Research On Geometric Specular Resistivity Image Generation And Abnormal Recognition

There are lots of researches in the use of transient electromagnetic method for geological exploration and generating the apparent resistivity contour map of geologic body at this stage. Because of the colors in apparent resistivity contour map corresponds to the distribution status of geologic body, the deduction of the distribution status of abnormal geologic body can be based on the recognition for the areas showing abnormal apparent resistivity in the contour map. This recognition method is used to find stable geological factors unfavorable to facilities in construction project. There are lots of mountains in Yunnan, easy to cause geological disasters such as landslide and debris flow, and bring difficulties to the choice of transformer substation construction site. In order to ensure the safe and stable operation of the transformer substation, it is necessary to collect the apparent resistivity data of geologic body of construction site, and draw it into contour map, then recognize and analyse the anomaly geological areas such as subterranean cavitation, groundwater may be reflected on contour map. But at this stage, this kind of recognition method is mainly in artificial stage, with the increase of the size and complex distribution of data, the recognition efficiency will be greatly reduced.It is necessary to give an algorithm to regognize the abnormal areas on contour map of apparent resistivity using the computer, thus reduce the cost of recognition time. Recognition algorithm needs on the premise of contour map generation algorithm, this paper mainly research on the contour map generation algorithm based on TIN (Triangular Irregular Network). The execution efficiency of the building algorithm of TIN and the algorithm of drawing contour line at this stage need to be improved, and the accuracy and efficiency of the color contour map filling algorithm also has room for increasing. In this paper, these algorithms are improved, the automatic recognition algorithm of abnormal areas is gived, and the transient electromagnetic method is used as a geophysical exploration method to collect the data of apparent resistivity of geologic body, the main research contents as follows:(1) improved the the algorithm of buiding D-TIN (Delaunay Triangular Irregular Network) of the planar discrete data points and the algorithm of drawing contour line based on D-TIN, improved the algorithm of filling color of the contour map through the depth first search ideas, and verified the feasibility and effectiveness of the algorithm through experimental tests, smoothed contour map using the three times Bezier curve thoughing known points, drawn the contour map with inverse distance weighted interpolation algorithm;(2) separated the target anomaly areas of apparent resistivity taking advantage of the corresponding relationship between apparent resistivity values and the colors and using the binarization method, and recognized the locations, areas, shape characteristics of the abnormal areas with the OpenCV image library;(3) maked geophysical exploration experiments of water body, and maked geophysical exploration experiment of Yaozhan transformer substation in Lufeng county of Chuxiong prefecture of Yunnan with transient electromagnetic method, generated the contour map of the datas of apparent resistivity of these experiments and recognized the abnormal areas using the algorithms gived in this paper.