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Soil Sealing
Soil sealing or soil surface sealing is the loss of soil resources due to the covering of land for housing, roads or other construction work. Covering or replacing the topsoil with '' impervious'' materials like asphalt and cement as a result of urban development and infrastructure construction paired with compaction of the underlying soil layers results in the mostly irreversible loss of relevant soil ecosystem services. The global rise in population has heightened the need for soil sealing, which in turn leads to the degradation of land. Sealed land is a serious form of land take (use of land specifically for building settlements, roads, and businesses). Soil sealing and land take together leads to the complete loss of soil functions, including its biological, physical and chemical properties. Impacts Replacing natural soil with man-made surfaces greatly affects the process of water infiltration. These artificial surfaces don't allow water to seep through as easily as soi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural & Impervious Cover Diagrams EPA
Nature is an inherent character or constitution, particularly of the ecosphere or the universe as a whole. In this general sense nature refers to the laws, elements and phenomena of the physical world, including life. Although humans are part of nature, human activity or humans as a whole are often described as at times at odds, or outright separate and even superior to nature. During the advent of modern scientific method in the last several centuries, nature became the passive reality, organized and moved by divine laws. With the Industrial Revolution, nature increasingly became seen as the part of reality deprived from intentional intervention: it was hence considered as sacred by some traditions (Rousseau, American transcendentalism) or a mere decorum for divine providence or human history (Hegel, Marx). However, a vitalist vision of nature, closer to the pre-Socratic one, got reborn at the same time, especially after Charles Darwin. Within the various uses of the word t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat-island Effect
Urban areas usually experience the urban heat island (UHI) effect; that is, they are significantly warmer than surrounding rural areas. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak, under block conditions, noticeably during the summer and winter. The main cause of the UHI effect is from the modification of land surfaces, while waste heat generated by energy usage is a secondary contributor. Urban areas occupy about 0.5% of the Earth's land surface but host more than half of the world's population. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas. Monthly rainfall is greater downwind of cities, partially due to the UHI. Increases in heat within urban centers increases the length of growing seasons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Erosion
Soil erosion is the denudation or wearing away of the Topsoil, upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, Atmosphere of Earth, air (wind), plants, and animals (including humans). In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, Aeolian erosion, wind (aeolian) erosion, Zoogenic erosion, zoogenic erosion and anthropogenic erosion such as tillage erosion. Soil erosion may be a slow process that continues relatively unnoticed, or it may occur at an alarming rate causing a serious loss of topsoil. The loss of soil from Agricultural land, farmland may be reflected in reduced crop production potential, lower surface water quality and damaged drainage networks. Soil erosion could also cause sinkholes. Human activities have increased by 10–50 times the rate at which erosion is occurring world-wide. Exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impervious Surface
Impervious surfaces are mainly artificial structures—such as pavements (roads, sidewalks, driveways and parking lots, as well as industrial areas such as airports, ports and logistics and distribution centres, all of which use considerable paved areas) that are covered by water-resistant materials such as asphalt, concrete, brick, stone—and rooftops. Soils compacted by urban development are also highly impervious. Environmental effects Impervious surfaces are an environmental concern because their construction initiates a chain of events that modifies urban air and water resources: * The pavement materials seal the soil surface, eliminating rainwater infiltration and natural groundwater recharge. This can cause urban flooding. An article in the '' Seattle Times'' states that "while urban areas cover only 3 percent of the U.S., it is estimated that their runoff is the primary source of pollution in 13 percent of rivers, 18 percent of lakes and 32 percent of estuari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Consumption
Land consumption as part of human resource consumption is the conversion of land with healthy soil and intact habitats into areas for industrial agriculture, traffic ( road building) and especially urban human settlements. More formally, the EEA has identified three land consuming activities: #The expansion of built-up area which can be directly measured; #the absolute extent of land that is subject to exploitation by agriculture, forestry or other economic activities; and #the over-intensive exploitation of land that is used for agriculture and forestry. In all of those respects, land consumption is equivalent to typical land use in industrialized regions and civilizations. Since often aforementioned conversion activities are virtually irreversible, the term land loss is also used. From 1990 to 2000, of open space were consumed in the U.S. In Germany, land is being consumed at a rate of more than every day (~ per 10 years). In European Union, land take is estimated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Compaction
In geotechnical engineering, soil compaction is the process in which stress applied to a soil causes densification as air is displaced from the pores between the soil grains. When stress is applied that causes densification due to water (or other liquid) being displaced from between the soil grains, then consolidation (soil), consolidation, not compaction, has occurred. Normally, compaction is the result of heavy machinery compressing the soil, but it can also occur due to the passage of, for example, animal feet. In soil science and agronomy, soil compaction is usually a combination of both engineering compaction and consolidation, so may occur due to a lack of water in the soil, the applied stress being internal suction due to water evaporation as well as due to passage of animal feet. Affected soils become less able to absorb rainfall, thus increasing Runoff (water), runoff and erosion. Plants have difficulty in compacted soil because the mineral grains are pressed together, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walloon Region
Wallonia ( ; ; or ), officially the Walloon Region ( ; ), is one of the three regions of Belgium—along with Flanders and Brussels. Covering the southern portion of the country, Wallonia is primarily French-speaking. It accounts for 55% of Belgium's territory, but only a third of its population. The Walloon Region and the French Community of Belgium, which is the political entity responsible for matters related mainly to culture and education, are independent concepts, because the French Community of Belgium encompasses both Wallonia and the bilingual Brussels-Capital Region but not the German-speaking Community of Belgium, which administers nine municipalities in Eastern Wallonia. During the Industrial Revolution, Wallonia was second only to the United Kingdom in industrialization, capitalizing on its extensive deposits of coal and iron. This brought the region wealth, and from the beginning of the 19th to the middle of the 20th century, Wallonia was the more prosperous h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brownfield Land
Brownfield is previously-developed land that has been abandoned or underused, and which may carry pollution, or a risk of pollution, from industrial use. The specific definition of brownfield land varies and is decided by policy makers and land developers within different countries. The main difference in definitions of whether a piece of land is considered a brownfield or not depends on the presence or absence of pollution. Overall, brownfield land is a site previously developed for industrial or commercial purposes and thus requires further development before reuse. Examples of post industrial brownfield sites include abandoned factories, dry cleaning establishments, and gas stations. Typical contaminants include hydrocarbon spillages, solvents and pesticides, asbestos, and heavy metals like lead. Many contaminated post-industrial brownfield sites sit unused because the cleaning costs may be more than the land is worth after redevelopment. Previously unknown underground w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Contamination
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons (such as naphthalene and benzo(a)pyrene), solvents, pesticides, lead, and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical substance. The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapour from the contaminants, or from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting clean ups are time-consuming and expensive tasks, and require expertise in geology, hydrology, chemistry, computer m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil-adjusted Vegetation Index
Empirically derived NDVI products have been shown to be unstable, varying with soil colour, soil moisture, and saturation effects from high density vegetation. In an attempt to improve NDVI, Huete developed a vegetation index that accounted for the differential red and near-infrared extinction through the vegetation canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an a .... The index is a transformation technique that minimizes soil brightness influences from spectral vegetation indices involving red and near-infrared (NIR) wavelengths. The index is given as: :\mbox=\frac where L is a canopy background adjustment factor. An L value of 0.5 in reflectance space was found to minimize soil brightness variations and eliminate the need for additional calibration for different soils. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normalized Difference Vegetation Index
The normalized difference vegetation index (NDVI) is a widely-used metric for quantifying the health and density of vegetation using sensor data. It is calculated from spectrometric data at two specific bands: red and near-infrared. The spectrometric data is usually sourced from remote sensors, such as satellites. The metric is popular in industry because of its accuracy. It has a high correlation with the true state of vegetation on the ground. The index is easy to interpret: NDVI will be a value between -1 and 1. An area with nothing growing in it will have an NDVI of zero. NDVI will increase in proportion to vegetation growth. An area with dense, healthy vegetation will have an NDVI of one. NDVI values less than 0 suggest a lack of dry land. An ocean will yield an NDVI of -1 Brief history The exploration of outer space started in earnest with the launch of Sputnik 1 by the Soviet Union on 4 October 1957. This was the first man-made satellite orbiting the Earth. Subseq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Respiration
Soil respiration refers to the production of carbon dioxide when soil organisms respire. This includes respiration of plant roots, the rhizosphere, microbes and fauna. Soil respiration is a key ecosystem process that releases carbon from the soil in the form of CO2. CO2 is acquired by plants from the atmosphere and converted into organic compounds in the process of photosynthesis. Plants use these organic compounds to build structural components or respire them to release energy. When plant respiration occurs below-ground in the roots, it adds to soil respiration. Over time, plant structural components are consumed by heterotrophs. This heterotrophic consumption releases CO2 and when this CO2 is released by below-ground organisms, it is considered soil respiration. The amount of soil respiration that occurs in an ecosystem is controlled by several factors. The temperature, moisture, soil nutrient, nutrient content and level of oxygen in the soil can produce extremely disparate r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
