Some Aspects of Gully Development, Classification and Control

The various types of gully cross-sections are described and shown to be dependent upon the relative importance or down-scour, side-scour and bank degradation, and it is shown that the type of the mean cross-section is determined by the dominant one of these three processes. Not only is the relative importance of the developmental process indicated by the mean cross-section, but also the stage of developnent of the gully. A means by which the stage of development may be ascertained is important because it is the first step in selecting the best method of treatment. A discussion of the forces underlying the developmental processes is given, and the conditions for complete stability are indicated. The effects of grade reduction, stream sorting, and sediment load upon the development of gullies are deduced. The artificial treatments by man are discussed in the light of these deductions. A method for reclaiming major gullies, which are in the early stages of development, is given.