Is it true that Arch-gravity dams are lighter and less resource-intensive than conventional dams?

A gravity dam is somewhat thick, but an arch dam is relatively thin. Because the thickness of the top arch dam body is always only 3-5 m, the temperature can drop from the maximum to a very low value in a very short period before Magnesium oxide concrete expands.

Arch-gravity dams are thinner and use less material. It is a hybrid of an arch and a gravity dam. Water's inward compression lessens the lateral stress operating on the dam. The needed gravitational force is less.