# PQWT Underground Water Detector Maps Review

You are here:  These kinds of maps are easy to be misjudged as "curves are too smooth, no water"or "all points are the same, we can not determine if there is water". But if we have a further analyze of the three maps, we will get different result:

1, For the original profile map, we can see it has a high value layer centered on 180 meters, the upper and lower edges are 120 and 230 meters respectively, roughly symmetrical. We cant determine only by this map.

2, I have drawn a number of small red circles on the curves map,  there are two close curves in each red circle. Why this happened? Because for smooth profile maps, the upper and lower parts of the high-value layer will inevitably have a contour with the same value, which reflected in the curves map is that the curves lines will appear in pairs.This will be difficult to find if we dont compare from left to right.

3. If you compare the curves carefully , you can find there is only one curve between the third and fourth red circle, but not a pair.

4. If the upper and lower edges of the high value layer is gradual, high possibility of no water, but if it is abrupt, there will be high possibility of having water, the more abrupt it is, the higher possibility of water existing, which reflects on the curves maps is the curves become sparse or missing between 2 certain curves. In this curve map, the two curves between the third circle and fourth circles become one, this means it become sparse, which is consistent with the rules described above. What is missing in this map is is just one curve, indicating that only one edge is abrupt.

5. Is the abrupt change in the upper edge or lower edge? We can not tell it from the curve map.

6, We can read the processed profile map, the color of low value layer above the high value layer is grayish white, the color of low value layer under the high value layer is dark blue, which has a bigger difference, our experience is "big values is no problem, but small difference is not good", so big difference is better, we can know the mutation layer is at the lower edge.

7. As we can see from the processed map, the most obvious measurement points of the lower mutation edge are 1, 2, 6, and 7 points, that is to say, there are water at each point , but these four points are the best.

8, This case is granite, drill point final used is point 6. Final result: 90 meters, 2 cubic meters/h; 120 meters, 4 cubic meters/h; 220 meters. 15 cubic meters/h;more than 230 meters, large broken layer ,more than 30 cubic meters/h ; at where is 42 cubic meters/h , stop drilling.