Surface soil drying to explore flooding and waterlogging conditions over agricultural plains

CAPPELLETTI, LUCÍA M.; SÖRENSSON, ANNA A.; RUSCICA, ROMINA C.; SALVIA, M. MERCEDES

Kigali

Conferencia; WCRP Open Science Conference 2023. Advancing climate science for a sustainable future; 2023

wcrp

The dynamic of the surface soil drying offers an integrated perspective on soil responses to land cover and atmospheric conditions. This process can be quantified by the time it takes for the soil to dry without water input. Precipitation is by far the most common water input of the surface soil layer, but in some agricultural areas water input can also be related to irrigation, and less often to capillary effects. Our study focuses on a rainfed agricultural region with a shallow water table, where we aim to evaluate the time scale of surface soil dry-down events as a tool for understanding regional floods and waterlogging. Specifically, we are examining a flat area in the Argentinean Pampas, known for its susceptibility to floods and waterlogging, and is one of the most agriculturally-productive areas in South America. This work is based on the hypothesis that longer dry-down events may indicate flooding episodes, as the soil surface is expected to dry more slowly under flooded or waterlogged conditions.The dry-down events are taken from surface soil moisture data estimated by in situ sensors and L-band satellite missions. The occurrence of flooding and waterlogging is obtained using optical satellite information and reports from national and private agro-industrial institutions, together with in situ water table data. In this work, we attempt to integrate multiple tools and sources -lines of evidence- to analyze the mechanisms involved in flooding and waterlogging events.