---

Airborne electromagnetic imaging of canal-induced recharge on groundwater quality improvement in saline- affected alluvial region of NW India.

Rani P, Mishra A, Maurya VP, Chandra S, Choudhury J, Kumar KL, Rao NS, Singh KP, Sonkamble S, Nagaiah E, Raju KB, Akhil P, Verma SK.

NEAR SURFACE GEOPHYSICS

https://doi.org/10.1002/nsg.70016 

This study explores the impact of canal-induced recharge in the salinity-affected semi-arid region of northwest India using airborne electromagnetics (AEM) data, borewell lithology, and electrical log. AEM data reveal a 20-100 m thick moderate to high resistivity zone beneath the canals, indicating freshening of groundwater. It has been observed that the major canals were constructed earlier and aligned with the existing paleochannels, which enhanced vertical infiltration and deeper recharge compared to minor canals. Borewell data also confirms the progressive decline in groundwater salinity, with electrical conductivity (EC) converging to the EC value of canal water. The total volume of canal-induced recharge inferred from AEM resistivity is estimated to be ∼12,000 to ∼18,000 MCM, affecting about 20% of the study area.

Spatial distribution of the Canal-Induced Recharge zone and Resistivity cross section in Sri Ganganagar, Rajasthan.

Resistivity sections for profiles (a) A–A′ and (b) B–B′, passing through the major canals in the northern part of the study area.

---