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利用黄土高原2种典型的土壤类型(黄土和塿土),在2个降雨强度(45.5,95.5mm/h)和2个坡度(8.7%,25.9%)条件下进行了人工模拟降雨试验,研究了3种水质(去离子水、自来水、盐水)对坡面产流、产沙过程的影响。结果表明,2种土壤类型的产流过程差异显著,黄土条件下去离子水最先产流,但产流速率小于自来水与盐水;而塿土条件下去离子水的产流速率始终最大,自来水与盐水由于离子数量相当,产流速率差异较小。水质主要通过地表结皮的形成与发育影响径流,以总降水量45.5mm为例,径流深随供水电导率的增大而减少,与去离子水相比,黄土条件下自来水和盐水的径流分别减少了5.7 mm和1.5mm,而塿土条件下分别减少了7.2mm和9.8mm。受产流过程的影响,不同供水水质条件下产沙过程不一,产沙速率与产流速率变化同步。2种土质条件下产沙量均是去离子水最大,与去离子水相比,自来水和盐水分别减少了45.9%,35.8%(黄土)和65.6%,68.3%(塿土),结果显示模拟降雨水质会显著影响坡面产流产沙过程,为保证试验数据的准确性和可对比性,建议在进行人工降雨相关试验时均采用去离子水。
Simulated rainfall experiments were conducted under two rainfall intensities (45.5, 95.5 mm / h) and two slopes (8.7%, 25.9%) using two typical soil types (loess and loam) on the Loess Plateau. The effects of three kinds of water quality (deionized water, tap water, salt water) on the runoff and sediment yield on the slope were studied. The results showed that there were significant differences in runoff process between the two soil types. The deionized water was the first to produce runoff in loess condition, but the runoff rate was less than that of tap water and brine. However, the runoff rate of deionized water was the highest, Due to the same amount of ions, the difference in the flow rate is small. The water quality is mainly influenced by the formation and development of surface crusts and runoff. Taking the total precipitation at 45.5mm as an example, the runoff depth decreases with the increase of water supply conductivity. Compared with deionized water, the runoff of tap water and brine in loess Decreased by 5.7 mm and 1.5 mm, respectively, while the soil conditions were reduced by 7.2 mm and 9.8 mm, respectively. Affected by the process of runoff production, the process of sediment production is different under different water quality conditions, and the rate of runoff and runoff rate are synchronized. The sediment yield of the two soil types was the largest in deionized water. Compared with deionized water, tap water and saline water decreased by 45.9%, 35.8% (loess) and 65.6%, 68.3% (loamy soil), respectively. The results showed that the simulated Rainfall water quality will significantly affect the process of runoff and sediment production on the slope. To ensure the accuracy and comparability of test data, it is suggested that deionized water should be used during the test of artificial rainfall.