工程堆积体入渗特性及持水能力对降雨条件的响应

Response of Infiltration Property and Water-holding Capacity of Engineering Accumulation to Rainfall

为探讨降雨对工程堆积体入渗特性及持水能力的影响,采用室内土壤基本物理性质分析及野外双环入渗方法,对不同降雨条件下工程堆积体入渗特性及持水能力的变化及影响因素进行研究。结果表明:工程堆积体土壤基本物理性质在不同降雨条件和坡位有较大差异,不同降雨条件下工程堆积体坡下的土壤容重大小表现为干旱(Ⅰ)>小雨(Ⅱ)>中雨(Ⅲ)>大雨(Ⅳ);不同坡位工程堆积体的总孔隙度、毛管孔隙度、非毛管孔隙度大小表现为坡下>坡中>坡上。不同降雨条件下,初始入渗速率大小表现为干旱(Ⅰ)>小雨(Ⅱ)>大雨(Ⅳ)>中雨(Ⅲ),其大小依次为8.91,5.52,3.96,3.25mm/min;稳定入渗率大小表现为干旱(Ⅰ)>中雨(Ⅲ)>小雨(Ⅱ)>大雨(Ⅳ),其大小依次为4.40,1.45,1.32,0.53mm/min。不同降雨条件下工程堆积体坡下的最大有效库容大小表现为大雨(Ⅳ)>小雨(Ⅱ)>干旱(Ⅰ)>中雨(Ⅲ),其大小依次为469.03,402.48,378.11,321.88t/hm2,中雨(Ⅲ)条件下工程堆积体在各坡位的田间持水量最大。工程堆积体的持水能力与总孔隙度、毛管孔隙度、入渗性能呈显著正相关关系,而与容重呈显著负相关关系。研究结果可为工程堆积体边坡水土流失防治提供重要科学依据。

In order to explore the influence of rainfall on infiltration characteristics and water holding capacity of engineering accumulation,the laboratory basic soil physical properties analysis and field double ring infiltration methods were used to study the changes of infiltration characteristics and water holding capacity of engineering accumulation in different rainfall conditions and its influencing factors.The results showed that soil bulk density and soil porosity of engineering accumulation had significant differences in different rainfall conditions and slope positions.In different rainfall conditions,the soil bulk density of engineering accumulation of lower of slope from high to low were：Drought（Ⅰ）light rain（Ⅱ）moderate rain（Ⅲ）heavy rain（Ⅳ）.Total porosity,capillary porosity,non-capillary porosity in different slope positions from high to low were：Lowermiddletop.In different rainfall conditions,the initial infiltration rate from high to low were：Drought（Ⅰ）light rain（Ⅱ）heavy rain（Ⅳ）moderate rain（Ⅲ）,its size in order to 8.91,5.52,3.96,3.25mm/min.The stable infiltration rate from high to low were：Drought（Ⅰ）moderate rain（Ⅲ）light rain（Ⅱ）heavy rain（Ⅳ）,its size in order to 4.40,1.45,1.32,0.53mm/min.In different rainfall conditions,the maximal effective capacity of engineering accumulation of lower of slope from high to low were：Heavy rain（Ⅳ）light rain（Ⅱ）drought（Ⅰ）moderate rain（Ⅲ）,its size in order to 469.03,402.48,378.11,321.88t/hm2.In different slope positions of engineering accumulation,the field capacity of moderate rain condition was largest.The water-holding capacity of engineering accumulation had a significant positive correlation with total porosity,capillary porosity,non-capillary porosity and infiltration characteristics,while it had a significant negative correlation with soil bulk density.The results could provide impor-tant scientific evidence basis for the prevention and control of soil and water loss of engineering accumulation.