Ground resistivity technique measurement for ice jam early warning at freeze-up period of the Yellow River

The terrain landform and the topographic feature in the Yellow River val ey vary considerably. Affected by the cold air flow from the areas of Siberia and Mongolia,the noteworthy icing arises to various extents in the main and branch streams in winter and spring. The fierce violence of the formed ice jam flooding and abruptness in increment of water level could easily result in crevasse and cause natural calamity. It is,therefore,very important to carry out studies on ice jam early warning system. The amount of ice flows under the ice cover and the growth of ice bodies in the freeze up period of the Yellow River are the key factors for the Yellow River ice jam early warning In the study,we measure the two phase resistivity of ice water with the ground resistivity measurement technology,plot the resistivity diagrams,digitalize the parameters of the ice jam formation, and the evaluate the growth of ice bodies and the accumulation of ice bulks,which provides valuable information for the ice jam protection and the natural disaster reduction. The results indicate that,at the stable stage of ice flow,the threshold is around 10Ω·m fol owing the decomposition of the resistivity cure by wavelet analysis During partial blockage of ice jam,the threshold increases up to about 100Ω·m. The apparent difference in the thresholds can be a criterion for judging the ice jam early warning. A practical method for ice jam early warning is,therefore,proposed the based on dif erences shown on the ground resistivity curves.