基于植被恢复边坡稳定性的适宜节水灌溉技术研究

Study on the suitable water-saving irrigation technology based on vegetation restoration and slope stability

在宁夏羊场湾煤矿排矸场边坡野外观测试验站,设2种适宜于当地的植被配置模式,布设不同灌水方式,对坡面土壤水分运移特征及边坡稳定性进行分析研究。结果表明:试验的几种坡面植被灌水形式各有优劣,滴灌效果最佳,微喷次之,渗灌效果不理想;排矸场坡面土壤渗透性较强,水分进入土壤后,呈以顺逆坡方向为长轴、横向方向为短轴的椭圆形向外扩散,顺坡方向入渗速率最高,逆坡方向入渗速率最低,经过一定时间后各方向入渗率趋向稳定;灌溉过程中随着土壤含水量增加,坡面安全系数明显降低,整个坡面土壤含水量为14%时为边坡稳定的安全阈值。

Water is the key factor to ensure plant survival in the process of ecological restoration in the coal base of China northwest deserts.On the premise of meeting the mine production and living water demands,we should take measures such as dirt wastewater treatment and water-saving irrigation to increase income and reduce expenditure,allocate limited water resources rationally,and provide mining area ecological restoration maximum usable water resources.The mining dump has large slope and thin soil layer and it is easy to produce surface runoff.So it is particularly important to study the irrigation technology needed to satisfy vegetation restoration,on the premise of guaranteeing not to produce surface runoff and the slope stability.In this paper,the suitable irrigation method for dump slope,the characteristics of soil moisture migration in slope surface,and slope stability were analyzed by field investigation.Results showed that three slope irrigation technologies had their own advantages and disadvantages.On the whole,the effect of drip irrigation was the best,micro spray irrigation was the second,and infiltrating irrigation was not ideal.The permeability of dump slope was very strong,the infiltration rate of the slope direction was the highest,and in the reverse direction the infiltration rate was the lowest In the process of irrigation,with the increase of soil moisture content,slope safety factor is the decreased obviously,soil moisture content of the whole slope surface is 14% for the slope stability safety threshold.