Kivikkoisuus

Kivikkoisuus is the degree to which a landscape is covered by stones and rock fragments, indicating how rocky the ground is. It refers to the visible surface stone content as well as the presence of bedrock close to the surface. The concept is used in geology, land-use planning, agriculture, and forestry to describe physical constraints related to soil depth, drainage, and rooting.

The term derives from the Finnish word kivi (stone) with the suffix -koisuus, which expresses a quality or degree. In practice, kivikkoisuus can be described qualitatively (low, medium, high) or quantitatively as a percentage of ground surface covered by stones larger than a chosen size.

Assessment methods include field surveys that estimate stone cover, soil maps that indicate coarse fragment content, and remote sensing or LiDAR analyses that help map stone distribution over larger areas. Measurements may focus on surface rock cover, depth to effective soil, and the density of rock fragments within a soil horizon.

Kivikkoisuus influences land use in several ways. High stone content reduces arable potential, complicates tillage, increases drainage challenges, and raises construction costs for buildings and infrastructure. It can also affect hydrology, erosion risk, and frost action. In forestry, rocky soils can limit planting density but may provide heritage value for certain ecosystems and influence microhabitats.

In Finland and other glaciated regions, kivikkoisuus is common in moraine and esker landscapes and tends to decrease with soil deepening or bedrock exposure. It is a factor in regional planning, agricultural policy, and environmental conservation, guiding strategies for cultivation, drainage solutions, and infrastructure design.