Views: 20 Author: pqwt Publish Time: 2022-11-10 Origin: PQWT
Comparing the ground water detector map with the in-situ retest or misalignment retest is an important measure to identify the true and false anomalies.
1, first of all, the original ground water detector map should be carefully analyzed, using the method described in "Technique No. 8" to see which points may be anomalies (including local block anomalies), and focus on these points when retesting, if the original ground water detector map even a If there is not even one anomaly on the original ground water detector map, and it is in a known water-poor area, do not retest, you should choose another line of measurement.
2, the original ground water detector map and retest map of the number of points to try to as many as possible, the benefit is to facilitate the puzzle; second is to retest if the difference between a point can be timely to find out the cause, to see if there may be which line missed a measurement point; third is that if there is no missed measurement, more than one point of the last point of the line and is a high value, the high value will be the color of the previous points pressed blue (the value has not changed, only the color has changed), the color of the two lines will be a large difference, in the analysis is easy to cause the illusion.
3, the depth of the ground water detector instrument used for the two measurements will remain the same as far as possible. If a 150 ground water detector instrument is used, another time with a 300 ground water detector instrument, with the 300 ground water detector instrument measured more than 150 meters below the part of the map if there is a high value layer, will also make the 150 meters above the part of the map of the color pressure more Blue, the color of the two lines of the map will be a large difference, in the analysis of easy to cause the illusion.
4, ground water detector original measurement map of anomalies such as high and low values of suspicion of downward transmission, misalignment retest distance to about 5 meters is good, if limited by the terrain should not be less than 3 meters. If there is a similar anomaly on the resurvey line, but it does not correspond to the position of the anomaly on the original line, we should add another misalignment resurvey line to see if the anomaly on the three lines is roughly a straight line. If the anomaly disappears on the second misalignment retest line, it is very likely that the anomalies on the other two lines are false anomalies.
5, if the anomaly on the original and retest map is a combination of high and low, but the high and low values on the two lines are opposite to each other, such a combination cannot be regarded as an anomaly, but just a coincidence.
6, the horizontal anomaly in the longitudinal direction can not be regarded as an anomaly if the difference in depth between the two lines is large.
7, a line of measurement of three joint reading requires three maps, measured twice is six maps, sent to the group too much too messy, but also not conducive to preservation, it is best to map the two measurements to a map, separated by an empty measurement point, so that the map is reduced by half, but also saves the process of the puzzle again, especially easy to analyze the two lines against each other, more advantages. If the maximum value of two diagrams on a map is measured to be very different, and thus the color of the diagram is also different (as shown above, the difference between the maximum value of the original and retest diagrams is large, indicating that the electromagnetic environment is not good), you can analyze the anomaly separately, without affecting the comparison. If the measurement points exceeded 15, the retest is a bit too crowded when measured on a map, so we have to separate the two maps and put them together again after the measurement.