Ph.D. Dissertation – Koukoula Marika

Date of Event: 05/13/2021

Start Time: 2:00 pm


Civil & Environmental Engineering 

Koukoula Marika
PhD dissertation

Department of Civil & Environmental Engineering
University of Connecticut

2:00 PM – Thursday, May 13th, 2021


Meeting ID: 952 3139 5227, Passcode: 7j5MAQ


Advisory Committee:

Emmanouil N. Anagnostou (Major Advisor)
Efthymios I. Nikolopoulos (Associate Advisor)
Craig S. Schwartz (Associate Advisor)
Marina Astitha (Associate Advisor)
Malaquias Peña (Associate Advisor)

Land Surface-Atmosphere Interaction: The impact of soil moisture on precipitation and runoff generation


Precipitation-driven hydrometeorological hazards such as floods, droughts, and landslides have significant socioeconomic impacts. Understanding the complex interaction of precipitation with land surface processes and climate characteristics is, therefore, imperative for improving predictability of these extreme events. Soil moisture is an important hydrological state variable playing a crucial role in land-atmosphere interactions as it affects both precipitation and runoff generation.  In this work we investigate the impact of soil moisture uncertainty on simulated precipitation from Numerical Weather Prediction models under different climate and meteorological conditions. We then assess the combined effects of soil moisture on precipitation and the antecedent wetness conditions of the basin on the rainfall-to-runoff transformation process driving the catchment flood response under different basin scales and meteorological conditions. The study elucidate the complexity of the relationship between soil moisture and precipitation, suggesting that the control of soil water content on partitioning land surface heat fluxes has significant impacts on both the magnitude and spatial distribution of simulated precipitation. Results indicate different characteristics of the soil moisture-precipitation relationship during the cold and warm periods and under different climate and meteorological conditions. It is also shown that soil moisture affects runoff directly, changing the saturation level of the soil, and indirectly, through the impact on the magnitude and spatial distribution of precipitation. The combination of these two mechanisms results into high sensitivity of runoff generation, in terms of peak flow and runoff volume, on soil moisture condition. It is shown that this sensitivity of runoff to soil moisture varies under different antecedent wetness, basin scales and soil characteristics.

Published: April 29, 2021