飛濺沖蝕量估算公式之研發

水蝕始於雨滴的撞擊，雖然雨滴粒徑所代表的降雨沖蝕潛能、土壤機械組成與團粒穩定度所代表之土壤沖蝕性看似相互獨立，但兩者之間的交叉影響，甚至土壤體積水分含量，關係著飛濺沖蝕的發展與飛濺沖蝕量的多寡。本研究利用水滴產生器，在不同土壤體積水分含量及土壤機械組成情況下，探討水滴粒徑、土壤體積水分含量，以及土壤機械組成與團粒穩定度對飛濺沖蝕量之影響。研究結果顯示，飛濺沖蝕量與水滴粒徑、修正版顆粒粒徑參數、土壤體積水分含量及水團粒穩定度具有高度相關。藉由迴歸分析，本研究進一步獲得飛濺沖蝕量估算公式，調整後之判定係數（adjusted coefficient of determination）R^2達0.804，各參數皆達顯著水準。

關鍵字

飛濺沖蝕；水滴粒徑；土壤體積含水量；土壤性質；水團粒穩定度

並列摘要

Water erosion starts with raindrops impact. Raindrop impact (which reflects the erosivity of precipitation) has been treated as independent mechanism with respect to the constitution of primary particles and stability of soil aggregate (which characterizes soil erodibility), but they interact; even volumetric soil water content may affect the process as well as the amount of soil loss from splash erosion. This study uses waterdrop generator to study the splash erosion at different volumetric soil water contents and soil properties. Results indicate that amount of splash erosion is highly correlated with waterdrop diameters, modified particle-size parameter, volumetric soil water content, and water aggregate stability. A splash erosion estimation equation was developed, in which all principal physical parameters were embedded, the adjusted coefficient of determination R^2 reaches 0.804, and all parameters reach statistic significant level.

並列關鍵字

Splash erosion ； Waterdrop diameter ； Volumetric soil water content ； Soil properties ； Water aggregate stability

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