Drilling wells to find underground water sources is an important field that human beings have continuously explored and developed in their long-term production and life. In this process, ground water detector, as an advanced detection technology, plays a crucial role. ground water detector, by utilizing various physical principles and technical means, can accurately detect the location of the ground water source, depth and water volume and other key information, which provides a scientific basis and guidance for drilling wells to find water. Commonly used ground water detector includes DC method, geomagnetic bathymetry, natural electric field frequency selection method and NMR method.
1、DC method ground water detector
DC method of physical exploration ground water detector is the earlier and widely used method. It makes use of the difference in the conductivity of the rock layer, through the artificial to the underground to provide stable electric current, observation of the earth current field change rule, so as to determine the geological structure of the underground. However, direct current method exists detection depth is not enough, the signal is vulnerable to shielding and the use of the shortcomings of the efficiency is not high.
2、Earth electromagnetic bathymetry ground water detector
Earth electromagnetic bathymetry ground water detector is the use of high-frequency electromagnetic field penetration shallow, low-frequency electromagnetic field penetration deep, in the field of the source and receiving point spacing under the conditions of the same, change the frequency of the electromagnetic field to achieve the purpose of detection. The method has the advantages of easy to use, deep detection and high resolution, but the signal is not stable, susceptible to interference by external factors.
3, natural electric field frequency selection method ground water detector
Natural electric field frequency selection method ground water detector is the use of the earth electromagnetic field as a source of work, based on the resistivity difference of underground rock layer, measurement of the earth electromagnetic field generated by a few different frequencies of the electric field component change rule, the study of underground electric section of the electrical changes to achieve the purpose of detection. The natural electric field frequency selector developed on this principle is invented by Chinese people themselves, which has the advantages of high working efficiency, simple use, cheap price, many manufacturers and obvious reflection of bedrock fracture zones, and good effect in groundwater survey, however, the principle of natural electric field frequency selector is still unclear, basically with reference to the evolution of foreign geomagnetic method of the branch of the audio geomagnetic method, but the data acquisition and analysis methods are completely different. But the data acquisition and analysis methods are completely different, there are shortcomings of the use of the effect is doubtful.
4、NMR nuclear magnetic resonance method ground water detector
NMR nuclear magnetic resonance method ground water detector as a new geophysical method to find water directly, using the difference of relaxation characteristics of hydrogen nuclei in water, observation and research of nuclear magnetic resonance signal change law, and then detect the existence of groundwater and its endowment characteristics. However, NMR water finding instruments are expensive and require experienced operators to operate.
In practical application, any single physical exploration method has certain limitations. Therefore, a combination of methods is needed for detection to improve accuracy and reliability. At the same time, the use of physical exploration method also needs to be combined with other information such as geology and hydrology for comprehensive analysis and interpretation.
Overall, the physical exploration method plays an important role in finding groundwater sources. With the continuous development of science and technology, it is believed that the future physical exploration technology will be more advanced and accurate. Although there are still some challenges and limitations in the current physical exploration method, through continuous research and practice, we are confident that we can overcome these difficulties and provide human beings with safer and more reliable groundwater resources.
