Investigations of hydrostructural processes in the soil medium

Amjad T Assi, Purdue University

Abstract

Food security and water security are among the main global challenges. These challenges are more profound in arid and hyper-arid countries which are seeking to maximize their local food production under harsh environment, limited water resources and limited fertile soil. Soil and water are among the imperative playing factors in this field. Neither food security nor water security can be achieved without adapting suitable agro-environmental practices. Moreover, an integrated management of these agro-environmental practices requires a quantitative understanding of the soil-water interaction. Such understanding would be impossible without having measurable parameters that characterize the soil hierarchical organization and its hydraulic functioning with water. The pedostructure concept provides the missing conceptual linkage between the soil organization and its hydraulic functionality through a set of physical parameters each of which quantifies a specific physical and structural property of soil medium. This research developed and evaluated a simple, reliable and reproducible methodology for characterizing the soil behavior. This characterization was done through a set of measurable state variables and hydro-structural parameters that describe not only the soil organization but also its hydraulic functionality. Such characterization has been considered a grand challenge in soil physics. A TypoSoil™ apparatus was used for providing continuous and simultaneous measurement of the three state variables of the two soil moisture characteristic curves: water retention characteristic curve and soil shrinkage characteristic curve. Moreover, a methodology was installed to accurately determine the hydro-structural parameters by optimization of the adjustment of the theoretical equation on the measured curves. Two native Aridisols in the State of Qatar named locally Rodah soil and Sabkha soil were used in this study. The results showed that the developed methodology in this research is simple, accurate and reliable and can be used for providing a solid basis in developing suitable techniques for soil reclamation, and other agro-environment practices such as irrigation with low quality water, and groundwater water recharge. It is a strong tool for managing the water security and food security. One significant application of the research result is in the field of quantifying, and managing the green water which plays an imperative role in food and water security.

Degree

Ph.D.

Advisors

Mohtar, Purdue University.

Subject Area

Soil sciences|Environmental engineering

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