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Accueil du site → Doctorat → États-Unis → 1995 → Integrated design and management of irrigation-drainage systems incorporating water quality aspects

Colorado State University (1995)

Integrated design and management of irrigation-drainage systems incorporating water quality aspects

Manguerra, Henry Barquez

Titre : Integrated design and management of irrigation-drainage systems incorporating water quality aspects

Auteur : Manguerra, Henry Barquez

Université de soutenance : Colorado State University

Grade : Doctor of Philosophy (PhD) 1995

Résumé
The design and management of irrigation-drainage systems in intensely irrigated areas of arid regions are traditionally based on an agricultural objective which is to preserve crop productivity despite the presence of saline high water tables. Current environmental constraints demand that the design and management strategies should now satisfy not only the agricultural objective but also a second objective, which is to protect the environment. The shift in objectives requires a departure from the traditional ways with which irrigation-drainage systems are designed and managed. A promising integrated irrigation-drainage system that satisfies both the objectives of crop productivity and environmental protection is formulated and evaluated. Its application is demonstrated using a representative cotton farm in the San Joaquin Valley, California over an 8-year period. The integrated system is composed of a series of no-drainage and drainage cycles. The no-drainage cycle is an extended period in which drainage is not allowed. The drainage cycle is a limited period in which drains are operated to restore the suitability of the system for growing crops. The integrated system is shown to preserve crop productivity while reducing the total drainage volume by 50-58 percent when compared to the traditional system. The corresponding reduction in salt removed by the drains is only 15-29 percent, reflecting the improvement in the efficiency of the drains in intercepting more salt per unit volume of water. A cost-benefit analysis has shown that the integrated system is economically more attractive than the traditional system. When design and management strategies are developed within a numerical modeling framework, the shift in the design and management objectives of irrigation-drainage systems would likewise require a change in the modeling philosophy. Models based on the standard linked and continuous modeling approaches are developed to illustrate this change. A new modeling approach based on a modified link formulation is introduced. It incorporates the three-dimensional modeling capability of the more rigorous continuous approach for the fully saturated zone but at the same time reasonably preserves the computational economy of the standard linked approach.

Mots clés : Applied sciences, Hydrology, Earth sciences, Civil engineering, Agricultural engineering

Accès au document : Proquest Dissertations & Theses

Page publiée le 28 février 2015, mise à jour le 6 novembre 2019