本研究以新造林及混農林坡地為調查對象，對微地形起伏、土壤厚度、大地比電阻、表 層土壤含水率等空間分布進行量測，並加上調查樣區周遭所發生的淺層崩塌調查概況，用以評估 新造林及混農林坡地水文地質敏感區域的分布，以及潛在的影響因素。結果顯示新植樣區及混農 樣區的坡度、土壤厚度的空間分布相似，兩樣區的坡度多集中於40~55%區間，土壤厚度多集中於 0.5~0.9 m區間，依照「山坡地土地可利用限度分類標準」及土壤有效深度之定義進行土地利用限 度分類，全樣區中僅有35%區域可直接列為宜農牧地。且若考慮周遭有淺層崩塌的發生實例，在成 林或是坡地穩定前，樣區中半數以上的區域宜分類為加強保育地，不宜農業開發，並需加強土水 保持措施。除了水文地質敏感區域的環境條件外，受到作業道路、灌溉明管暗管、灌溉灑水、雜 草抑制蓆鋪設等人為影響，導致土壤水集中在局部區域，降低局部區域的坡地穩定性，其影響遠 高於目前新植樣區或是混農樣區植生所增加坡地穩定性的效益。

This study measured spatial distributions of topography, soil depth, electrical resistivity, and surface soil water content and investigated the general situation of shallow slope failures in study sites to evaluate hydro-geological sensitive area and related factors on agro-afforested and afforested hillslope sites. Information of shallow slope failures occurred at and nearby observation sites additionally helped to identify characteristics of hydro-geological sensitive area. The results indicated that agro-afforested and afforested slopes had similar spatial distribution and soil depth. Slopes of both study sites distributed on the interval of 40〜55%; soil depth distributed in the range of 0.5〜0.9 m. Following the criteria in “Land use capability classification of slopelands” and “definition of effective soil depth”，only 35% of study area could be classified into land use for agriculture or animal husbandry. Additionally，due to the occurrences of shallow slope failures, study site should be carefully taken soil and water conservation into account. Artificial impacts such as agricultural roads，water pipes，irrigation，and weed sheets greatly affected local concentration of soil water, which potentially reduced slope stability. This study showed clear information that artificial impacts have greater implications than vegetation impacts for hillslope hydrological processes and slope stability.