SOIL, WATER, AND ENVIRONMENTAL PHYSICS ACROSS SCALES

Preferential flow (PF) is a fundamentally important hydrologic process that influences a variety of earth surficial processes. However, PF quantification and prediction remain notoriously elusive.This project seeks to utilize extensive real-time soil moisture monitroing data that have been collected over many years to extract critical information about PF occurence in various soils and landscapes. The controls of PF occurrencewill be grouped into site factors (including landform unit and soil type) and temporal factors (including initial soil moisture, precipitation characteristics, and plant growth stage). A framework for classifying these key controlswill then be developed asa means of estimating the frequency of PF occurrence in diverse soil-landscapes. This effort will address a grand challenge in soil hydrology, i.e., to develop basic hydrologic principles and tools to further understand flow and transport processes through an irregular and interconnected real-world soils and landscapes. Since hydrology often triggers 'hot spots' and 'hot moments' of biogeochemical reactions and ecological functions, improved detection and quantification of PF also have considerable implications for enhanced determination of chemical fluxes and ecosystem functions.