USE these words to fill in the blankspure urban mining
silt chemicals human bed animal salts factory minerals soil downstream sewage |
Where do rivers begin?
Rivers begin in mountains or hills where rain water or melting snow collects and forms tiny streams called gullies. Gullies either grow larger when they collect more water from runoff to become a stream or they meet up with a stream adding to water already flowing in that stream. When one stream meets another they merge. The smaller stream is called a tributary. It takes many tributary streams to make a river. A river grows larger as it collects more and more water from run off, gullies, streams and tributaries. Fill in the blanks
At the source of a river, the water is relatively ……………. As the water flows …………………………………. it picks up ……………. and ………………………. (including mineral …………) from the ……………. and rock in the river …………… .
Many other ………………………. enter river water as it flows downstream including …………………. waste, ………………………. ……………………………, agricultural and ……………………. runoff as well as …………………………… or ……………………………….. effluent. |