Search results
Results from the WOW.Com Content Network
Another commonly encountered term is the Special Flood Hazard Area, which is any area subject to inundation by a 100-year flood. [25] A problem is that any alteration of the watershed upstream of the point in question can potentially affect the ability of the watershed to handle water, and thus potentially affects the levels of the periodic floods.
Urban flooding is the inundation of land or property in cities or other built environment, caused by rainfall or coastal storm surges overwhelming the capacity of drainage systems, such as storm sewers. Urban flooding can occur regardless of whether or not affected communities are located within designated floodplains or near any body of water. [1]
The Doña Ana County Flood Commission in the U.S. state of New Mexico defines an arroyo as "a watercourse that conducts an intermittent or ephemeral flow, providing primary drainage for an area of land of 40 acres (160,000 m 2) or larger; or a watercourse which would be expected to flow in excess of one hundred cubic feet per second as the result of a 100 year storm event."
The map to the right shows a flood map for the City of York, including the floodplain for a 1 in 100-year flood (dark blue), the predicted floodplain for a 1 in 1000 year flood (light blue) and low-lying areas in need of flood defence (purple). The most sustainable way of reducing risk is to prevent further development in flood-prone areas and ...
Spate irrigation (from the English word spate, meaning: a. a flood or inundation. b. a river flooding its banks) uses seasonal floods of rivers, streams, ponds and lakes to fill water storage basins. It is an ancient method of irrigation in arid and semi-arid climates in the Middle East, North Africa, West Asia, East Africa and parts of Latin ...
The flood pulse concept explains how the periodic inundation and drought (flood pulse) control the lateral exchange of water, nutrients and organisms between the main river channel (or lake) and the connected floodplain. [1] The annual flood pulse is the most important aspect and the most biologically productive feature of a river's ecosystem.
Drinking water treatment plants are also at risk. Most U.S. cities and towns get drinking water from rivers and lakes, and water treatment plants tend to be near the water bodies from which they draw.
Fluvial terraces can be used to measure the rate at which either a stream or river is downcutting its valley. Using various dating methods, an age can be determined for the deposition of the terrace. Using the resulting date and the elevation above its current level, an approximate average rate of downcutting can be determined.