Which of these types of weathering requires the presence of water?

The weathering of rock by water is in two forms. One is the physical impact of moving water from rain, outflow, or tides. The other is solution, in which water dissolves minerals in the rock surfaces.

Rain and surface water can dissolve gases from the air to form dilute acids that can then chemically react with minerals. This type of erosion can also be seen on stone statues and monuments. The extreme form, which includes dissolved sulfur and nitrogen compounds, is referred to as "acid rain".