Water balance and the behaviour of different paving surfaces

The concept of water balance is frequently used to describe the main hydrological processes occurring in natural catchments. It can also be applied to urban catchments and in this paper the water balance principle is applied to small‐scale samples of various paving materials. In particular, the relative importance of runoff, evaporation and infiltration is studied. This paper discusses these processes and describes some experimental measurements of water balance on various paving materials and the moisture content distribution within the materials.