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[7]: 1151 There could also be abrupt water cycle responses to changes in the land surface: Amazon deforestation and drying, greening of the Sahara and the Sahel, amplification of drought by dust are all processes which could contribute. The scientific understanding of the likelihood of such abrupt changes to the water cycle is not yet clear.
The water cycle is essential to life on Earth and plays a large role in the global climate system and ocean circulation. The warming of our planet is expected to be accompanied by changes in the water cycle for various reasons. [24] For example, a warmer atmosphere can contain more water vapor which has effects on evaporation and rainfall.
Alternate wetting and drying (AWD) is a water management technique, practiced to cultivate irrigated lowland rice with much less water than the usual system of maintaining continuous standing water in the crop field. It is a method of controlled and intermittent irrigation.
Within the tropics, distinct, wet and dry seasons emerge due to the movement of the Intertropical Convergence Zone or Monsoon trough. [38] The dry season greatly increases drought occurrence, [39] and is characterized by its low humidity, with watering holes and rivers drying up. Because of the lack of these watering holes, many grazing animals ...
Expansive soils are the most problematic in regions with very defined wet and dry periods, as opposed to areas that maintain a certain level of moisture throughout the year, as this annual cycle causes the soils to expand and swell every year. [3] Water can also be introduced into the soil through people, or their infrastructure.
Pluvial lakes represent changes in the hydrological cycle: wet cycles generate large lakes, and dry cycles cause the lakes to recede. Accumulated sediments show the variation in water level. During glacial periods, when the lake level is fairly high, mud sediments will settle out and be deposited.
Surge Irrigation is a variant of furrow irrigation where the water supply is pulsed on and off in planned time periods (e.g. on for 1 hour off for 1½ hour). The wetting and drying cycles reduce infiltration rates resulting in faster advance rates and higher uniformity [4] than continuous flow.
A common method to reduce future swelling in expansive soils is to subject the soil to wetting and drying cycles prior to construction of the lining. [6] Lab testing has shown that subjecting a clayey soil to wetting and drying cycles leads to a hysteresis of shrinkage in the soil, significantly reducing its free swelling potential. [7]