石塊覆輔v與放置方式對紋溝間土壤沖蝕之影響

The Effect of Cover Rate and Disposition of Rock Fragments on Interrill Soil Erosion

鍾宜全(Yi-Chuan Chung)

指導教授 ： 范正成

國立臺灣大學/生物資源暨農學院/生物環境系統工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.00598

摘要

本研究的主要目的在於研究石塊覆輔v及放置方式對紋溝間土壤沖蝕的影響，其間的關係，以及造成影響的原因。
本研究之沖蝕試驗採用林口地區的紅壤，在試驗箱內進行試驗，坡度固定為20%，利用天然的卵石塊鋪放在土壤表面作為覆貌哄A改變其覆輔v與放置方式，在兩種強度的人工降雨下進行沖蝕試驗。試驗的結果發現：一、石塊全部或部分裸露於土表時，可保護試體表面細顆粒土壤免於被雨滴直接撞擊，因此，其沖蝕較少。完全埋入試體之石塊，會降低土壤試體的滲透性，造成逕流率升高，形成較大的沖蝕。二、在不同的石塊放置方式、兩種降雨強度下，均以石塊全部露出的逕流率最小，也就是其入滲率最高，涵養水分的能力最好。以覆輔v為30%在低降雨強度時的效果最佳，逕流率只有23.87%。三、當覆輔v為60%時，排列之方式為石塊全部露出與石塊部分嵌入的情況下，對降低沖蝕之效果最佳；而石塊完全埋入則比未經處理之土壤更差。四、石塊放置方式對沖蝕之影響大致的趨勢為石塊全部露出的沖蝕量最少，其次是石塊部分嵌入，而石塊完全埋入卻反造成更多的沖蝕。
經由試驗數據整理分析，發現沖蝕量與覆輔v、覆貌囿漫騆m方式以及降雨強度有不錯的相關性。經由迴歸分析，得出關係式，其判定係數達到0.839。

關鍵字

放置方式 ； 降雨強度 ； 土壤沖蝕 ； 覆輔v ； 石塊 ； 紋溝間土壤沖蝕

並列摘要

The primary purposes of this study are to investigate the effects of cover rate and disposition of rock fragments on interrill soil erosion, the relationships among them, and the causes of these effects.
In this study, the soil used for erosion tests was the lateritic soil from Lin-Kou. Soil samples were placed in erosion boxes and the slope steepness was controlled to be 20%. Natural pebbles were used as rock fragments to cover the soil surface. Different cover rates and disposition of the rock fragments were used along with two rainfall intensities of simulated rainfall. Following results were obtained from the erosion tests. Firstly, when the rock fragments were completely or partially exposed on the soil surface, they could protect the fine particles on the soil surface from raindrop impact, and accordingly, the erosion was less. As for the rock fragments completely embedded into the soil, they tended to cause lower soil permeabilities. Subsequently, the runoff and erosion increased. Secondly, under the conditions of three different disposition methods of rock fragments and of two different rainfall intensities, it was found that while the rock fragments were completely exposed to the soil surface, the runoff coefficient were the least, i.e., the infiltration rates were the highest and water retention ability were the best. Among all the conditions, with 30% cover rate and 40 mm/hr rainfall intensity, the runoff coefficient had a smallest value of 23.87%. Thirdly, while the cover rate of rock fragment was as high as 60%, it was found that soil with rock fragments completely and partially exposed to the soil surface were the best, in reducing the erosion rate. Soil with rock fragments completely embedded into the soil was worse than soil without any treatment. Fourthly, regarding the effects of disposition methods on reducing soil erosion, it was found that the erosion of soil with rock fragments completely exposed to the soil surface was the least, followed by rock fragments partially exposed to the soil surface. With the rock fragments completely embedded into the soil, erosion was greater than soil that without any treatment.
Overall, it was found that erosion rate, cover rate, disposition of the rock fragments and rainfall intensity were well related. A regression equation, with a coefficient of determination of 0.839, were developed to relate these parameters.

並列關鍵字

rainfall intensity ； cover rate ； disposition ； soil erosion ； interrill soil erosion ； rock fragment

參考文獻

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