– Všetko čo študent potrebuje
Elena, Helena
Štvrtok, 18. augusta 2022
Water resources
Dátum pridania: 22.11.2002 Oznámkuj: 12345
Autor referátu: aradvan
Jazyk: Angličtina Počet slov: 5 790
Referát vhodný pre: Stredná odborná škola Počet A4: 20.2
Priemerná známka: 2.98 Rýchle čítanie: 33m 40s
Pomalé čítanie: 50m 30s

While brushing teeth and shaving - do it with faucets off, followed by brief rinse.
 Recycling and conservation can make important contributions to increasing water supplies in the near future. Since agriculture uses a large percentage of our water, devices to reduce irrigation losses that are inexpensive and easy to install are needed. Individuals can assist by reducing water consumption.

The hydrologic cycle (fig.1)

The hydrologic cycle is the chain of the history of the water. The global water cycle is driven by solar energy, and a little bit by the rotation of the earth and tide forces. The cycle involves the total earth system comprising the atmosphere, the hydrosphere, lithosphere and biosphere. The hydrosphere includes all the water at and near the near the surface of the earth. All of the water in the hydrosphere is caught up in the hydrologic cycle. The largest single reservoir in the hydrologic cycle, by far, consists of the world’s oceans, which contain 97,5% of the water in the hydrosphere. Lakes and streams together contain only 0,016% of the water. The main processes of the hydrologic cycle involve evaporation into, and precipitation out of the atmosphere. Precipitation onto land can re-evaporate, infiltrate into the ground, or run off over the ground surface. Water that sinks in the ground may also flow back to the oceans. The oceans are the major sources of evaporation water because of their vast areas of exposed water surface. Most of the fresh water is locked up as ice, mainly in the large polar ice caps. Even the groundwater beneath continental surfaces is not all fresh. Groundwater exists wherever water penetrates through the surface. Groundwater has passed through the rock on aquifer and has been naturally filtered to remove some impurities. Usually, groundwater is found, at most, a few kilometers into the crust. Groundwater is by far the largest reservoir of unfrozen freshwater. This extractable body of groundwater occurs in openings between grains in alluvial and sedimentary rocks – pore water; in fractures usually abundant only near the ground surface – fissure water, and in tubular openings in soluble rocks; and openings in lava formed by flow and gas expansion during solidification – cavern water. The water table is not always below ground surface. Where the water table locally intersects the ground surface, the result may be a lake, a stream, or a spring. Groundwater can flow laterally through permeable soil and rock, from higher elevations to lower, from areas of abundant infiltration to drier ones, or from areas of little groundwater use toward areas of heavy use.
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