ABSTRACT
Lakes are traditionally under-valued resources to human society. Good water quality in lakes is essential for maintaining recreation and fisheries and for the provision of municipal drinking water. These uses are clearly in conflict with the degradation of water induced by agricultural use and by industrial and municipal waste disposal practices. The management of lake water quality is usually directed to the resolution of these conflicts. This chapter presents a summary of the 11 major types of lake origin. It explores the two other systems of classification which are based upon processes within lakes, and which are used universally, provide the basis upon which assessment strategies and interpretation are based. These are the physical or thermal lake classification and the classification by trophic level. The basic information required to characterise the ambient condition of a lake is based upon surveys of the various components of the lake system.
