Soils and water

Soils and Water

Case studies showing how soil and water interact and how important soil is in the hydrological cycle.

Soil sits at the centre of the water cycle — storing rain, releasing it slowly to streams and plants, and filtering pollutants on the way to groundwater. The case studies here cover soil composition, a summary of the hydrological cycle, the classic jam-jar experiment, rivers and soil, dry lake beds in Turkey, pebble grading on beaches and the wetland landscape of the Somerset Levels.

Porosity, crusting and organic matter content control how much water soil absorbs and how much runs off the surface. Sandy soils drain quickly; heavy clays may waterlog; well-structured topsoil acts like a sponge that reduces flooding and drought stress for crops.

Understanding soil–water relationships is essential for managing floods, supplying drinking water and keeping agriculture productive in a changing climate. Explore the topics above to see these principles at work in familiar and surprising places.