本文選題：降雨和匯流　切入點(diǎn)：地表?xiàng)l件　出處：《中國科學(xué)院研究生院(教育部水土保持與生態(tài)環(huán)境研究中心)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：研究黑土區(qū)坡面侵蝕影響因素將為黑土區(qū)侵蝕防治和黑土資源保護(hù)提供重要的科學(xué)依據(jù)。本文以吉林省榆樹市典型黑土區(qū)坡面土壤為研究對象,以降雨和匯流兩種侵蝕動力為切入點(diǎn),采用模擬降雨和上方匯流試驗(yàn)相結(jié)合的研究方法,闡明侵蝕動力條件(降雨能量、降雨強(qiáng)度和上方匯流)和地表?xiàng)l件(坡度、坡長、土壤結(jié)皮和翻耕深度)對黑土區(qū)坡面侵蝕過程的影響,揭示黑土區(qū)坡面侵蝕的水動力學(xué)機(jī)理。主要研究結(jié)論如下:(1)分析了降雨能量、降雨強(qiáng)度和匯流強(qiáng)度對黑土區(qū)坡面土壤侵蝕的影響。與消除降雨能量的試驗(yàn)條件相比,有降雨能量試驗(yàn)條件下的坡面徑流量僅增加了12.8%~39.7%,而坡面侵蝕量則增加了1.7~1.9倍。降雨強(qiáng)度由50 mm h-1增加到100mm h-1時,坡面徑流量和侵蝕量分別增加了1.4~12.4和4.2~6.1倍。匯流強(qiáng)度對坡面侵蝕過程的影響受坡面侵蝕方式的影響。當(dāng)坡面以片蝕為主時,匯流強(qiáng)度由50 L min-1增加到150 L min-1,坡面侵蝕量無顯著性變化,而當(dāng)匯流強(qiáng)度由150 L min-1增加到300 L min-1,坡面侵蝕量呈明顯增加趨勢。而當(dāng)坡面以細(xì)溝侵蝕為主時,坡面侵蝕量隨匯流強(qiáng)度的增加而呈明顯的增加趨勢;與匯流強(qiáng)度50 L min-1相比,匯流強(qiáng)由100 L min-1增加到300 L min-1時,坡面侵蝕量增加了6.2~61.7倍。(2)剖析了降雨和匯流兩種侵蝕動力條件下地形因子和地表?xiàng)l件對坡面侵蝕特征的影響。降雨侵蝕動力條件下,坡長由5 m增加到10 m時,在相同降雨強(qiáng)度和坡度試驗(yàn)條件下,坡面徑流量和侵蝕量分別增加了0.1~3.1和2.1~2.9倍;坡度由5°增加到10°時,在相同降雨強(qiáng)度和坡長試驗(yàn)條件下,坡面侵蝕量增加了0.4~0.9倍。匯流侵蝕動力條件下,匯流強(qiáng)度由50 L min-1增加到300 L min-1時,坡度由5°增加到10°引起坡面侵蝕量增加了2.6~201.0倍。地表結(jié)皮對坡面侵蝕的影響受降雨強(qiáng)度、坡度和坡長的綜合影響。翻耕深度由5 cm增加到20 cm時,坡面侵蝕量變化受降雨強(qiáng)度和坡度的綜合影響;而匯流侵蝕動力條件下坡面侵蝕量變化隨翻耕深度的變化受坡面侵蝕方式的影響。(3)分析了降雨和匯流兩種侵蝕動力條件下影響黑土區(qū)坡面侵蝕的主要因素。降雨侵蝕動力條件下影響坡面侵蝕的主要因素是坡長;并建立了坡面侵蝕量與坡長、降雨強(qiáng)度—坡長交互作用的經(jīng)驗(yàn)關(guān)系式。匯流侵蝕動力條件下影響坡面侵蝕的主要因素是匯流強(qiáng)度—坡度交互作用;建立了坡面侵蝕量與匯流強(qiáng)度—坡度交互作用的經(jīng)驗(yàn)關(guān)系式;匯流侵蝕動力條件下坡面侵蝕量與徑流量相關(guān)關(guān)系受侵蝕方式的影響較為明顯。(4)探究了降雨侵蝕動力條件下的坡面侵蝕的水動力學(xué)機(jī)理。隨降雨強(qiáng)度、坡度和坡長的增加,徑流流速、雷諾數(shù)和弗汝德數(shù)均呈增加趨勢,而Darcy-Weisbach阻力系數(shù)則呈減少趨勢。土壤結(jié)皮的存在使得坡面Darcy-Weisbach阻力系數(shù)降低了25.6%~40.3%。翻耕深度由5 cm增加到20 cm時,坡面平均流速降低了36.8%~40.2%,Darcy-Weisbach阻力系數(shù)則分別增加了1.5~1.8倍。降雨侵蝕動力條件下坡面侵蝕量與徑流剪切力、徑流功率以及單位徑流功率間無顯著的線性關(guān)系;而坡面侵蝕量與徑流流速和弗汝德數(shù)呈極顯著正相關(guān)關(guān)系,與Darcy-Weisbach阻力系數(shù)呈顯著負(fù)相關(guān)關(guān)系。(5)探討了上方匯流侵蝕動力條件下的坡面侵蝕水動力學(xué)機(jī)理。隨匯流強(qiáng)度和坡度的增大,徑流平均流速、雷諾數(shù)和弗汝德數(shù)均有所增加;Darcy-Weisbach阻力系數(shù)則逐漸降低。翻耕深度對坡面水力學(xué)參數(shù)的影響受坡度和匯流強(qiáng)度的綜合影響。分別建立了坡面侵蝕侵蝕量與徑流剪切力、徑流功率和單位徑流功率的關(guān)系式。徑流流速和單位水流功率是表征坡面侵蝕的最佳水力學(xué)和水動力學(xué)參數(shù)。
[Abstract]:Will provide important scientific basis for the prevention of erosion in black soil region and black soil resources protection slope erosion influence factors of black soil area. Taking soil slope in typical black soil in Yushu city of Jilin Province as the research object, with rainfall and two kinds of runoff erosion power as the starting point, the simulation methods of rainfall and runoff over the test combination. To clarify the erosion dynamic conditions (rainfall intensity and rainfall runoff energy, above) and surface conditions (slope, slope length, soil crust and ploughing depth) influence on the process of black soil erosion of slope, reveal the hydrodynamic mechanism of slope erosion in black soil region. The main conclusions are as follows: (1) analyzed rainfall energy. The intensity of rainfall intensity on the influence and confluence in black soil zone of slope soil erosion. Compared with the experimental conditions to eliminate rainfall energy, rainfall energy test under the condition of runoff increased by only 12.8%~39.7%, and slope The erosion amount is increased by 1.7~1.9 times. The rainfall intensity increased from 50 mm H-1 to 100mm H-1, slope runoff and soil erosion were increased 1.4~12.4 and 4.2~6.1 times. Effect of intensity on the slope erosion process of runoff is affected by soil erosion patterns. When the slope in sheet erosion, runoff intensity increased by 50 L min-1 L to 150 min-1, the slope erosion and no significant changes, and when the concentration increased from 150 L to 300 L min-1 min-1 increased, the slope erosion was significantly increased. When the slope in rill erosion is increased with slope erosion intensity and concentration were increased; compared with the bus the intensity of 50 L min-1, the confluence of strong increases from 100 L to 300 min-1 L min-1, the rate of soil erosion increased by 6.2~61.7 times. (2) analyzed the influence of the rainfall and the confluence of two kinds of erosion under dynamic conditions topography and surface conditions on the erosion characteristics of the slope. Under the condition of rainfall erosion force, slope length increased from 5 m to 10 m, in the same rainfall intensity and slope conditions, slope runoff and soil erosion were increased 0.1~3.1 and 2.1~2.9 times; the slope increased from 5 degrees to 10 degrees, in the same rainfall intensity and slope length under the experimental conditions, the slope erosion the amount of 0.4~0.9 times. The confluence of erosion under dynamic conditions, convergence intensity increased from 50 L to 300 min-1 L min-1, the slope from 5 degrees to 10 degrees increase caused by slope erosion increased by 2.6~201.0 times. Surface crust by the impact of rainfall intensity on soil erosion on the slope, slope and slope length of the comprehensive effect of tillage. The depth increased from 5 cm to 20 cm, the slope erosion changes affected by the rainfall intensity and slope runoff erosion; and dynamic conditions of slope surface erosion varies with the depth of ploughing is affected by soil erosion patterns. (3) analysis of the rainfall and the confluence of two kinds of erosion Main factors affecting the soil area of slope erosion under dynamic conditions. The rainfall erosion under dynamic conditions are main factors affecting soil erosion on the slope and slope length; established slope erosion and slope length, empirical formula of rainfall intensity, slope length interaction. The confluence of erosion dynamical conditions, main factors affecting soil erosion intensity is confluence slope interaction; established empirical formula of slope erosion and runoff intensity slope interaction; runoff erosion power slope erosion and runoff relationship affected by erosion is obvious. (4) to explore the dynamic mechanism of water erosion under dynamic conditions of slope erosion. With the rainfall intensity. The slope and the slope length increases, the runoff velocity, Reynolds number and Froude number increased, while the Darcy-Weisbach resistance coefficient decreased. Soil crusts are the slope Darcy-Weisbach resistance coefficient decreased 25.6%~40.3%. ploughing depth increased from 5 cm to 20 cm, the average flow rate decrease 36.8%~40.2%, Darcy-Weisbach resistance coefficient was increased by 1.5~1.8 times. The rainfall erosion dynamic conditions of slope surface erosion and runoff shear stress, no significant linear relationship between runoff and runoff power unit power and slope; soil erosion and runoff velocity and Vladimir positive correlation was found between the Froude number, there was a significant negative correlation between resistance coefficient and Darcy-Weisbach. (5) discussed the dynamic mechanism of slope water erosion above the confluence of erosion under dynamic conditions. With the increase of runoff intensity and slope runoff, average flow velocity, Reynolds number and Froude the number of Darcy-Weisbach increased; resistance coefficient decreased. Effect of tillage depth on the slope hydraulics parameters affected by the slope and discharge intensity were established. The relationship between erosion and erosion amount and runoff shear force, runoff power and unit runoff power is also discussed. Runoff velocity and unit flow power are the best hydraulic and hydrodynamic parameters to characterize slope erosion.

【學(xué)位授予單位】：中國科學(xué)院研究生院(教育部水土保持與生態(tài)環(huán)境研究中心)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：S157.1
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本文編號：1558778