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Accueil du site → Doctorat → Royaume-Uni → 1996 → Computer simulation of salinity control by means of an evaporative sink

University of Newcastle upon Tyne (1996)

Computer simulation of salinity control by means of an evaporative sink

Asghar, Muhammad Nadeem

Titre : Computer simulation of salinity control by means of an evaporative sink.

Auteur : Asghar, Muhammad Nadeem.

Université de soutenance : University of Newcastle upon Tyne

Grade : Doctor of Philosophy (Ph.D.) : 1996

Many intensively irrigated areas (especially in semi-arid environments) suffer from waterlogging and soil salinity because of the presence of saline groundwater conditions at shallow depth. Conventional wisdom holds that the best solution is to maintain a net flux of salt away from the rootzone by deliberate overirrigation (i.e. leaching) combined with watertable control by means of artificial drainage. In large contiguous irrigated basins this give rise to the problem of how to dispose of the saline drainage effluent. Where land is abundant and availability of water limits development (as in the Indus basin of Pakistan) it may be possible to devise an alternative strategy based on the concept of ’dry drainage’, which aims to achieve the necessary salt balance in irrigated fields by passive transfer to adjacent non-cropped areas. This thesis aims to investigate the range of conditions under which a sustainable dry drainage system might be created.A simulation model has been developed which accounts for the major processes governing behaviour of the shallow watertable and the distribution of salts. The three components of the dry draining system are : source (cropped area), sink (evaporative sink area) and saturated subsurface aquifer (transfer zone which also acts as a salt sink). Three computer models have been combined to create a comprehensive dry drainage model. An existing one-dimensional model of the soil-crop environment (WAVE) is adopted to represent the source. This is coupled to an existing two-dimensional model of groundwater flow (SUTRA). The third component, which represents the evaporative sink, has been developed specifically for this work (SINK). The resulting quasi-three dimensional model is capable of describing the entire land phase of the hydrological cycle in the dry drainage system.

Mots clés  : Irrigation ; Saline groundwaters ; Waterlogging Agricultural engineering Hydrology Soil science Agricultural engineering Hydrology Soil science

Annonce : EThOS (UK)

Proquest Dissertations & Theses

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