ABSTRACT
The infiltration capacity of a soil, and hence the relationship between overland flow and throughflow, depends on the texture of the soil, on its thickness and its degree of compaction. Certainly in human terms the most far-reaching and devastating consequence of excessive uncontrolled runoff is soil erosion, and there are many areas in which constant vigilance against its effects are essential. The nature of the soil, the severity of the slopes, the geological structure, the rainfall characteristics, and the type of farm enterprise all play their part in affecting the nature and extent of soil erosion in any one area. The interstitial water is a nuisance, its presence makes the soil heavy, and the object of any drainage scheme is to get rid of it, to lower the water-table, thereby raising the soil temperature through reducing evaporation, and at the same time aerating the soil.
