界》）an imagined prehistoric land.



Here, strange towers of sandstone have been sculptured over the millennia by battering wind and torrential rain（倾盆大雨）. Moisture rising as water vapor from the surface of the sea is blown inland by wind. On reaching mountains, the moisture is forced upwards and as it cools, it condenses into cloud and finally rain - the source of all fresh water.



There is a tropical downpour（热带暴雨） here almost every day of the year. Fresh water's journey starts here, high in the mountains. Growing from humble streams to mighty rivers it will travel hundreds of miles to the sea. Angel Falls（委内瑞拉天使瀑布）, the highest waterfall in the world. Its waters drop unbroken for almost a thousand meters. Such is the height of these falls that long before the water reaches the base in the Devil's Canyon（恶魔峡谷） it's blown away as a fine mist.