敷蓋及擾動土壤對建立緩坡草地期間地表逕流之影響

Effects of Mulching and Disturbance of Soil on Runoff Parameters during the Period of Pasture Establishment in Gentle Slopeland

謝昭賢(Chao-Hsien Hsieh) ； 鄭皆達(Jie-Dar Cheng) ； 蘇瑞榮(Ruey-Rong Su)

《中華水土保持學報》 30卷3期 (1999/09) Pp. 181-193

https://doi.org/10.29417/JCSWC.199909_30(3).0002

摘要

本試驗利用小型模擬降雨機來評估敷蓋及擾動土壤對建立緩坡草地期間地表逕流之影響。本試驗以2×2複因子設計，3重複，共12個1×0.5×0.8 m^3之土箱。試驗因子爲敷蓋因子（含敷蓋及裸露處理）及擾動因子（含擾動及無擾動處理）。本試驗在模擬降雨強度50 mm/h下，同一處理進行30 min之乾土測定，中斷30 min後，再進行60 min之濕土測定。所得之逕流資料用以分析（1）起始逕流時間：（2）逕流上升肘之斜率變化：及（3）平衡逕流率之斜率變化。本試驗二參試因子對建立緩坡草地期間逕流參數之影響爲：在乾土測定中，同一敷蓋因子下，敷蓋處理較裸露處理可延遲69.4％之起始逕流時間、降低18.5％之上升肘之逕流迴歸係數、降低26.8％之終端逕流量及降低28.9％之平均逕流率；及在同一擾動因子下，擾動處理較無擾動處理可延遲375％之起始逕流時間、降低56.9％之上升肘之逕流迴歸係數、降低104％之終端逕流量、及57.3％之平均逕流率。在濕土測定中，同一敷蓋因子下，敷蓋處理較裸露處理可降低19.1％之尖峰流量、降低12.2％之終端逕流量及降低28.9％之平均逕流率；及在同一擾動因子下，擾動處理較無擾動處理可降低40.8％之尖峰流量、降低57.3％之平均逕流率及降低36.9％之終端逕流量。由本試驗結果建議建立緩坡草地時，擾動處理與敷蓋處理可延遲起始逕流時間、減低逕流上升肘之斜率及降低尖峰流量。但本試驗僅在坡度5％，降雨強度50 mm/h，降雨延時60 min之限制，應用本試驗之結果時，應避免在降雨強度高及降雨延時長之雨季。

關鍵字

逕流水文圖 ； 模擬降雨 ； 敷蓋 ； 擾動

並列摘要

A small-scale rainfall simulator was used to evaluate the effects of mulching and disturbance of soil on runoff parameters during the period of pasture establishment in gentle slopeland. The 2×2 factorial experiment design with three replications was employed. One factor was coverage with mulching or bare treatment, and the other was disturbance factor with disturbed or undisturbed treatment. A 50 mm/h rainfall simulation consisted of two phases, a dry run of about 30 min followed by a wet run. Runoff hydrographs (runoff / applied water × 100) were subdivided into three components representing: (1) time to runoff initiation; (2) rate of change in runoff percentage in the rising limb; and (3) equilibrium runoff percentage. Under the same coverage factor on the dry run conditions, the runoff initiation time was delayed for as much as 69.4%, the regression coefficient of runoff rising limb was deflated 18.5%, the final flow was lowered 26.8%, and the average runoff rate was reduced 28.9% for the mulching treatment as compared to those for the bare treatment. Under the same disturbance factor, the runoff initiation time was delayed for as much as 375%, the regression coefficient of runoff rising limb was deflated 56.9%, the final flow was lowered 104%, and the average runoff rate was reduced 57.3% for the disturbed treatment as compared to those for the undisturbed treatment. Under the same coverage factor on the wet run conditions, the peak flow was lowered as much as 19.1%, the final flow was lowered 12.2%, and the average runoff rate was reduced 28.9% for the mulching treatment as compared to those for the bare treatment; and under the same disturbance factor, the peak flow was lowered 40.8%, the final flow was lowered 57.3%, and the average runoff rate was reduced 57.3% for the disturbed treatment as compared to those for the undisturbed treatment. The results suggest that the combination of disturbed and mulching soil can reduce runoff fate and peak flow in gentle slopeland. However, the results to the season with high rainfall intensity and long storm duration should be avoided.

並列關鍵字

runoff hydrograph ； simulated rainfall ； mulching ； disturbed soil