以國土保育觀點探討坡地利用合理性

A Study of Rationality of Slopeland Use in View of Land Conservation

王兆文(Chao-Wen Wang) ； 沈哲緯(Che-Wei Shen) ； 林俐玲(Li-Ling Lin)

《農業工程學報》 59卷1期 (2013/03) Pp. 67-76

https://doi.org/10.29974/JTAE.201303_59(1).0005

摘要

1976年公布山坡地保育利用條例，係以規範山坡地範疇，為管理山坡地農地資源狀況，乃訂定「山坡地土地可利用限度分類標準」，將山坡地依其平均坡度、土壤有效深度、土壤沖蝕程度及母岩性質等四項因子，區分宜農牧地、宜林地及加強保育地，依照四項因子條件全面查定山坡地土地可利用限度分類。惟現行查定土地多為宜林地或宜農牧地，零星分佈結果造成土地破碎化且破壞景觀生態等問題，尤其易致災潛勢地區之查定土地，當颱風豪雨來時，對國土保安具有立即性危害。研究案例選用濁水溪流域為範圍，以集水區為分析單元，選取總曲率、平均坡度、平均高程、水力沖蝕指數（Stream Power Index, SPI）、坡向標準差、土地利用現況及常態化差異植生指標（Normalized Difference Vegetation Index, NDVI）等7項易致災影響因子，運用羅吉斯迴歸方法建立易致災潛感模型，透過誤差矩陣得知總體準確率達87.1%。再透過群集分析法建立濁水溪流域易致災潛勢分級成果圖，進而以國土保育觀點探討山坡地土地可利用限度查定標準之合理性，作為政府修訂坡地土地利用相關法規之參考。

關鍵字

山坡地土地可利用限度 ； 國土保育 ； 羅吉斯迴歸 ； 易致災區 ； 群集分析

並列摘要

Promulgated in 1976, ”Slopeland Conservation and Utilization Act” aims to regulate the scope of slopelands. ”Classification standard of slopeland utilization limitations” was set forth, classifying slopelands into land suitable for agricultural, animal husbandry or forestry purposes or as land subject to strengthened conservation according to their average slope, soil depth, soil erosion degree and parent rock. Overall inventory was carried out based on the said 4 factors to verify the classification standard of slopeland utilization limitations. However the currently verified lands are mostly suitable for forestry or for agriculture and animal husbandry. Scattered allocation of these lands results in critical issues such as segmented landuse and impaired landscape and ecotype. Especially for lands verified as disaster-prone, they are immediately harmful to land conservation when typhoon or heavy rain occurs.Jhuoshuei River is selected as the scope of the case study, using watersheds as analysis units. Seven vulnerability factors are selected, namely total curvature, average slope, average elevation, SPI, standard deviation of aspect, land use and NDVI in companion with a model of disaster susceptibility created based on logistic regression. Via error matrix, the overall accuracy of the training results is 87.1%. Subsequently the diagram disaster potential classification results of the Jhuoshuei River is created via cluster analysis. The study is mainly about discussions on the rationality of current slopeland and utilization limitations from the preservation view points of national lands. For the purpose of being referenced for revising statutory regulations of slopeland utilization limitations in the future.

並列關鍵字

Slopeland Utilization Limitations ； Land Conservation ； Logistic Regression ； Disaster-prone area ； Cluster Analysis