ABSTRACT
The terms ‘measurement’ and ‘monitoring’ and are often used interchangeably, but they have specific and different meanings. Measurement of an environmental parameter involves assigning a numerical quantity to its magnitude by carrying out some kind of gauging. Estimation, on the other hand, is the approximate judgement or opinion of this magnitude. Monitoring involves collecting and interpreting a number of measurements or estimates over a period of time. It usually involves an element of comparison, either with itself or with some external benchmark, such as an environmental quality standard or a guideline value.
