臺灣在過去60年間山坡地產生大量的景觀變遷,山坡地土地使用的改變帶來越多的衝擊。根據文獻回顧指出臺灣山坡地政策始於退輔會農業開墾政策,安置榮民於山坡地上進行農墾,而後有農地放領政策的發展觀光階段與差異化策略階段,至今執行國土復育政策。山坡地政策可能影響山坡地土地使用,並且土地使用的改變可能帶來環境與社會衝擊。因此,本次研究目的主要探討退輔會農業開墾政策、農地放領政策的發展觀光階段與差異化策略階段、國土復育政策帶來的土地使用變遷,以及土地使用變遷帶來的環境與社會變遷衝擊。 研究對象挑選採用歷史自然試驗方法挑選出退輔會福壽山農場、武陵農場與清境農場三座高海拔農場進行分析。由於農地放領政策將土地分成公家土地與私人土地,進一步了解山坡地政策在公私有土地上景觀變遷的影響。研究依據各政策時期以航照圖進行土地使用分析,將土地使用分成森林、農地、建地與道路進行分析,依據環境衝擊指標說明土地使用帶來的環境衝擊,以森林破碎化指標了解棲地破壞狀況,並以空間自相關分析探討增加的森林、農地與建地是否具有群聚的狀況。研究輔以質性內容分析法,評估山坡地開發帶來的環境衝擊與社會衝擊之間的因果關係。 研究結果指出社會變遷下的山坡地農場農業開墾政策減少森林並增加農地面積帶來農業經濟效益,其中農業開墾也開始帶來土石崩塌現象,並對水庫造成淤積和水源汙染問題。農地放領政策時期農地帶來土石崩塌、水源汙染、生態破壞環境衝擊,道路帶來大量土石崩塌。其中在差異化策略階段上,福壽山農場與武陵農場開始廢耕返林增加森林與減少農地,清境農場則以發展觀光民宿為策略,開始大量增加民宿建地,確實帶來觀光經濟效益,但過多的民宿卻產生交通阻塞、用水不足等社會衝擊。此外,也發現道路開發吸引民宿建地聚集,而民宿建地又產生私人道路出現,山坡地道路建設影響山坡地景觀變遷甚鉅。國土復育政策時期在三座農場的公家土地上增加森林並減少農地,有助生態保育減緩水源汙染之效益,但可發現仍有農業帶來的環境衝擊問題,顯示農地所佔比例可能仍過高。
There have been many landscape changes, land use changes, and impacts regarding the slopeland of Taiwan over the past 60 years. The slopeland use policy began with the Veteran Agricultural Policy from the Veterans Affairs Council in Taiwan. The Farmland Release Policy and National Land Restoration Policy appeared afterwards. The Farmland Release Policy included two stages: tourism development and a differentiation strategy after the 921 earthquake. Land use changes may be affected by the slopeland use policy and cause environmental and social impacts. Therefore, the purpose of this study is to explore the effects of policy changes, including those of the Veteran Agricultural Policy, Farmland Release Policy, and National Land Restoration Policy, on landscape changes and environmental and social impacts. Three high-altitude farms (Lishan, Wulin, and Cingjing Farms) were selected through natural experiments of history. We used land use analysis to analyze forest land, agricultural land, construction land, and roads through the aerial maps. We also analyzed the effects on public and private land after the Farmland Release Policy was implemented. Environmental impact indexes and fragmentation analysis were used to explain the environmental impact. Spatial autocorrelation was used to explore the land use patterns of diffusion. Qualitative content analysis was used to explore the relations between land use and environmental and social impacts. The results showed that the Veteran Agricultural Policy increased agricultural land, brought agricultural economic benefits, and caused landslides, reservoir deposits, and water pollution. Agricultural land from the Farmland Release Policy also caused landslides, water pollution, and ecological damage. Lishan and Wulin Farms implemented the afforestation strategy and increased forests in the differentiation strategy stage after the 921 earthquake. Cingjing Farm implemented the B & B strategy and increased a large amount of construction land and number of private roads. Cingjing Farm obtained tourism economic benefits and experienced traffic jams and water shortage problems. The National Land Restoration Policy increased forests on public land, led to ecological restoration, and reduced water pollution. However, there are still some environmental impacts from agricultural land. The proportion of agricultural land may still be too high on the three farms.