RIVERS Easier - A river is a natural stream of fresh water larger than a brook or creek. A river flows toward another river, an ocean, a lake, or other large body of water.

Harder - A river's source may be rainfall, a melting snowfield or a glacier, a spring, or the overflow of a lake. Streams that flow at a river source are the headwaters and are at the river's highest elevation. Most river headwaters begin in hills or mountain, but as the river flows downstream, it gains more water from other streams, rivers, springs, added rainfall, and other water sources.

Rivers have always been important for travel, transportation, and trade routes. Most settlements were built along major rivers. Rivers are also important for farming because river valleys and plains provide fertile soils. Farmers in dry regions irrigate their cropland using water carried by irrigation ditches from nearby rivers.

Rivers also are an important energy source Rivers also are an important energy source. During the early industrial era, mills, shops, and factories were built near fast-flowing rivers where water could be used to power machines. Today steep rivers are still used to power hydroelectric plants and their water turbines.

Rivers ♦ SUMMARY Rivers are the most obvious and significant feature of the landscape. They transport water by gravity, from headwaters to ocean.. For surface water, the cycle lasts an average of eleven days; that is, globally, the entire amount of surface water is replaced every eleven days.