ABSTRACT
This chapter presents many topics that are fundamental to the analysis of hydrologic data. It discusses a variety of characteristics of environmental data, of which hydrologic data are but one example. Topics covered in this chapter include dimensions of physical phenomena, data precision, discrete versus continuous data, data type and quality, and lastly data transformation and graphing. In hydrologic analyses we encounter equations that are, as well as some that are not, dimensionally homogeneous. An equation is dimensionally homogeneous when the dimensions are the same on each side of the equal sign. For practical purposes, continuous data are often made discrete through either the measurement process, or to simplify an analysis. The reason for distinguishing between continuous and discrete data is that different mathematics are used for each type. Data type can refer to various characteristics of environmental data. Environmental data have both magnitude and dimension. This chapter has presented some basic issues concerning environmental data.
