Leakage detection for reservoir dam by electrical resistivity meter

  Leakage detection for reservoir dam by electrical resistivity meter

                

                                                     Figure 1 Leakage survey result by ERT 

                                     (a)Zohdy method inversion, bottom value is resistivity

                                (b)Back projection method inversion,bottom vaule is resistivity's common logarithm

                 Bottom vaule is resistivity's common logarithm

 Figure 2  Leakage survey result by ERT (Line 2)

Dam has leakage as uaual, but leakage was increased by earthquakes in local. In order to block leakage, leakage channel is required to ascertain, So we use multi-electrode resistivity system to do survey. 

Figure 1 is result line 1, Figure 1 (a) and (b) are the results of using Zohdy method and Back projection method we developed.

In the two graphs,although the absolute value of the resistivity is different,the relative distribution of the resistance value on profile is very close, both two display low-resistance areas in left and right. Also depth and horizontal position of the corresponding low -resistance band are relatively consistent, and they can indicate the water leakage channel of dam.

Figure 2 is result Line 2 (back projection inversion method developed by us),can also clearly see a relatively low -resistant area,which is also  reflection of the leakage channel. Depth is consistent with the depth of the two low -resistance areas in No. 1 section.