Groundwater flow-paths through shallow-perch and deep-regional basaltic aquifers at the Golan Heights, Israel, are reconstructed by using groundwater chemical and isotopic compositions. Groundwater chemical composition, which changes gradually along flow-paths due to mineral dissolution and water-rock interaction, is used to distinguish between shallow-perched and deep-regional aquifers. Groundwater replenishment areas of several springs are identified based on the regional depletion in rainwater δ18O values as a function of elevation (-0.25‰ per 100 m). Tritium concentrations assist in distinguishing between pre-bomb and post-bomb recharged rainwater. It was found that waters emerging through the larger springs are lower in δ18O than surrounding meteoric water and poor in tritium; thus, they are inferred to originate in high-elevation regions up to 20 km away from their discharge points and at least several decades ago. These results verify the numerically simulated groundwater flow field proposed in a previous study, which considered the geological configuration, water mass balance and hydraulic head spatial distribution.
Bibliographical noteFunding Information:
This study was funded by a Grant from the Israeli Water Commission. The authors thank Mr. Haim Hemo from the Geological Survey of Israel (GSI) for his help in the fieldwork, Dr. Ittai Gavriely and Dr. Bettina Shilman from the GSI for their help and discussions, the GSI laboratory staff for efficient and precise work, and for Prof. Harvey Blatt for his comments on the manuscript.
- Altitude effect
- Golan heights