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Author Robati, A.; Barani, G.A.
Title Modeling of water surface profile in subterranean channel by differential quadrature method (DQM) Type Journal Article
Year 2009 Publication Applied Mathematical Modelling Abbreviated Journal
Volume (down) 33 Issue 3 Pages 1295-1305
Keywords Subterranean channel, Qanat, Differential quadrature method, Water surface profile, Porous media
Abstract This study, investigates the hydraulic of flow in a subterranean channel headspring. The continuity and momentum equations of flow in porous media considering real conditions were used and the basic equation of flow in a subterranean channel was resulted. This equation is very similar to the spatially varied flow with increasing discharge. An equation, defining the hydraulic parameters of a subterranean channel section was adopted. Then differential quadrature method (DQM), was applied to the equation of flow in subterranean channel, consequently the water surface profile was resulted. To illustrate the rightness of model, the hydraulic parameters of flow in the Gavgard branch of the Joopar Goharriz Qanat were measured and the water surface profile was determined. This water surface profile was compared to the water surface profile computed by the model, which are in good agreement.
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ISSN 0307-904x ISBN Medium
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Notes Approved no
Call Number THL @ christoph.kuells @ Robati20091295 Serial 249
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Author Klock, H.; Külls, C.; Udluft, P.
Title Estimation of relative recharge values for the northern Kalahari catchment, Namibia Type Journal Article
Year 2000 Publication Journal of African Earth Sciences Abbreviated Journal
Volume (down) 30 Issue 4 Pages 47-48
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Call Number THL @ christoph.kuells @ Klock2000estimation Serial 33
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Author Schwiede, M.; Duijnisveld, W.H.M.; Böttcher, J.
Title Investigation of processes leading to nitrate enrichment in soils in the Kalahari Region, Botswana Type Journal Article
Year 2005 Publication Physics and Chemistry of the Earth, Parts A/B/C Abbreviated Journal
Volume (down) 30 Issue 11 Pages 712-716
Keywords Nitrate, Arenosol soils, Semi-arid, Kalahari, Cattle, Chloride, Travel time
Abstract In Southern Africa elevated nitrate concentrations are observed in mostly uninhabited semi-arid areas. In the Kalahari of Botswana groundwater locally exhibits concentrations up to 600mg/l. It is assumed, that nitrate found in the groundwater originates mainly from nitrogen input and transformations in the soils. Our investigations in the Kalahari between Serowe and Orapa show that cattle raising is an important source for enhanced nitrate concentrations in the soils (Arenosols). But also in termite mounds very high nitrate stocks were found, and under natural vegetation (acacia trees and shrubs) nitrate concentrations were mostly unexpectedly high. This nitrate enrichment in the soils poses a serious threat to the groundwater quality. However, calculated soil water age distributions in the unsaturated zone clearly show that today’s nitrate pollution of the groundwater below the investigation area could originate from natural sources, but cannot be caused by the current land use for cattle raising.
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ISSN 1474-7065 ISBN Medium
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Notes Integrated Water Resources Management (IWRM) and the Millennium Development Goals: Managing Water for Peace and Prosperity Approved no
Call Number THL @ christoph.kuells @ Schwiede2005712 Serial 276
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Author Lightfoot, D.R.
Title Moroccan khettara: Traditional irrigation and progressive desiccation Type Journal Article
Year 1996 Publication Geoforum Abbreviated Journal
Volume (down) 27 Issue 2 Pages 261-273
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Abstract A 300 km network of khettara (qanat) subsurface irrigation channels was excavated in the Tafilalt basin beginning in the late 14th century. More than 75 of these chains provided perennial water following the breakup of the ancient city of Sijilmassa. Khettara continued to function for much of the northern oasis until the early 1970s, when new technologies and government policies forced changes. Data on origins, maintenance, and current use were collected from archival sources, aerial photographs, Landsat imagery, and from interviews. Insufficient water resources and unsustainable practices have dramatically lowered the water table, drying up khettara. This has resulted in a loss of local control over water resources, abandonment of a sustainable irrigation system, and progressive desiccation.
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ISSN 0016-7185 ISBN Medium
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Notes Approved no
Call Number THL @ christoph.kuells @ Lightfoot1996261 Serial 257
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Author Wolfe, P.
Title The Simplex Method For Quadratic Programming Type Journal Article
Year 1959 Publication Econometrica Abbreviated Journal
Volume (down) 27 Issue Pages 170
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Call Number THL @ christoph.kuells @ Wolfe1959 Serial 285
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