Water Movement through a Shallow Vadose Zone: A Field Irrigation Experiment

Abstract

Surface irrigation water percolating below the crop rooting zone is important for groundwater recharge in agricultural areas overlying shallow aquifers. The objective of this study was to characterize water movement through the shallow vadose zone following surface irrigation. Two infiltration plots were installed in each of three predominant local soil types. Plots were instrumented to measure soil water content and shallow groundwater level. Data were used to calculate water infiltration, velocity of propagation of the wetting front, water fluxes, and water level response following irrigation. Results showed a low to moderate infiltration rate (0.001–0.056 m h−1), relatively low levels of propagation of the wetting front (0.13–0.79 m h−1), water flux (0.001–0.13 m h−1), and shallow groundwater response (0.01–0.1 m) in Fruitland sandy loam and Werlog clay loam soils. In the Abiquiu‐Peralta soil, however, a higher infiltration rate (0.002–0.124 m h−1), wetting front propagation (0.28–3.75 m h−1), water flux (0.007–0.925 m h−1), and water level response (0.01–0.14 m) were observed. Results from this study helped to improve our understanding of the surface water and shallow groundwater interactions in an irrigated valley in northern New Mexico. The field data set obtained in this study can benefit future model characterization and contribute to extrapolating local results to larger spatial areas.