After the Rain Falls: River Systems
Recall that this module deals with water as an agent of change across the surface of the Earth. Up until now, we have focused on how water gets into the atmosphere through evaporative processes and is transported with latent heat energy. While a larger portion of that water vapor will condense and fall out as precipitation over the oceans, a smaller percentage falls as precipitation over continents. For that water to make its way back to the oceans, it must be transported either above or below ground. The rest of the module addresses surface water transport in the form of rivers.
River systems comprise only a small portion of the freshwater on Earth, and cover only a tiny percentage of the global land surface extent. For humans, however, rivers are incredibly important and have been for thousands of years. They serve as sources of the drinking water we need to stay alive, conduits for transportation, sources for irrigation of agricultural lands, recreation centers, religious sites, sources of fish as a food resource, and the cleansing agent that carried off the grime and waste that humans produce in abundance. Rivers also provide habitat for wildlife that humans appreciate and enjoy in a myriad of ways, shady refuges for weary travelers in otherwise sun-baked lands, and through annual floods, the rich soils that make agriculture possible in much of the world.
One such river is the Danube, a major waterway in Europe. Log in to BBLearn and under Module 4, complete "Assignment 4.7: Blue Danube."
River systems comprise only a small portion of the freshwater on Earth, and cover only a tiny percentage of the global land surface extent. For humans, however, rivers are incredibly important and have been for thousands of years. They serve as sources of the drinking water we need to stay alive, conduits for transportation, sources for irrigation of agricultural lands, recreation centers, religious sites, sources of fish as a food resource, and the cleansing agent that carried off the grime and waste that humans produce in abundance. Rivers also provide habitat for wildlife that humans appreciate and enjoy in a myriad of ways, shady refuges for weary travelers in otherwise sun-baked lands, and through annual floods, the rich soils that make agriculture possible in much of the world.
One such river is the Danube, a major waterway in Europe. Log in to BBLearn and under Module 4, complete "Assignment 4.7: Blue Danube."