黄土高原水蚀风蚀交错区不同下垫面土壤水蚀特征实验研究

Soil Water Erosion Processes on Sloping Land with Different Material in the Wind-Water Interaction Zone in the Loess Plateau

以位于黄土高原水蚀风蚀交错区的神东矿区为研究基地,以黄土、沙黄土、风沙坡、基岩风化坡地、人为弃矿渣为物质基础,采用野外人工模拟降雨的方法,重点分析不同组成物质和同一物质不同固结程度斜坡地的土壤水蚀特征。对系列实验数据,应用SPSS和DPS数据处理系统进行分析。结果表明:①在条件相近的情况下,场降雨侵蚀模数的排序为:黄土>沙黄土>沙坡>弃矿渣>风化壳;②在相同的雨强和坡度条件下,黄土坡面产流快,易形成细沟、浅沟,使坡地变得起伏不平;沙黄土坡面则产流慢,形成沟谷的时间较迟,但演化快。③多石块的粗骨性风化壳侵蚀量随降雨强度的增加而增加,但产沙过程却以产流初期最大,之后趋于减少并稳定;④同一物质不同堆积年限的坡地,在没有人为破坏的情况下,随着堆积年限的增加而固结程度提高,侵蚀模数由16 379 t/(km2.a)下降到1 227 t/(km2.a)。⑤弃矿渣坡地的侵蚀容易出现滑塌和滑坡,产沙过程波动明显,有短暂的高含沙量的泥石流过程。

Shenfu-Dongsheng mine region,which is in the central of wind-water interaction zone of the Loess Plateau,was taken as researching region. Loess ,sand loess ,sand,regolith and accumulation of waste mine residue were taken as researching material. By the tests of artificial simulation of rainfall on sloping land with different material and on the sloping land with same material （sand） and different accumulation years ,and the statistic analysis of test data with SPSS and DPS,some new and peculiar water erosion processes were observed and described. The conclusions were listed as following. ①In the similar conditions ,the order of erosion modulus per set artificial simulated rainfall is loess〉sand loess〉sand slope〉accumulation of waste mine residue〉regolith）. ②In the same the intensity of rainfall and slope,it is easier to come into being the runoff and gully on the sloping land with loess than sand loess ,but the gully evolution is speedier on the sloping land with sand loess than loess. ③On regolith slope land with much rock block,erosion modulus increase as intensity of rainfall increase. The runoff silt content is the highest at initial stages of runoff forming and goes gradually lower and more stable. ④On the sloping land with same material（sand） and different accumulation years ,the soil erodibility increases as accumulation years increase and erosion modulus decreases from 16 379 t/（km^2 ·a） to 1 227 t/（km^2 · a）,under the conditions of no human activity. ⑤On the accumulation slope of waste mine residue, slide and landslide are main erosion ways, the processes of runoff silt content is undulate ,there is debris processes with short time and high silt content.