礫石地土壤水分移動之研究

Soil water movement for gravelly soil

王建涵(Wang Chien-Han)

指導教授 ： 吳嘉俊

國立屏東科技大學/工學院/水土保持系所/碩士(2012年)

https://doi.org/10.6346/NPUST.2012.00283

摘要

本研究利用野外試驗進行自然降雨下之礫石地土壤內的水分含量監測，以瞭解礫石含量對土壤水分含量變化的影響，並藉著田間土壤入滲試驗結果，推估礫石地土壤之飽和水力傳導度。
本研究發現，臨前降雨會影響土壤水分入滲速率，若臨前降雨間距時間短，土壤呈濕潤狀態，土壤內水分在降雨初期較容易傳遞。研究結果顯示，土壤中的礫石控制了土壤的結構性質，水分容易從顆粒間的粗孔隙入侵至土體中。為便於實務應用，根據實驗所得原土壤之飽和水力傳導度(K0)與礫石重量百分比(a)，本研究含礫石土壤之田間飽和水力傳導度(K*)推估如下:
K*=[(0.1925×a)-7.5962]×K0
本研究並嘗試以降雨量減去入滲量，並配合土層間水分傳遞速率之田間試驗結果，推估田間逕流量的產生。由推估結果顯示，土壤內的礫石會直接影響水分的入滲歷程，進而影響逕流量的產生，地表逕流量隨土壤中礫石含量的增加而減少。

關鍵字

礫石地飽和水力傳導度 ； 土壤水分移動 ； 地表逕流量推估

並列摘要

The objective of this study is to investigate how gravel content affects the infiltration proess and soil moisture flucutations through field experiments on a gravelly slope.
This study found that antecedent rainfall will affect soil infiltration rate. Shorter the time break between storms, wetter the soil matrix; therefore, soil moisture can easily propergate in soil profile at the beginning of the storm. The experimental results showed that the existence of gravel in soil matrix alters the structural properties of the soil, which makes water easily intrude through the coarse pores between soil particles. To facilitate practical application, in-situ saturated hydraulic conductivity (K*) estimattion equation was obtained based on saturated hydraulic conductivity (K0) of the original soil and gravel content by weight (a):
K*=[(0.1925×a)-7.5962]×K0
This study undertook the effort of estimating runoff hydrograph by subtracting the infiltration histrogram from rainfall hyetograph while using the in-situ soil moisture transport rates between soil layers to control the propergation of the soil water. Estimation results indicated that the presence of gravel affects the infiltration process directly, and that also affects the runoff production. The estimation results furthermore showed that runoff production decreases as gravel content by weight increases.

並列關鍵字

Saturated hydraulic conductivityof gravelly soilSaturated hydraulic conductivityof gravelly soil ； Soil water movement ； Runoff production estimation

參考文獻

23.黃昭蓉，2010，礫石地逕流係數與入滲現象之研究，碩士論文，國立屏東科技大學水土保持系，屏東。

31.鄧屬予，1996，「台灣卵礫石層的地質背景」，地工技術，55:5-24。

28.褚炳麟、潘進明、張國雄，1996，「台灣西部卵礫石層現地之大地工程性質」，地工技術，5:47-58。

17.陳明杰、黃襦慧，2006，「張力滲透計應用於蓮華池五號集水區土壤水力傳導度測定分析」，中華林學季刊，39(2):207-220。

25.黃國禎、江介倫、黃彥凱、邱宏彬、黃瀞瑩，2009，「老埤台地不同植生下土壤孔隙特性之研究」，農業工程學報，5(2):81-94。