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Interception (water)
Interception refers to precipitation that does not reach the soil, but is instead intercepted by the leaves, branches of plants and the forest floor. It occurs in the canopy (i.e. canopy interception), and in the forest floor or litter layer (i.e. forest floor interception ). Because of evaporation, interception of liquid water generally leads to loss of that precipitation for the drainage basin, except for cases such as fog interception, but increase flood protection dramatically, Alila et al., (2009). Intercepted snowfall does not result in any notable amount of evaporation, and most of the snow falls off the tree by wind or melts. However, intercepted snow can more easily drift with the wind, out of the watershed. Conifers have a greater interception capacity than hardwoods. Their needles gives them more surface area for droplets to adhere to, and they have foliage in spring and fall, therefore interception also depends on the type of vegetation in a wooded area. Mitscherlich ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rain Drops 2 Bg 20090606
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water for hydroelectric power plants, crop irrigation, and suitable conditions for many types of ecosystems. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts. If enough moisture and upward motion is present, precipitation falls from convective clouds (those with strong upward vertical motion) such as cumulonimbus (thunder clouds) which can organize into narrow rainbands. In mountainous areas, heavy precipitation is possible where upslope flow is maximized within windward sides of the terrain at elevation which forces moist air to condense and fall out as rainfall along the sides of mountains. On the leeward side of mountains, desert climates can exist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaf
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf but in some species, including the mature foliage of ''Eucalyptus'', palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves are flattened and have distinct upper (adaxial) and lower ( abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll that is essential for photosynthesis as it absorbs light ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Ball
A water ball or water walking ball is a large inflatable sphere that allows a person inside it to walk across the surface of a body of water. The giant ball is usually two metres in diameter and has a zippered entrance to allow for easy entry and exit. The water ball is similar to the zorb but it has only one layer and is designed for water travel rather than down-hill rolling. In the United Kingdom, the balls have been used at swimming pools, marinas and lakes in an effort to keep children fit. History One of the first water balls appeared in the film Diamonds Are Forever (film), Diamonds Are Forever (1971) and in the Beach Boys music video, ''Getcha Back'' (1985). Charles Blane Jones designed the first water ball for public distribution in 1998. Safety The Federal government of the United States, United States Government has warned of the dangers of using the balls, saying it "does not know of any safe way" to avoid the dangers of suffocation and drowning, among other ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest Floor Interception
Forest floor interceptionGerrits, A.M.J. and Savenije, H.H.G. 2011. (invited) Forest floor interception. In Levia, D.F., Carlyle-Moses, D.E. and Tanaka, T. (Eds.), Forest Hydrology and Biogeochemistry: Synthesis of Past Research and Future Directions. Ecological Studies Series, No. 216, Springer-Verlag, Heidelberg, Germany is the part of the (net) precipitation or throughfall that is temporarily stored in the top layer of the forest floor and successively evaporated within a few hours or days during and after the rainfall event. The forest floor can consist of bare soil, short vegetation (like grasses, mosses, creeping vegetation, etc.) or litter (i.e. leaves, twigs, or small branches). See also * Interception (water) * Canopy interception Canopy interception is the rainfall that is intercepted by the canopy of a tree and successively evaporates from the leaves. Precipitation that is not intercepted will fall as throughfall or stemflow on the forest floor. Many methods exist to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canopy Interception
Canopy interception is the rainfall that is intercepted by the canopy of a tree and successively evaporates from the leaves. Precipitation that is not intercepted will fall as throughfall or stemflow on the forest floor. Many methods exist to measure canopy interception. The most often used method is by measuring rainfall above the canopy and subtract throughfall and stem flow (e.g., Helvey and Patric 965. However, the problem with this method is that the canopy is not homogeneous, which causes difficulty in obtaining representative throughfall data. Another method that tried to avoid this problem is applied by e.g., Shuttleworth et al. 984 Calder et al. 986 and Calder 990 They covered the forest floor with plastic sheets and collected the throughfall. The disadvantage of this method is that it is not suitable for long periods, because in the end the trees will dry due to water shortage, and the method is also not applicable for snow events. The method by Hancock and Crowther 9 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Throughfall
In Hydrology, throughfall is the process which describes how wet leaves shed excess water onto the ground surface. These drops have greater erosive power because they are heavier than rain drops. Furthermore, where there is a high canopy, falling drops may reach terminal velocity, about , thus maximizing the drop's erosive potential. Rates of throughfall are higher in areas of forest where the leaves are broad-leaved. This is because the flat leaves allow water to collect. Drip-tips also facilitate throughfall. Rates of throughfall are lower in coniferous forests as conifers can only hold individual droplets of water on their needles. Throughfall is a crucial process when designing pesticides for foliar application since it will condition their washing and the fate of potential pollutants in the environment. See also *Stemflow *Canopy interception Canopy interception is the rainfall that is intercepted by the canopy of a tree and successively evaporates from the leaves. Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infiltration (hydrology)
Infiltration is the process by which water on the ground surface enters the soil. It is commonly used in both hydrology and soil sciences. The infiltration capacity is defined as the maximum rate of infiltration. It is most often measured in meters per day but can also be measured in other units of distance over time if necessary. The infiltration capacity decreases as the soil moisture content of soils surface layers increases. If the precipitation rate exceeds the infiltration rate, runoff will usually occur unless there is some physical barrier. Infiltrometers, permeameters and rainfall simulators are all devices that can be used to measure infiltration rates. Infiltration is caused by multiple factors including; gravity, capillary forces, adsorption and osmosis. Many soil characteristics can also play a role in determining the rate at which infiltration occurs. Factors that affect infiltration Precipitation Precipitation can impact infiltration in many ways. The am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stemflow
In hydrology, stemflow is the flow of intercepted water down the trunk or stem of a plant. Stemflow, along with throughfall, is responsible for the transferral of precipitation and nutrients from the canopy to the soil. In tropical rainforests, where this kind of flow can be substantial, erosion gullies can form at the base of the trunk. However, in more temperate climates stemflow levels are low and have little erosional power. Measurement There are a variety of ways stemflow volume is measured in the field. The most common direct measurement currently used is the bonding of bisected PVC or other plastic tubing around the circumference of the tree trunk, connected and funneled into a graduated cylinder for manual or a tipping bucket rain gauge for automatic collection. At times the tubing is wrapped multiple times around the trunk is order to ensure more complete collection. Determining factors Precipitation The primary meteorological characteristics of a rainfall event tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stormwater Management With Trees
Stormwater, also spelled storm water, is water that originates from precipitation (storm), including heavy rain and meltwater from hail and snow. Stormwater can soak into the soil ( infiltrate) and become groundwater, be stored on depressed land surface in ponds and puddles, evaporate back into the atmosphere, or contribute to surface runoff. Most runoff is conveyed directly as surface water to nearby streams, rivers or other large water bodies (wetlands, lakes and oceans) without treatment. In natural landscapes, such as forests, soil absorbs much of the stormwater. Plants also reduce stormwater by improving infiltration, intercepting precipitation as it falls, and by taking up water through their roots. In developed environments, such as cities, unmanaged stormwater can create two major issues: one related to the volume and timing of runoff (flooding) and the other related to potential contaminants the water is carrying (water pollution). In addition to the pollutants carried ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Throughfall
In Hydrology, throughfall is the process which describes how wet leaves shed excess water onto the ground surface. These drops have greater erosive power because they are heavier than rain drops. Furthermore, where there is a high canopy, falling drops may reach terminal velocity, about , thus maximizing the drop's erosive potential. Rates of throughfall are higher in areas of forest where the leaves are broad-leaved. This is because the flat leaves allow water to collect. Drip-tips also facilitate throughfall. Rates of throughfall are lower in coniferous forests as conifers can only hold individual droplets of water on their needles. Throughfall is a crucial process when designing pesticides for foliar application since it will condition their washing and the fate of potential pollutants in the environment. See also *Stemflow *Canopy interception Canopy interception is the rainfall that is intercepted by the canopy of a tree and successively evaporates from the leaves. Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autumn
Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September ( Northern Hemisphere) or March ( Southern Hemisphere). Autumn is the season when the duration of daylight becomes noticeably shorter and the temperature cools considerably. Day length decreases and night length increases as the season progresses until the Winter Solstice in December (Northern Hemisphere) and June (Southern Hemisphere). One of its main features in temperate climates is the striking change in colour for the leaves of deciduous trees as they prepare to shed. Date definitions Some cultures regard the autumnal equinox as "mid-autumn", while others with a longer temperature lag treat the equinox as the start of autumn. In the English-speaking world of high latitude countries, autumn traditionally began with Lammas Day and ended around Hallowe'en, the approxima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring (season)
Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of the term varies according to local climate, cultures and customs. When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere and vice versa. At the spring (or vernal) equinox, days and nights are approximately twelve hours long, with daytime length increasing and nighttime length decreasing as the season progresses until the Summer Solstice in June (Northern Hemisphere) and December (Southern Hemisphere). Spring and "springtime" refer to the season, and also to ideas of rebirth, rejuvenation, renewal, resurrection and regrowth. Subtropical and tropical areas have climates better described in terms of other seasons, e.g. dry or wet, monsoonal or cyclonic. Cultures may have local names for seasons which have little equivalence to the terms originating in Europe. Meteoro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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