WJEC Geography Practice Test

Rivers transport materials in different forms depending on whether the material is dissolved or in solid form. The one that remains dissolved in solution as it is transported is the dissolved load. This consists of minerals that have dissolved into the water as ions, so they move with the flow invisibly and can travel long distances without settling. By contrast, the suspended load is made of very fine solid particles held up in the water, the bedload includes larger particles that roll or slide along the river bed, and saltation describes particles bouncing along the bed. Only the dissolved load stays in solution; the others are physical solids that remain as separate particles or grains. For example, minerals from rock weathering can dissolve and be carried as ions in the water, rather than as visible particles.