集水區坡面泥砂產量推估模式建立之研究

Model Establishment for Estimating watershed-scale Sediment Yield on Slopeland

林文賜(Wen-Tzu Lin) ； 林昭遠(Chao-Yuan Lin) ； 周文杰(Wen-Chieh Chou) ； 黃碧慧(Pi-Hui Huang)

《明道學術論壇》 2卷2期 (2006/09) Pp. 55-67

https://doi.org/10.6953/MJ.200609.0055

摘要

水土保持之理論基礎及實務應用多以集水區爲評估單元，近年來隨電腦科技之進步，利用電腦量化集水區坡面泥砂產量資訊，爲坡地災害分析之趨勢。本研究以集水區自動劃分理論爲主軸，結合通用土壤流失公式(USLE)及泥砂遞移率(SDR)之計算，建立集水區坡面泥砂產量推估模式，並以石門、德基、曾文水庫及二仁溪上游集水區爲驗證區域，推估集水區土壤冲蝕量及坡面泥砂產量之空間分佈。集水區坡面泥砂產量之推估結果，石門、德基、曾文水庫及二仁溪上游集水區之年泥砂產量分別爲1928168 tons/yr、1793742 tons/yr、4807205 tons/yr及5074396 tons/yr，年平均冲蝕深度分別爲1.82 mm、2.45 mm、7.10 mm及25.81 mm，以有泥岩分佈之曾文水庫及二仁溪上游集水區較爲嚴重。集水區坡面泥砂產量推估以Nash and Sutcliffe (l970)公式所計算之模式效率(ME)爲81.21%，顯示所建立模式可應用於集水區經營管理之參考。

關鍵字

集水區自動劃分 ； 泥砂產量 ； 泥砂遞移率

並列摘要

Watershed unit has been regarded as an analyzed object for slopeland disaster assessment. With the fast growing progress of computer technologies, there is a trend to automatically estimate watershed-scale sediment yield on slopeland for slopeland disaster prevention. Universal Soil Loss Equation (USLE) and Sediment Delivery Ratio (SDR) coupled with automated watershed delineation theory were applied to estimate watershed sediment yield for Shihmen, Techi, Tsenwen reservoir and Erzen creek watersheds. Annual watershed sediment yields calculated for these watersheds are 1928168 tons/yr. 1793742 tons/yr, 4807205 tons/yr and 5074396 tons/yr, and the corresponding annual erosion depths are 1.82 mm, 2.45 mm, 7.10 mm and 25.81 mm, respectively. Tsenwen reservoir and Erzen creek show higher erosion depth because of moderate mudstone distribution in the watershed. Model efficiency by Nash and Sutcliffe (1970) for sediment yield estimation is 81.21%, the evaluated result shows that the model can be used as the reference of watershed management.

並列關鍵字

Automated Watershed Delineation ； Sediment Yield ； Sediment Delivery Ratio