ABSTRACT
Rapidly progressing problems with contamination of natural resources and associated public health concerns emphasize the growing demand for advanced capabilities to quantify fate and transport of contaminants in the vadose zone. Automated measurement technologies with high spatial resolution are required for continuous monitoring of subsurface chemical transport below potential point and nonpoint contaminant sources such as industrial and municipal waste disposal sites, accidental chemical spills, or agrochemicals applied over extended areas. Basic understanding of complex interactions between physical, chemical, and biological processes and the ability to early detect and assess the extension of migrating contaminant plumes is crucial for initiation of advanced remediation measures. Despite significant new developments of advanced measurement technologies and progress in characterizing solute transport processes over the last few decades, prediction of field-scale phenomena remains a challenge due to the inherent heterogeneity of the vadose zone.
