露天煤矿排土场不同植被类型持水能力评价

采用野外调查和室内综合分析,系统研究了露天煤矿排土场不同植被类型的枯落物特征、土壤物理性质、土壤渗透性能和蓄水能力变化,并采用主成分分析对各样地持水能力进行综合评价。结果表明:不同植被类型枯落物的厚度和蓄积量均差异显著(P0.05),乔木林地、灌木林地和荒草地枯落物厚度依次为1.80,1.23,0.83cm,枯落物蓄积量为6.76,2.96,0.58t/hm~2;乔木林地枯落物的持水能力和拦蓄能力最强,显著大于灌木林地和荒草地(P0.05)。各样地土壤容重依次为荒草地灌木林地乔木林地,乔木林地和灌木林地的土壤入渗能力显著高于荒草地(P0.05),初始入渗率、稳定入渗率和渗透总量分别为1.53~4.08mm/min、0.20~1.51mm/min和28~133mL。乔木林地和灌木林地的实际库容大于荒草地,林地水库贮水效率显著高于荒草地(P0.05)。采用主成分分析法评价露天煤矿排土场不同植被类型的持水能力,15个评价指标可优化为3个主成分,累计贡献率为96.832%,各样地持水能力综合得分为乔木林地灌木林地荒草地。从排土场枯落物层和土壤层的持水能力角度,可选择乔木树种(刺槐)作为主要复垦植被。

Evaluation of Water Retention Capacity of Different Vegetation Types in Dump of Opencast Coal Mine

In the present study,the field investigation and indoor analysis were conducted to study the litter characteristics,soil physical features,soil infiltration characteristics and water retention capacities of different vegetation types in dump of opencast coal mine,and water retention capacities were evaluated by principal component analysis.The results indicated that the thickness and amount of litter were different significantly (P＜0.05) among three vegetation types,and the litter thickness of arbor land,shrub land and weeds land were 1.80,1.23,and 0.83 cm,respectively,and the litter accumulation of three vegetation types were 6.76,2.96,and 0.58 t/hm2,respectively.The water retention capacity and interception capacity of litter in arbor land was the maximum,which was significantly greater than those in shrub land and weeds land (P＜ 0.05).The soil bull density was in the order of weeds land ＞ shrub land ＞ arbor land.The soil infiltration capacity of arbor land and shrub land were significantly greater than that of weeds land,and the infiltration rate,the stable infiltration rate and cumulative infiltration of three vegetation types were 1.53 ～ 4.08 mm/ min,0.20 ～ 1.51 mm/min,28 ～133 mL,respectively.The actual storage capacity of arbor land and shrub land were both greater than that of weeds land,and the water storage efficiency of arbor land and shrub land were significantly higher than that of weeds land (P＜0.05).The water retention capacities of different vegetation types were evaluated by principal component analysis.Fifteen indicators were optimized into 3 principal components,with a cumulative contribution rate of 96.832％.The water retention capacities of different vegetation types were in the order of arbor land ＞ shrub land ＞ weeds land.To improve the water retention capacity of litter and soil of dump,arbor (Robinia pseudoacacia) could be selected as the main reclaimed vegetation.