本文選題：人工模擬降雨　切入點：黑土坡面　出處：《東北師范大學》2015年碩士論文

【摘要】：黑土是一種性狀好、肥力高,非常適合植物生長的土壤[1]。但是近幾十年來,由于自然因素和人們不合理的生產(chǎn)經(jīng)營活動,黑土侵蝕退化嚴重,主要是以水蝕和風蝕為主,造成土壤肥力下降。而黑土區(qū)作為我國重要的商品糧基地,土壤肥力下降,對該地區(qū)的土地生產(chǎn)力、糧食生產(chǎn)和區(qū)域社會經(jīng)濟發(fā)展都造成嚴重的影響。因此,本文以中國東北地區(qū)的黑土坡耕地為研究對象,利用人工模擬降雨機進行室內(nèi)模擬降雨試驗,在雨強為60 mm/h的條件下,利用變坡土槽研究坡面坡度分別為1°、3°、5°、7°和9°時,產(chǎn)流時間、流速、平均入滲率、徑流量、累計徑流量等產(chǎn)流特征以及侵蝕泥沙量、累計泥沙量、徑流含沙率等產(chǎn)沙特征,探討黑土坡面產(chǎn)流產(chǎn)沙規(guī)律。研究得出以下結(jié)論:(1)在降雨強度一定的情況下,隨著黑土坡面坡度增加,干、濕運行下,產(chǎn)流時間變化趨勢不同;干運行下,坡度越大,產(chǎn)流時間越短;濕運行下,隨著坡度的增大產(chǎn)流時間變化趨勢不明顯。(2)干、濕兩種運行狀態(tài)下,均隨著黑土坡面坡度增加,坡面平均入滲率減小;同一個坡度下,干、濕兩種運行狀態(tài)下,坡面平均入滲率變化不大,且坡面平均入滲率隨著降雨歷時的增加而減少。(3)干、濕兩種運行狀態(tài)下,隨著黑土坡面坡度的增加,徑流流速加快,而在坡度一定的情況下,隨著降雨時間的增加,干、濕運行狀態(tài)下流速均呈增快趨勢,但干運行狀態(tài)下流速比濕運行下流速增加得快。發(fā)現(xiàn)干運行狀態(tài)下3°、5°、7°時流速與降雨歷時呈現(xiàn)冪函數(shù)關(guān)系,9°時流速與降雨歷時呈線性關(guān)系。濕運行狀態(tài)下1°、7°、9°下,流速與降雨歷時呈指數(shù)關(guān)系,3°、5°下徑流流速與降雨歷時呈指函數(shù)關(guān)系。(4)在降雨歷時一定的情況下,黑土坡面坡度越大,累計產(chǎn)流量越大。坡度一定時,隨著降雨時間的增加,累計產(chǎn)流量在增加。干運行下,累計產(chǎn)流量與降雨歷時呈現(xiàn)線性關(guān)系;濕運行下,累計產(chǎn)流量與降雨歷時呈冪函數(shù)關(guān)系。(5)在降雨強度一定的情況下,干、濕兩種運行狀態(tài)下,坡度越大,侵蝕含沙量越大;干運行狀態(tài)下,當坡度為3°、5°時,隨著降雨歷時的增加而增加,7°、9°時先增加,達到一定值后,基本保持恒定;濕運行狀態(tài)下時,坡度為1°、3°、5°、7°時,侵蝕含沙量先增加,后保持恒定,9°時一直在增加。(6)在降雨強度一定的情況下,干、濕兩種運行狀態(tài)下,坡度越大,累計含沙量越大。而當坡度一定時,累計含沙量在兩種狀態(tài)下均隨著降雨時間的增加而增加。(7)在降雨強度一定的情況下,干、濕兩種運行狀態(tài)下,坡度越大,侵蝕含沙率越大,且侵蝕含沙率與降雨時間符合二次項關(guān)系。(8)黑土坡面隨著徑流所攜帶的泥沙的顆粒以小粒徑的粘粒和粉粒為主。并且土壤機械組成與坡面產(chǎn)沙關(guān)系明顯。砂礫與侵蝕泥沙的關(guān)系最顯著,粒徑2 mm的石礫與侵蝕泥沙量、累計含沙量、含沙率均存在不同程度的正相關(guān);坡面侵蝕泥沙量、累計泥沙量、徑流含沙率增加的過程中,粒徑在0.05~0.002 mm之間的粉粒和0.002 mm的粘粒所占的比重在減少。(9)人工模擬降雨下,黑土坡面產(chǎn)沙特征與產(chǎn)流特征關(guān)系顯著,尤其是流速與累計含沙量。分析發(fā)現(xiàn),流速與累計含沙量在5個坡度即1°、3°、5°、7°、9°下,均存在極強的相關(guān)性。流速越大時,累計含沙量越大。
[Abstract]:Black soil is a kind of good character, very suitable for soil fertility, [1]. plant growth but in recent decades, due to natural factors and people's unreasonable production activities, soil erosion serious degradation is mainly by wind and water erosion, resulting in the decrease of soil fertility. The black soil zone as an important commodity grain base in China and the decline in soil fertility, the area of land productivity and seriously affect grain production and regional social and economic development. Therefore, based on the slope farmland in the black soil in Northeast China Chinese as the research object, simulated rainfall experiments were carried out using artificial rainfall simulation machine, rainfall intensity of 60 mm/h under the condition of using the variable slope study on the soil trough slope gradient was 1 degrees, 3 degrees, 5 degrees, 7 degrees and 9 degrees, the time of runoff, flow rate, average infiltration rate, cumulative runoff, runoff and runoff characteristics and erosion sediment amount, the cumulative amount of sediment runoff. The rate of sediment and sediment, on black soil slope runoff and sediment production. The research draws the following conclusions: (1) in the case of certain rainfall intensity, slope gradient increased with soil, dry, wet operation, runoff time varied; dry run, the greater the slope runoff, the shorter the time; wet operation, with the increase of slope runoff change trend is not obvious. (2) dry, wet two kinds of operating conditions, with the increase of black soil slope gradient, slope average infiltration rate decreases; with a slope under dry, wet two kinds of operating conditions, the slope average infiltration rate changes is small, and the slope average infiltration rate decreased with the increase of rainfall duration. (3) dry, wet two kinds of operating conditions, with the increase of soil slope, runoff flow speed, and in the slope under certain conditions, with the increase of rainfall time, dry, wet condition showed a faster speed down but the trend. 騫茶繍琛岀姸鎬佷笅嫻侀，

本文編號：1697342