應用透地雷達於土壤飽和度與地下水位調查之研究

Application of ground penetrating radar to evaluate the degree of saturation of moist soil and the depth of water table

蔡士弦(Shin-Hsien Tsai)

指導教授 ： 林商裕 ； 蔡佩勳

朝陽科技大學/理工學院/營建工程系/碩士(2010年)

摘要

本研究之目的在利用透地雷達來探測地下水位與土壤飽和度對雷達影像圖之影響，於模型箱填入不同土壤來進行試驗並採用1GHz之透地雷達天線頻率，配合RAMAC Ground Vision與MATLAB軟體來辨識影像圖。在地下水位的試驗中，以透地雷達來探測五種不同地下水位之影像圖，以建立雷達對地下水位辨視之經驗。在土壤飽和度試驗中，以六種不同飽和度的土壤之雷達影像圖來計算不同飽和度下之雷達波波速，並討論介電常數與飽和度之關係。同時在本試驗中也將埋設鋼筋與鐵管之目標物以了解不同土壤飽和度下，此兩種目標物之倒V影像的變化。
由本研究之結果:發現雷達影像圖可輕易地辨視地下水位面，因其有明顯的斷折影像特徵。本研究採用DC濾波、水平濾波、平均濾波、增益處理等濾波方式，有助於判別地下水位之位置。隨著土壤含水量(或飽和度)的增加，目標物(鐵管與鋼筋)的倒V影像越愈彎曲，且土壤之介電常數與其含水量或飽和度呈二次函數之關係。

關鍵字

濾波處理 ； 土壤飽和度 ； 地下水位 ； 透地雷達

並列摘要

The purpose of this study is used ground-penetrating radar to detect the location of water table and study the effect of the degree of saturation of soil on the GPR image. In the model test, 1GHz ground-penetrating radar antenna with the RAMAC Ground Vision and MATLAB software was used to result in GPR images. In the study of water table detected, five depths of water table were set up in sand box. Then the depth of water table will be determined from the GPR images. The influence of six saturation degrees of soil with two target embedded in on GPR image soil were obtained by evaluating the relationship between dielectric constant and the degree of saturation. The radar of reflected signals due to target embedded are used to study the influence of the degree of saturation of soil and target on the GPR image.
From the results of this study, it can be observed that the depth of water table can be determined from GPR image. The relationship between the dielectric constant of soil and the degree of saturation is a quadratic formula. The radar reflected image of target (steel pile and steel bar) is sharper as the degree of saturation of moist soil increases.

並列關鍵字

water table ； Filter ； Ground Penetrating Radar ； Soil saturation

參考文獻

9. 王佳彬，「透地雷達在地下水調查、監測與整治之應用」，石油季刊，第40卷，第二期，第27~36頁，2004。

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