UC Davis

My PhD research celebrates nearly two centuries of theoretical advancements in soil-water interactions, specifically focusing on soil infiltration. Over time, mathematical models and experimental techniques have enriched our understanding of infiltration processes, contributing to improved water management, soil conservation, and environmental practices. Despite the proliferation of models enhancing our understanding of soil-water interactions, the diversity of available options poses challenges in model selection and data analysis. To address these challenges, I first conducted a detailed literature review tracing the theoretical and historical evolution of infiltration models. This review categorized 138 models based on their conceptual and empirical foundations, covering a wide spectrum of applications to guide researchers in selecting appropriate models and challenge existing theories to advance infiltration modeling. Building on this review, I addressed the uncertainty in extracting soil hydraulic properties, such as saturated hydraulic conductivity (Ks) and sorptivity (S) from experimental infiltration data to evaluate the physical meaning of these estimated properties across various infiltration models. As such, I performed a metadata analysis using a global database of 5,023 cumulative infiltration curves to assess the variability in (Ks) and (S) parameters across various one- and three-dimensional models and extraction techniques. My analysis revealed insights into the robustness of current practices applied in soil water parameter estimation. Another key finding from my literature review on infiltration modeling is the significant gap in theoretical frameworks studying the impact of soil structure on infiltration. To this end, I conducted a meta-analysis systematic review to establish correlations between infiltration rates and soil structural properties, emphasizing the need for integrated approaches. As we advance, leveraging large databases and advanced analytics can enhance our understanding of soil-water interactions and address real-world challenges. My research calls for continued scientific rigor and curiosity to uncover new relationships of dominant processes in soil science.