Hydrology

Abstract

Students of water quality benefit from a knowledge of hydrology. The basic composition of water differs among components of the hydrosphere, e.g., rain water is less concentrated in minerals than runoff, and runoff usually does not contain as much dissolved mineral matter as groundwater. One needs to know about the movement of water through the hydrologie cycle to appreciate why such differences occur. In most discussions, water quality cannot be separated entirely from water quantity. For example, the amount of nutrient entering a water body in an industrial effluent depends on the volume or flow rate of the effluent in addition to its nutrient concentration. This chapter provides a brief discussion of the hydrologie cycle and some simple methods of water measurement.