"隨著人口日益增加的同時也造成了地球資源匱乏的壓力，水資源的永續利用及環境污 染議題的探討已成為許多專家學者的首要任務。在未飽和層土壤研究方面，受限於量 測資料數量、地質構造異質性、經費、時間、技術能力等因素，導致在掌握未飽和層 土壤內之流體流動特性及污染物傳輸途徑上遭遇相當大的困難。為深入瞭解未飽和土 壤流體流動特性及污染物傳輸機制，準確、快速且大量的量測現地土壤水文參數及污 染物濃度資料，將扮演極為重要之角色。因此，本研究驥望藉由室內砂箱實驗與野外 現地土壤入滲試驗，進行 TDR非破性量測技術之發展，針對未飽和層土壤含水量、張 力水頭、水力傳導係數等水文地質參數，分析其在時間與空間之變化並探討遲滯效應 對量測結果之影響。此外，本研究亦將針對 TDR污染物濃度監測技術進行室內污染物 傳輸實驗，藉由 TDR量測數據分析污染物濃度分佈及其傳輸途徑。經由室內與現地之 量測數據，建立未飽和層流體與污染物傳輸數值模式，利用數值模式優化之技巧，進 行模式之率定，找尋最佳水文與污染物參數。經由本專題研究之執行，驥望可發展出 一套 TDR現地量測污染物濃度之標準流程，提供往後未飽和層土壤污染物傳輸分析與 污染物整治可行性評估之參考指引。 ""As an ever expanding population puts more and more pressure on the scarcity of Earth’s resources, research on sustainable use of water resources and substantial remediation of environmental pollutions undoubtedly will remain a high priority issue for many years to come. Within the aspect of unsaturated soil, because of insufficient measured data, heterogeneous soil structure, restricted budget, limited time, and immature investigating technologies, it is still a challenge to characterize the properties of groundwater flow and identify the mechanisms of solute transport in the unsaturated zone. Therefore, in order to understand the characteristics of unsaturated flow and associated mechanisms of solute transport, collecting numerous hydrological data and contaminant concentrations accurately and efficiently has become a crucial issue. In this study, the time domain reflectometry (TDR) technique, a non-destructured approach, will be developed to measure volumetric water contents in the laboratory and applied to the soil infiltration test at the field. The laboratory experiments will focus on the relations between soil water content, pressure head, and unsaturated hydraulic conductivity. The hysteresis effect on TDR measurements will be also addressed. Besides, the TDR technique will be applied to measure contaminant concentrations in a dynamic sand box in the laboratory and the results will be used to analyze the distributions of plume and the transports of contaminant. Based on the laboratory experiments and field tests, coupled unsaturated flow and transport models will be developed. The sensitivity analysis and automated parameter estimation method will be conducted on the model calibration. Finally, through a systematic design, careful experiment, and numerical simulation, a standard procedure for measuring contaminant concentration using the TDR technique will be established. The works developed in this study can provide as reference tools for contaminant site investigation and remediation assessment in the future. "
time domain reflectometry
soil water content