利用電磁波探測土壤坡度之研究

THE STUDY OF USING ELECTROMAGNETIC WAVE FOR DETECTING THE SLOPE OF THE SOIL

吳偉成(Wei-Cheng Wu)

指導教授 ： 劉格非

國立臺灣大學/工學院/土木工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.00038

摘要

台灣坡陡流急地質碎弱，加上民國88 年921 地震後土質鬆軟，
接著象神、桃芝及納莉颱風的豪大雨造成許多人員傷亡，往往一場豪
雨下來便傳出許多災情，而近年來發生土石流的災害頻繁，如何預警
及事先疏散人群為現在主要議題。本文嘗試以微波遙測技術進行土壤
坡度的偵測，原本的層狀介質中，所有層與層之間的界面都是平行
的，但是在實際的地層當中，層與層之間的界面相較於地表面可能有
一極小的坡度，因此以微擾法(perturbation method) 去解出符合現實
地形及地層的傾斜狀況，借以電磁波照射傾斜地表，從反射訊號去判
斷每層土壤坡度之可行性。
微波在土壤中的傳播行為受土壤的介電常數影響，土壤的介電常
數亦決定雷達的訊號速度、衰減和能量，每層土壤以麥克斯威爾方程
式(Maxwell equation)為控制方程式，接著以層狀介質法(stratified
media method)及微擾法來模擬電磁波照射在不同介電常數的介質之
反射波。最後藉由一室內的砂箱實驗所得到的反射訊號來和理論所推
得的解析解作比較，來瞭解實際上微波探測可得到的值與理論值的差
距，以便設計現場微波探測土壤坡度的系統。
由解析解與實驗值可得知預測角度誤差值可以控制在2 度以內，
這樣的結果尚可接受，實驗部分驗證理論推導所得到的解析解外，進
而可以應用解析解來反推土壤坡度，在現地探測土壤坡度上有很大的
幫助。在現地上的應用要注意的是理論推導適用於微擾角度，一旦坡
度過大則此理論解將不適用，由預測角度誤差值中也可以發現角度在
9 度或10 度誤差值都滿大的。由解析解也可知道當入射角越大時，
其判釋角度差異性的能力越差。

關鍵字

麥克斯威爾方程式 ； 無因次分析 ； 微擾法 ； 層狀介質法

並列摘要

This text tries to carry on the detecting and examining of the slope of soil with microwave remote sensing measurement technology, in the original layers of forms medium, all layers and interface between layer is parallel, but in the real stratum, layer with interface than have one little slope extremely on ground surface looks of layer, so use as perturbation method to solve the slope state which accord with realistic topography and stratum , illuminate in the sloping earth's surface, the feasibility going to judge the slope of each layer soil from the signal of reflecting for the electromagnetic wave.
The transmitting behavior in the soil of microwave is influenced by dielectric constant of the soil, the dielectric constant of the soil also determines the speed of signals, decays and energy of the radar, each layer soil is with Maxwell equation preface as the governing equation, and then uses stratified media method and perturbation method to imitate the reflection wave of the electromagnetic wave which shines on the medium of different dielectric constants. The reflection signal is got by an indoor sand box experiment and the analytic solution is deduced from theory and made comparisons finally, to understand the difference between the value that the microwave is surveyed and the theory value in fact, system in order to design a site for using the microwave to survey the slope of soil.

並列關鍵字

Maxwell equation ； Normalization analysis ； Perturbation methods ； Stratified media method

參考文獻

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