In geophysical measurements, it is important to know the difference between monitoring, monitoring, and control program. Let’s discuss them one by one.
Measurement programs is about the decision of (1) which measurements should be carried out, (2) where the measurements should be made, (3) what measurement technique should be used, and (4) what form of presentation should be used. Example: chemical sampling, physical measurements, and air-borne measurements.
Monitoring programs is about repeated measurements and studies with time dependent changes. The time scale can be general, long time, temporary, or very temporary. The scale can be international, national, regional, local, and detailed. Example: Monitoring in (1) long term changes in temperature, (2) change in precipitation, (3) physical changes of the earth stress and structure, and (4) groundwater levels at tunnel constructions.
Control programs has clear aims with measurement instruction, analysis tools, presentation tools, structural storage of data, comparison with limits and restrictions, and control of measurement results. Measurement program is a part of control program.
Control programs is about (1) What is the aim of controlling? and why? (2) In which area? (3) What are the acceptable limits?
Example: control program in (1) regional water quantity (e.g. drinking water supplies), (2) regional quality (e.g. seawater intrusion), and (3) regional groundwater levels.
Type of sampling
In doing the geophysical measurements, there are different ways in taking the samples. Here are some of it:
Each of it has its own strengths and weaknesses.
- Directed: we can clarify the problem and identify the source (in case we highly know the place where we have to conduct the sampling
- Random: suitable to verify the treatment
- Systematic random, quadratic, and triangular: suitable to verify the treatment, define problem, identify source, evaluate the costs for treatment and deposition
- Stratified: suitable to evaluate the costs for treatment and deposition and identify source
Type of profiles
There are two types of profile: radial and linear.