推估土壤傳輸參數現地試驗方法改進與數學模式發展

Improvements of the mathematical model and the In-Situ Method for Estimation of Transport Parameters in Soil

梁書嚴(Suu-yan Liang)

指導教授 ： 陳瑞昇

國立中央大學/地球科學學院/應用地質研究所/碩士(2012年)

摘要

土壤宿命傳輸模式為計算土壤污染物動態的重要方法，模式的可靠性取決於考慮相關傳輸過程是否適當，除了選擇合適的模式，模式所需輸入參數也非常重要，延散係數為數學模式重要輸入參數，而現地入滲追蹤劑試驗為同時決定土壤縱向與側向延散度之有效方法。現有的相關研究中數學模式常假設無窮大的出流邊界，此假設較不符合實際的情況。本研究將檢驗相關數學模式的適用性之外，並將前人提出無窮邊界之解析解改進為有限長度之解析解，且將兩者比較，若Peclet number較小時，利用無窮邊界之數學模式進行推估會低估土壤的延散係數。現地試驗方面經由多次改進儀器設計、操作過程與相關細節後，現地試驗所得獲得之濃度穿透曲線配合改進後的數學模式可推估試驗場地的縱向與側向延散參數。

關鍵字

延散係數 ； 現地試驗 ； 土壤

並列摘要

Fate and transport models to calculate transport in soils are increasingly being used in practice. The reliability of soil transport model calculations depends on the accuracy with which relevant processes for contaminant transport are implemented in fate transport model. Besides an appropriate model choice, the parameterization of the model also plays an important role. Dispersion coefficients are important parameters for soil fate and transport model. Field infiltration test with a tracer is a proposed technology for simultaneous determination of longitudinal and transverse dispersion coefficients in soil. Existing research of mathematical models assumed infinite boundary condition. When Peclet number is smaller, the concentration of infinite boundary will be lower. If use the analytical solution of infinite boundary condition to estimate the solution transport parameter, and therefore underestimate the dispersion coefficients. In Field infiltration test with tracer, experience obtained in this test is used to refine the apparatus designs, operational procedures and relevant details for the test. We used the concentration breakthrough curve of Field infiltration test with tracer to estimated longitudinal and transverse dispersion.

並列關鍵字

In-Situ Method ； soil ； despersion

參考文獻

ASTM, 2008. Standard Test Method for Infiltration Rate of Soils in Field Using Double-Ring Infiltrometer, Annual Book of ASTM Standards, 04.08, D 3385-09.

Barry, D.A., Sposito, G., 1988. Application of the convection–dispersion model to solute transport in finite soil columns. Soil Science Society of America Journal 52(1), 3–9.

Boesten, J., 2004. Influence of dispersion length on leaching calculated with PEARL, PELMO and PRZM for FOCUS groundwater scenarios Pest Management Science, 60(10), 971–980.

Bromly, M., Hinz, C., Aylmore, L. A. G., 2007. Relation of dispersivity toproperties of homogeneous saturated repacked soil columns. European Journal of Soil Science, 58(1), 293-301.

Chen, J.S., Chen, J.T., Liu, C.W., Liang, C.P., Lin, C.M., 2011a. Analytical solutions to two-dimensional advection–dispersion equation in cylindrical coordinates in finite domain subject to first- and third-type inlet boundary conditions. Journal of Hydrology, 405(3-4), 522-531.