Soil -water interaction: Lessons across scales
Abstract
Understanding and modeling water flow behavior at the field scale is integral to various environmental and agricultural applications. Unfortunately, this understanding is challenged with preferential flows rendering the use of Darcian fluxes, developed at the laboratory scale, unable to describe the flow at the field. Preferential paths development in the field is the result of the complex interaction of multiple processes relating to the soil's structure, moisture level, shrinkage induces stresses, and biological activities. Visualizing and characterizing the cracking behavior and preferential paths evolution of soils across the soil depth has always been one of the key challenges and a major barrier against scaling up existing hydrologic concepts and models to account for preferential flows. In this study, the evolution of soil's internal stress due to shrinkage as well as the effect of shrinkage on TDR estimates of water contents are explored at the laboratory scale. Then, the evolution of the preferential paths volume at different soil depths and moisture conditions is assessed by a new methodology to visualize preferential paths at the field scale. Results from different soil types (the savage soil vs. the Chalmers soil) and different landuses (corn/tilled field vs. soy bean no-till fields in the Chalmers soil) are presented. Finally, the effect of introducing scaling concepts to the hydrology curriculum is explored by quantifying its effect on students' enhanced knowledge and decision making skills.
Degree
Ph.D.
Advisors
Mohtar, Purdue University.
Subject Area
Hydrologic sciences|Environmental science|Environmental engineering
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