The relationship between floodwater infiltration and groundwater recharge of a shallow alluvial aquifer in a hyper-arid desert was studied in the Arava valley, Israel. The study implemented an experimental system that simultaneously monitors all three hydrological domains controlling the recharge process: (1) floodwater stages on land surface, (2) water-content variations in the deep vadose zone, and (3) groundwater response to the infiltration. This experimental system makes use of a new technique for installing flexible time-domain reflectometry probes for continuous monitoring of the vadose zone moisture profiles. Water infiltration was monitored in controlled infiltration experiments and during a natural flood. The monitoring setup allowed real-time tracking of the wetting-front propagation velocities and assessment of water fluxes through the vadose zone. The results revealed a complex infiltration process that includes matrix and preferential flow together with lateral flow.
Bibliographical noteFunding Information:
We thank Michael Kugel for his technical assistance and creative ideas in establishing the experimental setups, Mr. Ami Shaham from the Arava Drainage Authority for providing valuable assistance and data on the study area and Mr. Ilan Polak for providing creative drilling solutions. This research was supported by the Israel Science Foundation (Grant #276/03), the 6th framework program of the European Commission (WADE, GOCE-CT-2003-506680), Israel water authority, and by funds provided to the International Arid Lands Consortium (IALC) by the USDA Forest Service and by the USDA Cooperative State Research, Education, and Extension Service. The authors are grateful to Prof G. de Marsily and the anonymous reviewer who significantly improved the manuscript through their constructive comments.
- Arid land
- Vadose zone