Transient electromagnetic method and high-density resistivity method were used, Geological survey and prediction of paleo river courses within 100 meters below the surface. The point distance is 5 meters, the emission current is 30A, and the sampling interval is 0.8μs.

High-density resistivity method inversion diagram

Transient electromagnetic method inversion diagram

There is a low-resistance anomaly between 20m-30m at the left end of the measurement line (indicated by the red dotted line in the figure). The surface was exposed as gravel and pebbles, and the high-resistance anomalies near the surface were present, and the transient electromagnetic inversion results were basically consistent with the high-density data.