压砂地砂层持水特性研究

发布时间：2018-06-01 10:18

本文选题：压砂地 + 砂层级配　；参考：《土壤通报》2017年02期

【摘要】：通过田间调查和室内土柱模拟方法,对压砂地砂层级配变化规律及砂层持水特性进行了研究,以探讨压砂地保水蓄水性能随着种植年限增加而下降的机理。结果表明:随着种植年限增加,压砂地砂层中粗粒径的砾石含量下降,而小粒径和细粒径的砂粒含量增加;砂层的持水量增大而平均入渗率呈指数下降。在防止蒸发条件下,灌水后1天10 cm砂层含水量最大值可以达到6.5%,蓄水量最大值和最小值分别为12.5 mm和6.0 mm,分别占灌水量的31.5%和15.2%。影响砂层含水量的主要是粒径为0.315~0.63 mm的砂砾。可见,随着种植年限增加,砂层中砾石含量降低而粗、细砂粒含量增加,进而降低了降雨的入渗速率和提高了砂层的蓄水截留能力,这是导致压砂地土壤保水蓄水性能降低的主要原因。
[Abstract]:By means of field investigation and soil column simulation, the variation law of sand gradation and the water holding capacity of sand layer were studied in order to explore the mechanism of decreasing water storage performance of sand compaction soil with the increase of planting years. The results show that with the increase of planting time, the gravel content of coarse diameter in sand bed decreases, while the content of small diameter and fine diameter of sand increases, and the water holding capacity of sand layer increases, but the average infiltration rate decreases exponentially. Under the condition of preventing evaporation, the maximum water content of 10 cm sand layer can reach 6.5mm on the first day after irrigation, and the maximum and minimum water storage value are 12.5 mm and 6.0 mm respectively, accounting for 31.5% and 15.2mm of the irrigation amount respectively. The sand gravel with the diameter of 0.315 ~ 0.63 mm is the main factor affecting the water content of sand bed. It can be seen that with the increase of planting years, the gravel content in sand layer decreases while the coarse sand content increases, and the fine sand content increases, which reduces the infiltration rate of rainfall and improves the water retention capacity of sand bed. This is the main reason for the decrease of soil water retention and storage performance.
【作者单位】：宁夏大学土木与水利工程学院;旱区现代农业水资源高效利用教育部工程研究中心;宁夏节水灌溉与水资源调控工程技术研究中心;宁夏大学农学院;
【基金】：宁夏自然科学基金项目(NZ1037) 国家自然科学基金项目(51309135,31460546)资助
【分类号】：S152.7

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