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Water: From a chemical point of view, water (H2O) is a compound consisting of two hydrogen atoms (H) and one oxygen atom (O). As per DIN 4049-1, the term “water” is a collective name for all naturally occurring kinds of water, thus including substances that have dissolved, emulsified and suspended in it including microorganisms [DIN4049-1] (Image: Global distribution of water) |
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According to DIN 4049-1, the hydrologic cycle is the permanent changing of water in its state and location, with its main components being:
[DIN4049-1] (Video: Global hydrologic cycle) |
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The water circulates from one reservoir to the next, whereas the seas (oceans and their semi-enclosed and adjacent seas) that cover about 70 % of the Earth’s surface represent the largest water reservoir. Depending on the water reservoirs involved, we distinguish between three different hydrologic cycles:
(Video: The three different hydrologic cycles) |
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The hydrologic balance equation (in general also called water inventory or water budget equation) is a quantitative description of the natural hydrologic cycle, i.e. the interrelation between the components and environmental compartments of water (hydrosphere), soil (pe-dosphere) or air (Earth’s atmosphere). The components are:
(Image: Basic hydrologic balance equation) |
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The regional hydrologic cycle is in a small way also influenced by the “urban hydrologic cycle” that is shaped by man. The mere development of urbanisation (the spread of the urban lifestyle) has a massive influence on the water balance and results in both quantitative and qualitative changes of the units to be balanced in the catchment area under observation. According to Klinger, the hydrologic balance equation for urban areas is described as:
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(Image: Attention!) The proper functionality and leak-tightness of the drain and sewer system has a massive impact on the hydrologic cycle in urban areas, and thus also on both the quantity and quality of groundwater as a resource. Combined with the effects of the global climate change (global warming, climatic shifts), this fact becomes a national challenge. What is important in this context is to realise that due to the very distinct local and environmental … |
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Congratulations! You have successfully finished the first part of the lesson. The lesson continues in the form of a script. Please take all further information from the following script “Hydrologic cycle”. Stay curious! |
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Aug 06, 2015 This module provides an essential basic understanding of the global hydrologic cycle along with the quantitative description of the natural and urban hydrological cycle through the hydrologic balance equation. After completing this module, you will have knowledge regarding:
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Aug 04, 2005
The term obstacle in trenchless installation must be viewed from a contractual [Liepe02] as well as a technical point of view. From a technical aspect, one differentiates between:
Non-removable obstacles in trenchless installation … |
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Jun 02, 2004 The terms and definitions listed in the following represent an abridged excerpt from the comprehensive glossary of the technical book: Stein, D.: "Trenchless Technology for Trenchless Installation of Cables and Pipelines" [Stein05a]. Abrasiveness: Air-(gas)-flushing: |
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Feb 16, 2011 Rehabilitation and Maintenance of Drains and Sewers Structure and Limiting Conditions of Sewer Systems - Historical Outline (Image: Age distribution of the sewers in German Federal Republic (position 1990) [Kedin87]) With the industrial development at the start of the 19th Century there arose, especially in the large cities of Europe (e.g. in Great Britain in 1840 and in Germany in 1842) the necessity for the building of sewers, i.e. of installations for the collection and drainage of sewage [DIN4045:1985]. Since then they have been constantly extended and today present … |
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Feb 16, 2011 Sewer systems are constantly or intermittently subject to differing physical, chemical, bio-chemical and biological stresses. Depending on
these stresses can lead sooner or later to the depletion of the originally available wear reserve of 100 % (Bild 2.1) (Abschnitt 4.1) [ATVM143-1:1989] [ATVM143-2b]. |
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Nov 03, 2004 Leakiness can also occur as a result of other damage such as:
The causes of this type of damage will be dealt with in more detail in the appropriate sections. |
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Feb 11, 2011 News Karlsruher Institut für Technologie Researchers Study the Geothermal Potential of Aquifers in Large Cities
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The crust of the earth consists mostly of rock materials that are made up of naturally formed quantities of different minerals (mineral aggregates) or of only one mineral type. This can occur as soil or as rock and sometimes of both in sequence. Soil occurs through the weathering of rock. It exists either in original strata (weathered soils) or has been transported by wind, water or ice and deposited (sediments) (Abschnitt 4.5.1) [Soos96]. Rock is … |
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With non-cohesive soils, the individual particles or parts of the rock material form an agglomeration that possesses a measure of strength due to the friction of the particle surfaces. Their properties are influenced by the particles size, particle size distribution, particle form and particle roughness. Depending on the base material, they are often resistant to weather conditions. According to DIN 1054 [DIN1054:2005], the non-cohesive soils comprise … |
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With cohesive soils, the particles adhere to each other due to electrostatic surface forces and thus form an interconnected formable mass. Their properties (strength behaviour) are influenced largely by the water content, the particle size and the clay mineral content (Abschnitt 4.3.1.5). They are sensitive to weathering. According to DIN 1054 [DIN1054:2005], this type of soil comprises clays, clayey silts, and silts (e.g. sandy clay, sandy silt, … |
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According to DIN 1054 [DIN1054:2005], this type of soil comprises peat or sapropel and inorganic soils with organic admixtures of animal or plant origin (Tabelle 4.3.1.1.3), when the weight percentage is more than 3% or 5% (e.g. sand containing humus, sapropel, or sand containing peat, organic silt or clay, loam). Depending on the degree of decay, such soils possess a fibrous, fleecy or earthy texture and a high degree of water retention or water … |
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Also, according to ISO14688-1 [DINENISO14688:2004], volcanic soils are understood to be, "pyroplastic materials produced and formed by explosive volcanic eruption; e.g. pumice, scoria, volcanic ash." The particles of volcanic soils are generally blistered and the compactness or density of the strata (Abschnitt 4.3.1.4) is relatively low. The soils possess a characteristic colour that depends on the original magma or rock. The main components of … |
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With fine soils, the shape of the particle is solely dependent on the type of the mineral. Quartz, lime and dolomite are generally cubic, clay minerals generally flat and halloysite is longitudinal (elongated). With coarse soils, the particle shape and the roughness is dependent on the type of rock material as well as the transport and weathering history. Increasing transport distances leads to rounding of the edges and the smoothing of the particle. … |
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(Image: Flow chart for the identification and description of soils based on ISO 14688-1 [DINENISO14688a]) The primary differentiating feature of mineral soils is the size of the individual particles. This determination is the first step in the identification and classification of a soil type (Bild 4.3.1.3). A review of the identification of the type of soil with reference to particle size is shown in Tabelle 4.3.1.3. (Table: Identification and particle … |
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