Digging pits on the slopes just for the accumulation of run off is called

Contour trenching involves digging pits or trenches along the contour lines of a slope. These trenches accumulate runoff water, allowing it to infiltrate the soil rather than flowing down the slope and causing erosion. Bench terracing creates level platforms, contour terracing follows contours, and leveling creates flat surfaces - but specifically digging pits on slopes for runoff accumulation is contour trenching.