不同复垦方式排土场砾石对饱和导水率和贮水能力的影响

发布时间：2018-05-25 03:16

本文选题：砾石 + 饱和导水率　；参考：《土壤学报》2017年06期

【摘要】：露天煤矿排土场是由矿井下采出的煤矸石,露天矿剥离的表土、岩石及覆土共同组成的松散土石混合堆积体,其内部含有的砾石对土体导水性能和贮水能力有重要影响,以往关于砾石对土壤水分的影响多集中于自然土壤,缺乏对排土场、弃渣场等土石混合工程堆积体的水文-侵蚀过程研究。以海州露天煤矿排土场为研究对象,基于野外调查采样和室内定水头入渗试验,研究了排土场不同复垦方式下土体砾石分布特征及其对饱和导水率和贮水能力的影响,以期为提高矿区水土资源利用效率提供理论依据。结果表明,不同复垦方式下排土场砾石总量随土层深度呈现增加的趋势,并且土体剖面砾石总量的平均值表现为农用地最小,这可能是由频繁耕作导致,不同土层之间砾石总量无显著差异;排土场土体不同粒径砾石相对含量平均值的大小顺序为(2~10 mm)(20 mm)(10~20 mm),表现为大粒径砾石在各种因素的综合作用下正逐渐变为细粒径;排土场土体饱和导水率均表现为灌木林地最高,农用地和荒草地较低;饱和导水率与各粒径砾石含量之间呈极显著线性正相关,且随着砾石粒径的增大其相关性越强;排土场土体贮水能力各指标均以灌木林地和荒草地最强,乔木林地和农用地最差,并且饱和贮水量与各粒径的砾石含量之间均存在显著或极显著的相关关系,最大滞留贮水量与各粒径的砾石含量之间均呈现显著的幂函数相关关系,最大吸持贮水量与粒径2~10 mm砾石含量之间存在显著抛物线相关关系;对于20 mm的粒径而言,影响土壤贮水能力的砾石含量阈值为14%。
[Abstract]:Opencast coal mine dump is a kind of loose soil and rock mixed accumulation composed of coal gangue, peeled surface soil, rock and overburden. The gravel contained in the dump has important influence on the water conductivity and water storage capacity of soil. In the past, the influence of gravel on soil moisture was mainly concentrated in natural soil, and the hydrological erosion process of soil and rock mixed engineering such as dump site, dump site and so on was not studied. Taking the dump of Haizhou opencast coal mine as the research object, based on the field investigation and indoor constant head infiltration test, the distribution characteristics of soil gravel and its influence on saturated water conductivity and water storage capacity under different reclamation methods were studied. The aim is to provide theoretical basis for improving the utilization efficiency of water and soil resources in mining area. The results showed that the aggregate of gravel increased with the depth of soil layer under different reclamation methods, and the average value of total aggregate of gravel in soil profile was the smallest, which may be caused by frequent tillage. There is no significant difference in the total gravel content among different soil layers, and the order of the average relative content of gravel of different particle size in the dump soil is in the order of 10 mm)(20 mm)(10~20 / mm, which shows that the large size gravel is gradually becoming fine particle size under the combined action of various factors. The saturated water conductivity of soil in dump is the highest in shrub land, lower in agricultural land and wasteland, and there is a very significant linear positive correlation between saturated water conductivity and gravel content, and the stronger the correlation is with the increase of gravel particle size. The water storage capacity of soil in dump was the strongest in shrub land and wasteland, and the worst in Arbor and agricultural land, and there was a significant or extremely significant correlation between saturated water storage and gravel content of different particle sizes. There was a significant power function correlation between the maximum retained water storage and the gravel content of each particle size, and a significant parabola correlation between the maximum retention water content and the gravel content of 210mm diameter, and for the particle size of 20mm, there was a significant correlation between the maximum retention water content and the gravel content of each particle size. The threshold value of gravel content affecting soil water storage capacity is 14%.
【作者单位】：辽宁工程技术大学环境科学与工程学院;辽宁工程技术大学水土保持生态修复研究院;四川省水利科学研究院;
【基金】：国家自然科学基金项目(51474119)资助~~
【分类号】：S152.7

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