為瞭解近地表的入滲現象,可使用間接的地球物理測量或利用直接水文量測如含水量或張力進行分析。單獨使用地球物理測量測量雖可提供高密度地下圖像，但圖像和含水量間的關係卻不明確；反之，若是單獨使用水文量測數據分析，雖然可以清楚表達水文數據和流體運移之關係，但通常空間上的涵蓋範圍較小。結合兩種方法，可彌補彼此之間的缺點，可提高量測結果的密度與可靠度。本研究主要目的是利用現地試驗方法，嘗試結合自然電位與直接水分含量量測，描述淺層地表的入滲行為。本研究選定一實驗場址，現地試驗前先進行自然電位與水分含量計對現地土樣之水分含量率定實驗，並取得該率定曲線。實驗場址則設置共48支電極，量測入滲環定水頭入滲期間電位資料分佈，場址內另置一水分含量計記錄水分含量。入滲過程電場資料與單點之水分含量資料再依據電場與水分含量率定曲線反推，可得入滲過程全區域之水分含量分布。此入滲過程的水分含量分佈再與FEMWATER數值模式結果比對，評估觀測結果之合理性。研究結果顯示，實驗室土樣量測電位差與水分含量呈線性負相關，現地電位量測可反映入滲過程中，水由入滲環向外擴散現象，但因場地外部電場干擾大，使得結果不明顯。;Typical approaches to assess the infiltration can use either the geophysical surveys or hydraulic tests such as the measurements of water content or pressure. The geophysical survey such the self-potential method can map electrical properties of soils with high resolution. However, the variations of soil hydraulic properties are not available by using solely the geophysical observations. Measurements of water content can directly reflect the infiltration behavior but the number of measurements is usually limited. This study aims to integrate self-potential and water content measurements to assess the infiltration behavior of a single ring constant head test. A small test site was considered for the infiltration test. The soil samples of the site were used to create a rating curve for self-potential and water content measurements. To measure the voltage variation during the infiltration test, the study installed 48 probes with constant interval of 0.5m in the test site. A water content probe was used to directly measure time series of water content during the test. Based on the rating curve obtained from soil samples in the laboratory test, the voltage variations at the location of the water content probe were then use to map water content distributions for the entire test site. This study then used the FEMWATER numerical model to evaluate the water content distributions for the infiltration test. Results of the laboratory test showed that the voltage differences linearly correlate with the variations of the water content. Field-scale self-potential measurements can reasonably reflect behavior of single ring infiltration test. However, the variations of the voltage variations are not clear due to the complex disturbance sources near the test site.
