Here the land is low, flat or very gently sloping, and the temperatures are warmest. The soils are often deep and fertile and so the land is best suited to intensive agriculture with arable farms and market gardens. Close to the river the land may be marshy or at risk from flooding and is therefore kept as permanent pasture for livestock.

The largest settlements and greatest concentration of road and rail links are found in the lower course. The largest industrial areas, which need good communications, many workers and large areas of flat land are also located here. This part of a river valley has the greatest population density.