GEOL105 Lecture Notes - Lecture 6: Flash Flood, Stream Gauge, Hydrograph
Document Summary
Throughout history, the deadliest and most common natural disaster. Example: floods in china in 1931 killed an estimated 2. 5 and 3. 7 million. This is the natural disaster you are most likely to encounter. If you come to a flooded road when you are driving or walking, simply remember, turn around don"t drown. May occur from: overflowing lakes, water in usually dry channels, excess runoff in roadways, and of course in overflowing streams. When discharge (q) is too much to be contained in the channel. Elevation of the stream surface above the bed (stage) exceeds the banks: this is the flood stage. In the u. s performed by u. s geological survey"s stream gage stations. Flood hydrograph nearest the rainfall area is highest narrowest. At b, the flood hydrograph crest at a lower level but lasts longer. At c, the flood crests at an even lower level and lasts longer. Two types of streams floods- each comes on and behaves differently.
