| 引用本文: | 韩 笑,张 颖,赵君涵,等.含钠盐量变化对土壤水分入渗特性影响的试验研究[J].灌溉排水学报,2020,39(1):61-66. |
| ,et al.含钠盐量变化对土壤水分入渗特性影响的试验研究[J].灌溉排水学报,2020,39(1):61-66. |
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| 摘要: |
| 【目的】研究土壤含钠盐量变化及钠盐含量垂向异性对土壤水分入渗特性的影响，以期为海涂盐渍土水土资源高效利用与保护提供理论依据。【方法】设置土壤含钠盐量垂向均质及垂向异质变化共6个处理，采用恒定水头入渗法进行土壤水分入渗试验。主要从入渗速率、累积入渗量及湿润峰距离3方面对土壤水分入渗特性进行分析讨论与模拟。【结果】对于盐分分布均匀的土壤，入渗初期水分入渗速率与土壤含盐量有显著关系，但对于盐分含盐量垂直分层土，土壤盐分含盐量与水分入渗速率关系较为复杂。在相同入渗时间内，盐分均质土累积入渗量随土壤含盐量增大呈显著降低趋势；对于盐分含盐量分层土壤，盐分含盐量垂向减小土壤累积入渗量大于盐分浓度垂向增加土壤，且土壤剖面垂向盐分含盐量变化对水分累积入渗量影响相比土壤盐分含盐量均匀变化对入渗过程的影响更显著。土壤湿润锋深度随入渗时间延长而增大，且在入渗初期速度较快，随后逐渐缓慢，最后趋于平缓，上层土壤盐分浓度对湿润锋深度影响较大。【结论】结合盐分均匀变化及垂向异质性变化土壤定水头入渗试验，明确了土壤孔隙水分运动与盐分浓度变化的响应规律。土壤垂向理化性质改变对水分入渗过程具有一定影响，同时利用Kostiakov入渗经验公式和简略Philip入渗方程可以较好地拟合该入渗过程。 |
| 关键词: 土壤水分；土壤盐分；水分入渗；累积入渗量 |
| DOI：10.13522/j.cnki.ggps. 20190152 |
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| Spatial distribution of sodic salt in soil affects water infiltration |
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HAN Xiao, ZHANG Ying, ZHAO Junhan, HUANG Rui, WANG Hongde, SHE Dongli
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1. College of Agricultural Engineering, Hohai University, Nanjing 210098, China;2. Jiangning Water Resources Bureau of Jiangsu Province, Nanjing 210098, China
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| Abstract: |
| 【Objective】Soil salinity and sodicity is a ubiquitous abiotic stress affecting agricultural production worldwide. Understanding how sodic salt content modulates water flow in soil can help improve soil management. The objective of this paper is to elucidate the effects of sodic salt content and its spatial distribution on water infiltration.【Method】The experiment compromised six treatments, with the sodic salt distributing either homogenously or heterogeneously in the soil profile. In each treatment, we measured water infiltration using the constant-head method and then compared the infiltration rate, cumulative infiltration and advance of the wetting front between the treatments.【Result】When sodic salt distribution was homogenous, water infiltration rate was related to soil salinity at significant level and the cumulative infiltration decreased with soil salinity, while when the sodic salt was heterogeneous, water movement in the soil was more complicated. Water infiltrated faster when salt content decreased downwards along the soil profile than when salt content decreased upwards. When overall salt content was the same, heterogeneous salt distribution affected cumulative water infiltration more significantly than homogenous salt distribution. The advance of the wetting front in the soil increased with infiltration time, but the infiltration rate decreased asymptotically to a constant as time elapsed. Salt in the top soil affected the advance of the wetting more than salt in the subsoil. 【Conclusion】Our experimental results revealed that water infiltration in saline soil was affected not only by soil salinity but also by how the salt was distributed in the soil profile. Water movement is more intriguing when salt distribution was heterogenous than when it was homogenous. |
| Key words: soil moisture; soil salinity; water infiltration; cumulative infiltration |
