Analytical Solutions of Vertical Airflow in an Unconfined Aquifer with Rising or Falling Water Table

The rise and fall of the groundwater level can drive air flow in vadose zone. In turn, interact with water flow. When unconfined aquifer is covered by a low-permeability media, coupling more obvious. this study, conceptual model established for zone response to rapid fluctuations table. Water injection drainage experiments are conducted double-layered sand column thick layer (80.5 cm) coarse thin fine as cap. Different cap thickness (2 cm, 5 7.5 different (30 40 set experiments. Negative pressure (NP)/positive (PP) observed drainage/injection experiments, higher thicker layer. each experiment, NP or PP increases rapidly reach maximum early stage, gradually becomes zero late stage. Analytical solutions on three subdivided stages indicate permeability layer, well porosity media key controlling factors process also reveal formation mechanism This study has both theoretical significance engineering applications.