臺灣東部山坡地土壤沖蝕性指數之建立與分布

鑒於臺灣目前所參考之土壤沖蝕指數（soil erodibility, K factor）乃於30餘年前建立，距今已久遠，加上近年來，氣候變遷引起諸多嚴重坡地災害，同時，近年山坡地過度開發且土地利用變化差異甚大，顯示土壤沖蝕指數極具有重新建立與評估之必要性。本研究主要於宜蘭縣、花蓮縣及臺東縣山坡地範圍內（海拔高程為100 m至1000 m），於各縣市選取最具代表性之30個基標土系（benchmark soil series），建立該地區K值之數值與繪製空間等值分佈圖。本研究採Wischmeier et al. （1978）公式計算各縣市山坡地基標土系之K值，並以克利金推估模式（Kriging interpolation model）繪製空間分布等值圖，以提供水土保持相關從業人員之參考。本研究結果顯示，宜蘭縣山坡地K值為0.0108-0.0671 t．ha．yr．ha^(-1)．MJ^(-1)．mm^(-1)，花蓮縣山坡地K值為0.0268-0.0829 t．ha．yr．ha^(-1)．MJ^(-1)．mm^(-1)，而臺東縣山坡地K值為0.0172 - 0.0533 t．ha．yr．ha^(-1)．MJ^(-1)．mm^(-1)，結果指出以花蓮縣山坡地土壤沖蝕潛勢較高。本研究調查之K值分佈與萬鑫森與黃俊義（1989）之K值分佈具有顯著差異，以宜蘭縣東邊、花蓮縣南邊及臺東縣北邊山坡地提升最顯著，K值由1989年的0.013增加至2016年的大於0.039，推測坡地受災害嚴重擾動與土地開發之影響所致。

關鍵字

土壤沖蝕性指數；基標土系；空間分布；土壤沖蝕潛勢

並列摘要

Soil erodibility factor (the K factor) should be re-established due to soil properties have been obviously influenced by climate change and over developed of slopelands in recent years in Taiwan. The old K factor developed by Wann and Huang (1989) used in Taiwan might not be suitable longer because it has already established thirty years at least. This study selected 30 benchmark soil series in sloplands (100 m- 1000 m) for each county (Yilan, Hualien and Taitung) in eastern Taiwan to analyze surface soil properties and calculated the K factors (based on Wischmeier et al. (1978)) and its spatial distribution. The results revealed that the K factors were 0.010-0.073 t．ha．yr．ha^(-1)．MJ^(-1)．mm^(-1) in Yilan, 0.021-0.082 t．ha．yr．ha^(-1)．MJ^(-1)．mm^(-1) in Hualien and 0.0076-0.050 t．ha．yr．ha^(-1)．MJ^(-1)．mm^(-1) in Taitung. Higher soil erodibility was found in the slopelands in Hualien. Comparing with the results from Wann and Huang (1989), new K factors obviously larger at eastern Yilan, and at southern Hualien, and northern Taitung, which might be attributed to serious disturbance of soils by climate change or long-term change processes of land uses.

並列關鍵字

soil erodibility ； benchmark soil ； spatial distribution ； soil erosion potential

國際替代計量

臺灣東部山坡地土壤沖蝕性指數之建立與分布

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