矿区排土场土壤水分物理特性及其改良研究

发布时间：2019-05-15 10:45

【摘要】：露天煤矿的开采与开发,会破坏地形地貌,毁坏植被,减少生物多样性,造成水土流失等。开采露天煤矿所形成的排土场,是由大量煤矿开采剥离物以及弃土弃渣堆砌而成的一种巨型人工地貌。露天煤矿开采改变地形地貌,破坏地表径流,而该区域年降雨量少且降雨集中,水成为限制排土场上的植被恢复的主要因素。通过对矿区排土场不同植被恢复模式下土壤水分特性的研究,可以探究不同植被模式下土壤的恢复状况,并结合当地实际状况,以选择出适合当地的植被恢复模式,通过对添加砒砂岩、粉煤灰对排土场土壤水分特性的影响进行研究,比较不同处理土壤的水分物理性质,探究最适合的添加比例,为矿区植被恢复与土地复垦提供支持。本文以黑岱沟露天煤矿东排土场为研究对象,选取排土场平台上草地(苜蓿)、灌木林地(沙棘林地)、乔灌混交林地(杨树×沙棘)、乔木林地(杨树林地)四种植被恢复模式,并以排土场外选择的自然恢复下的草地(荒草地)、灌木林地(沙棘林的)为对比,研究植被恢复对排土场土壤水分物理特性的影响。将砒砂岩、粉煤灰与排土场按照一定比例充分混合,研究砒砂岩、粉煤灰对排土场土壤水分物理性质的改良作用。取得以下主要结果:(1)黑岱沟东排土场土壤物理性质较差,其中容重平均为1.51g/cm3,总孔隙度平均为42.39%,毛管孔隙度平均为39.31%,非毛管孔隙为3.39%,远低于耕层50~56%,非毛管孔隙状况8~10%的要求,饱和含水量平均为28.51%,田间持水量平均为24.18%。(2)不同植被恢复模式下,土壤的物理性质有所差异。乔木地土壤容重平均为1.58g/cm3,最接近新建排土场,乔灌混交林地最小,为1.47g/cm3;乔灌混交林地的非毛管孔隙度最高为4.35%,乔木地最低,为2.74%,但都低于新建排土场;乔灌林地的饱和含水量最高为29.56%,最低为乔木地的26.13%。(3)Gardner模型对不同植被恢复模式下土壤水分特征曲线和砒砂岩、粉煤灰改良后土壤的水分特征曲线拟合度较高,R2最低为沙棘地(0.9311),最高为L1F1S1(0.9929)。(4)不同植被恢复模式下排土场土壤持水性为排土场草地自然草地排土场灌木地排土场乔灌混交林地自然灌木地排土场乔木地;土壤供水性的顺序为自然草地自然沙棘排土场乔灌混交排土场草地排土场灌木地排土场乔木地。从改善土壤水分特性看,排土场上的植被恢复模式,应优先选择草地。(5)砒砂岩、粉煤灰都可增加排土场土壤的持水性,且添加比例越高,土壤持水性越强。仅加入砒砂岩后会导致土壤供水能力的下降。但给土壤加入同等比例的砒砂岩和粉煤灰混合物,即三者比例为1:1:1时,土壤供水性和持水性最强。
[Abstract]:The mining and development of opencast coal mine will destroy topography and landform, destroy vegetation, reduce biodiversity, cause soil and water loss and so on. The dump formed by mining opencast coal mine is a kind of huge artificial landform, which is made up of a large number of coal mine stripping materials and abandoned soil and slag. Open pit coal mining changes the topography and landform and destroys the surface runoff, but the annual rainfall in this area is less and the rainfall is concentrated. Water has become the main factor restricting the vegetation restoration on the dump. Through the study of soil moisture characteristics under different vegetation restoration models in mining area dump, the soil restoration status under different vegetation models can be explored, and combined with the local actual situation, the suitable vegetation restoration model can be selected. Through the study of the effect of adding soft rock and fly ash on the soil moisture characteristics of the dump, the physical properties of soil moisture in different treatments were compared, and the most suitable adding ratio was explored, which provided support for vegetation restoration and land reclamation in mining area. In this paper, the east dump of Heidaigou opencast coal mine is taken as the research object, and the grassland (Medicago sativa), shrubs (seabuckthorn forest) and Joe irrigation mixed forest (poplar 脳 seabuckthorn) on the platform of the dump are selected. There are four vegetation restoration models in Arbor forest land (poplar forest land), and the grassland (wasteland) and shrubby forest land (seabuckthorn forest) selected outside the dump are compared. The effect of vegetation restoration on the physical properties of soil moisture in dump was studied. The physical properties of soil moisture in soft rock and fly ash were studied by mixing soft rock, fly ash and dump in a certain proportion. The main results are as follows: (1) the soil physical properties of Heidaigou East dump are poor, in which the average bulk density is 1.51 g 鈮，

本文编号：2477442