Erosion of soil

In many parts of the world, land application of organic waste is not only an economic imperative but also a management necessity in order to stem the degradation and erosion of soil. 

Natural Pollution of the Oceans, Frequently overlooked is what may be termed natural 1 pollution, which, when coupled with artificial (anthropogenic) pollution, contributes to the sum total of all pollutants found in fresh and ocean waters worldwide. Deep fissures in the ocean floor, fumaroles, and seamounts (underwater volcanoes) release megatons of sulfur-laden and other noxious gases into ocean water other discontinuities in the ocean basins release vast quantities of crude oil and other hydrocarbons. Surface volcanoes are major contributors to atmospheric pollution, much of which ultimately affects Earth s hydrosphere. The present dissolved solids content of the oceans represents natural water pollution that has taken place ever since the land masses rose above sea level—through a constant erosion of soil. 

Globally, volcanoes release about 17 150 metric tons (t) of arsenic per year into the atmosphere (It equals 1000 kg (Matschullat, 2000), 300). Other significant natural sources of gaseous arsenic emissions include geothermal vents, wind erosion of soils and sediments, forest and coal seam fires, and sea spray ((Cullen and Reimer, 1989), 740 (Nriagu, 1989) Chapter 3). Under reducing conditions in soils, fungi and... 

Zhu et al. (2004) reported the concentrations of 10 PAHs in four bodies of water in Hangzhou, China (July and November 1999 2002). The maximum levels of PAHs in the water bodies (34.4-67.7 pgl-1) were found in July, while significantly lower PAH concentrations (4.7-15.3 pgl-1) were measured in November. The measured PAH concentrations in sediments and soils, runoff water, and air particles were 224-4222 ngg-1, 8.3 pgl-1 and 2.3 pgm-3, respectively. Clearly, such substantial contamination may lead to acute toxic effects on aquatic organisms. However, the erosion of soil material does not contribute significantly to the contamination of sediments. The atmospheric PAH deposition to water bodies in the city area of Hangzhou was estimated to be 530tons/a, while the contribution of surface runoff water was... 

Particulate material (e.g., sand, silt, clay) which has been transported and deposited in the bottom of a body of water. Sediment input to a body of water comes from natural sources, such as erosion of soils and weathering of rock, or as the result of anthropogenic activities, such as forest or agricultural practices, or construction activities. The term can also describe a material that has been experimentally prepared (formulated) using selected particulate material (e.g., sand of particular grain size, bentonite clay, etc.). Volume 1(2), Volume 2(5,9). 

Glotfelty, D E., Leech, M.M., Jersey, J., Taylor, A.W. (1989) Volatilization and wind erosion of soil surface applied atrazine, simazine, alachlor, and toxaphene. J. Agric. Food Chem. 37, 546-551. 

Tetryl may be released to the air, water, and soil when old stores of the explosive ate destroyed by exploding or burning. However, tetryl has not been measured in air during any of these activities. Tetryl that was manufactured or stored at military installations, like Army ammunition plants, may still be present in the soil and water at or around these sites. Tetryl is not likely to evaporate into air from water or soil surfaces. However, tetryl may be present in air associated with dust from these sites. Tetryl appears to break-down rapidly in some soils. Picric acid, is one of the break down products of tetryl in soil. Tetryl probably does not easily travel from soil to groundwater. Erosion of soil from contaminated sites may release tetryl to nearby surface water. Once it is in the water, tetryl may dissolve or associate with small particles of suspended solids, sediments, or organic debris. Some of these particles will settle to the bottom. Tetryl breaks down rapidly in sunlit rivers and lakes but much more slowly in groundwater. It is not known whether tetryl will build up in fish, plants, or land animals. See Chapters 4 and 5 for more information on tetryl in the environment. 

The study shows the utility of clay studies to karst hydrology. These data show that suspended sediment discharged from a karst aquifer can be derived from erosion of soil tens of kilometers away from the recharge zone of the aquifer. The data also show that other clearly allochthonous material, such as wood and (probably man-made) fibers travel through the aquifer and are discharged at the springs. 

The different size modes reflect differences in particle sources, transformations, and sinks (Finlayson-Pitts and Pitts 2000). For example, coarse particles are generated by mechanical processes such as wind erosion of soil, wave action in the oceans, and abrasion of plant material. In contrast, many of the fine particles in the atmosphere are produced from either primary emissions from combustion sources or via atmospheric gas-to-particle conversions (i.e., new particle formation). The relative and absolute sizes of particle modes, as well as the number of modes, can vary greatly in different locations and at different times. In addition, the chemical composition of particles within one size... 

Before the advent of herbicides, weeds were removed by mechanical cultivation. Herbicides were adopted because they made weeding cheaper without any mechanical damage to the crop. Both methods involve more erosion of soil than is desirable. There are some other ways to cut down on the crop losses to weeds.205... 

The increasing inorganic-matter content within the upper few centimeters of peat corresponds to a period of rapidly rising population and urbanization of the watershed. Land-development activities associated with urbanization promote erosion by increasing the rainfall/runoff ratio (Lull and Reinhart, 1972) and by increasing stream velocity in channels adapted to lesser flows (Hewlett and Nutter, 1%9). Erosion of soil from the watershed and its transport to the salt marsh was directly observed in the field. 

Gillette, D. A. (1978). A wind tunnel simulation of the erosion of soil effect of soil texture, sandblasting, wind speed and soil condition on dust production. Atmos. Environ. 12, 1735-1743. 

Alternatively, carbamate pesticides can enter the atmosphere in different ways (viz., through application drift during spraying operations, wind erosion of soil, or volatilization), and it appears that pesticide concentration in the atmosphere is an important problem for human health and forest ecosystems. 

The formation of a water-insoluble association complex of poly(ethylene oxide) and poly(acrylic acid) is also the basis for a soil stabilization process to prevent erosion of soil on hillsides and river banks. 

In stiff, overconsolidated clays, cyclic lateral loads may open a gap (slot) between the pile and soil. The slot may gradually grow wider and deeper because of erosion of soil caused by the squeezing of water out of the gap. This erosion, in addition to the seafloor surface erosion and scour, may significantly affect the pile design computations. 

Soil Erosion. The erosion of soils involves the removal of soil particles and transportation of these particles under the influence of an air or water stream. Erosion under the influence of an air stream is more correctly termed deflation, but it is more often called wind erosion. The erosion of soils is a phenomenon responsible for great damage in agriculture, not only changing the structure and composition of the soil, but often removing all of the productive topsoil by the action of water or wind. 

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