| 摘要: |
| 【目的】探究不同种植年限压砂地土壤水分吸渗特征及其水力学参数的变化，为恢复压砂地产能、提升区域生态功能及制定合理灌溉制度提供理论支撑。【方法】以宁夏中卫市不同种植年限（2，5，10，20，30和40 a）压砂地为研究对象，利用一维水平土柱吸渗试验，分析不同种植年限压砂地土壤湿润锋深度运移过程和累积入渗量变化规律，采用Philip和Green Ampt模型中吸渗率（S）、土壤水分扩散率（D）等参数分析土壤吸渗特征；采用Brooks-Corey模型计算土壤水分进气吸力（hd）和水吸力（h）等水力学参数，进一步推求土壤水分特征曲线，并反演土壤饱和扩散率（Ds）和非饱和扩散率（D）。【结果】相同吸渗时间下，随着种植年限的增加，湿润锋深度、累积入渗量均呈减小趋势。随种植年限的增加，Philip模型中的S和Green-Ampt模型中的D均呈逐渐减小的趋势。Brooks-Corey模型中，与种植2 a压砂地相比，种植5，10，20，30和40 a压砂地土壤水分的hd分别减小了1.22%，42.81%，46.37%，55.94%和64.97%，Ds分别减小了27.83%，68.54%，85.40%，90.57%和93.15%。在相同土壤含水率下，随着种植年限的增加，h和D均呈减小趋势。【结论】在水分吸渗过程中，随着种植年限的增加，压砂地土壤水分入渗能力及持水能力均明显减低。 |
| 关键词: 压砂地土壤 种植年限 水力学参数 一维水平土柱吸渗试验 水分特征曲线 |
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| 基金项目:国家自然科学基金项目(41867003,41761049)；宁夏自然科学基金项目(2020AAC03049)；宁夏青年科技人才托举工程项目；国家重点研发计划重点项目(2018YFC1802906) |
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| Soil moisture absorption characteristics and hydraulic parameters of gravel-sand mulched fields with different planting years |
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RUAN Xiaohan,BAI Yiru,WANG Youqi,et al
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| Abstract: |
| 【Objective】This study explored soil moisture absorption characteristics and hydraulic parameters of gravel-sand mulched fields with different planting years to provide support for restoring productivity of gravel-sand mulched fields,improving regional ecological functions and formulating a reasonable irrigation system.【Method】The gravel-sand mulched fields with different planting years in Zhongwei,Ningxia were selected and a one-dimensional horizontal absorption experiment was conducted.The depth of wetting front migration process and variation of cumulative infiltration under gravel-sand mulched fields with different planting years of 2，5，10，20，30 and 40 a were studied.The fitting parameters of Philip and Green-Ampt model were used to analyze soil absorption characteristics such as absorption rate (S) and soil moisture diffusion rate (D).The Brooks Corey model was used to calculate hydraulic parameters such as soil water intake suction (hd) and water suction (h).The soil moisture characteristic curve,soil saturated diffusivity (Ds) and unsaturated diffusivity (D) were also deduced.【Result】With the increase of planting years,the depth of wetting front and total cumulative infiltration volume showed a decreasing trend.With the increase of planting years,both S in the Philip model and D in the Green Ampt model showed a decreasing trend.Compared with 2 a,hd in the Brooks Corey model under 5 a,10 a,20 a,30 a and 40 a was reduced by 1.22%,42.81%,46.37%,55.94% and 64.97%,respectively,and Ds was reduced by 27.83%,68.54%,85.40%,90.57% and 93.15%,respectively.Under same soil moisture content,h and D decreased with the increase of planting years.【Conclusion】As the planting years increased,the soil moisture absorption capacity and water holding capacity of gravel-sand mulched fields in the process of water absorption were significantly reduced. |
| Key words: gravel-sand mulched fields soil planting years hydraulic parameters one dimensional horizontal soil column absorption experiment water characteristic curve |
