紅壤土之入滲試驗及參數推估

The Laterite Infiltration Test and Parameter Estimation

張德鑫(Te-Hsing Chang) ； 梁庭維(Tin-Wei Liang)

《農業工程學報》 57卷4期 (2011/12) Pp. 37-48

https://doi.org/10.29974/JTAE.201112.0004

摘要

桃園地區土壤多為第四紀紅壤土與礫石之沉積，其中紅壤土為不易入滲介質，顆粒小且易吸附水份，紅土於入滲過程中常因吸水膨脹後降低孔隙率而造成入滲率快速下降，因此本研究針對桃園地區紅壤土進行環筒入滲識驗，探討其不同情況下之入滲行為。研究中先進行一般物理試驗，可得紅土比重約為2.61、乾土單位重約1.65 g／cm^3，及其坋、黏土比例約為4：6；現地取樣進行滲漏試驗求得紅土之飽和水力傳導係數約為3.22 mm／hr。根據環筒入滲試驗可知紅土穩定入滲率約為4.88 mm／hr，其值略大於飽和水力傳導係數，主要原因為入滲試驗中之初始水頭與土壤吸水勢能所致。本研究針對Kostiakov（1932）、Mezencev（1948）及Horton（1940）三種不同入滲經驗式進行紅土之入滲推估式適用性探討，得知Kostiakov經驗式僅適用於紅土起始含水量低之短期入滲，Mezencev經驗式於紅土入滲擬合度最佳，Horton經驗式於表土初始含水量較高情況亦有不錯之擬合。

關鍵字

入滲 ； 現地試驗 ； 紅土

並列摘要

Most soil in Taoyuan area is laterite and gravel. But the laterite is not the good porous medium of infiltration, and it is small and easy to absorb water. During the infiltration process, the inflation causes the obstruction between soils. The more water of soil, the smaller of soil pore, and the infiltration rate drops dramatically. Therefore this research using the infiltration experiment in laterite and discusses its phenomenon. The beginning of this research analyzes the sample of laterite. The average weight of laterite is 2.61, the unit volume of dry soil is 1.65 g/cm^3 and the silt and clay proportion is approximately 4:6. According to the lab leakage instrument experiment, the final infiltration rate (4.88 mm/hr) is slightly bigger than the saturated hydraulic conductivity (3.22 mm/hr). Because the final infiltration more than deposit and capillary potential head. In the end of this research, three different infiltration equation models Kostiakov (1932), Mezencev (1948) and Horton (1940) were used to analyze the infiltration apply of laterite. Generally speaking the Kostiakov equation is better to be applied in short time infiltration especially for dry soil. The Mezencev equation has lots of similarity in laterite infiltration, and the Horton equation is also good for simulation of initial infiltration especially for wet soil.

並列關鍵字

Infiltration ； Field test ； Laterite