Why are some river basins vulnerable to flooding?
The basin is in a place and/or shape that makes it unable to contain a large influx of water. This can be from steep channeling that constricts water flow, or flatter areas. For instance, the upper tributaries of the Mississippi routinely flood when a combination of spring rain and snowmelt enter the rivers. The Mississippi itself doesn’t have very high banks, so when a similar influx over a larger watershed pumps water into this major river, it can spill its banks and cover thousands of square miles of what is generally farmland. One other factor in flooding is often caused by us stupid people trying to channel a river where Nature doesn’t want it to go, by putting up dikes and levees. For instance, St. Louis is largely dry only due to the artificial channeling of the Mississippi. If those levees were ever to break, it would suck to live in St. Louis. Other prominent flooding areas of the world are the Yangtze (Yellow River) in China, which floods regularly and enormously due to natur
