SOIL SALINIZATION DUE TO SALTWATER INTRUSION IN COASTAL REGIONS: THE ROLE OF SOIL CHARACTERISTICS AND HETEROGENEITY

Abstract

Soil plays a vital role in maintaining ecosystem functionality, supporting biodiversity, facilitating successful crop production, and ensuring socio-economic stability. Soil quality is, however, constantly threatened by various factors, such as adverse climate conditions, hydrogeological processes, and human activities. One particularly significant stressor is soil salinity, which has a detrimental effect on soil quality. This study focuses specifically on understanding how soil properties contribute to the accumulation of surface soil salinity in the presence of shallow saline groundwater. To achieve this objective, advanced groundwater modeling techniques are employed to simulate saltwater intrusion in a riparian area known as Altes Land in northern Germany. A realistic representation of the salinization process is created and evaluated using a comprehensive dataset of hydrogeological information specific to the region. Additionally, the study examines the influence of soil heterogeneity on regional soil salinity by varying soil properties through devising six distinct scenarios for generating the numerical models that represent variations in soil texture and structure. The study reveals that regional soil texture and layering arrangement significantly influence the availability of water and the propagation of saline water in the vadose zone, and are major contributors to surface soil salinity. Subtle alterations and simplifications, often inconspicuous or deemed inconsequential in the context of small-scale experiments, may carry substantial ramifications for the formulation of enhanced management strategies in regions characterized by low elevation and influenced by groundwater salinity. Furthermore, the insights gained from this research provide valuable information for applications in agricultural practices and environmental conservation.