Freshwater

Freshwater is water with low salinity. Compared to seawater, the salt content of freshwater is significantly lower. It consists of rivers, lakes, groundwater (wells), ice, and rain. In Somali usage, the term xareed (freshwater) typically refers to rainwater that is collected and stored in reservoirs, cisterns, or ponds.

Freshwater comprises a small fraction of all water on Earth; most of it is ocean water. The portion of freshwater available for use is even smaller, since much of it is frozen or locked in deep underground aquifers.

The water cycle

Freshwater originates from the water cycle. The sun causes water to evaporate from oceans and land; this vapor rises and becomes clouds, from which rain, snow, or hail falls. Because this evaporation process removes salt, rainwater is freshwater. Some rain flows into rivers, while some seeps into the ground and recharges underground water reserves.

Storage types

Freshwater storage is divided into: surface water (rivers, lakes, wetlands, springs), groundwater (aquifers, which are rock layers that hold water), and ice in polar regions. In arid countries such as Somalia, groundwater and rainwater collection are particularly important, because perennial rivers are scarce.

Human use

Agriculture uses the largest share of extracted freshwater, especially livestock watering. Industry and domestic use follow. Drinking water must be treated to remove bacteria and other contaminants; untreated water can spread diseases such as cholera and typhoid.

Water stress

Population growth, expansion of irrigated agriculture, industrial development, and climate change affect freshwater availability. In some regions, extraction from aquifers exceeds the rate of natural recharge. Along coasts, when groundwater is depleted, seawater intrudes and increases salinity.