Abstract:

Wind-eroded deserts and oasis farmlands are typical manifestations of Xinjiang’s dryland surface landscape， and water scarcity has become an important limiting factor for local agricultural development. In order to reveal the water movement patterns under different sand blending modes of soils， the water movement characteristics of 3 soil sand blending modes， namely， surface sand cover （TF）， deep buried sand （TG） and shallow mixed sand （TH）， were investigated based on ponding infiltration tests and combined with HYDRUS-1D software， using a homogeneous loam as control （CK）. The results showed that the measured and simulated values of cumulative infiltration were in good agreement， with coefficients of determination （ R²） ranging from 0.998 1 to 0.999 3 and root mean square errors （RMSE） ranging from 0.135 3 to 0.220 4. The HYDRUS-1D numerical model had good applicability and reliability for the inversion of soil hydraulic parameters under ponded infiltration conditions. TF， TG and TH reduced the infiltration time by 29.6%， -0.8% and 40.0%， respectively， compared to CK. TF and TH could significantly reduce the infiltration time （P<0.05）. The effect of TF and TG on cumulative infiltration was not significant， while TH significantly reduced cumulative infiltration （P<0.05）. The sand incorporation pattern had a significant effect on both the wetting front and the cumulative infiltration. The cumulative evaporation of TF， TG and TH increased by -17.47%， -1.89% and 40.82%， respectively， compared to CK over 214 d. TH significantly increased soil water evaporation loss （P<0.05）， TF significantly inhibited soil evaporation （P<0.05） and TG had no significant effect on soil evaporation. Considering the current situation of water shortage in the region， the agronomic management measure of surface layer of sand mulch was recommended in filmless cultivation of crops in southern Xinjiang by taking integrating the characteristics of water movement under different modes of soil sand mixing into acount.

Key words: HYDRUS-1D, infiltration, inversion, evaporation, simulation, aeolian sand

摘要：

风蚀荒漠与绿洲农田是新疆旱区地表景观的典型表现，水资源短缺成为当地农业发展的重要限制因素。为揭示土壤不同掺沙模式下的水分运动规律，基于积水入渗试验，结合HYDRUS-1D软件，以均质壤土为对照（CK），对土壤表层覆沙（TF）、深层埋沙（TG）、浅层混沙（TH）3种土壤掺沙模式下的水分迁移特性进行研究。结果表明，累计入渗量实测值与模拟值之间吻合度较好，决定系数（R²）在0.998 1~0.999 3，均方根误差（root mean square error， RMSE）在0.135 3~0.220 4，基于HYDRUS-1D数值模型对积水入渗条件下土壤水力参数进行反演具有较好的适用性与较高的可靠性。TF、TG、TH入渗历时分别比CK时间缩短29.6%、-0.8%、40.0%，TF与TH均能显著减少入渗时间（P<0.05），TF与TG对累计入渗量影响差异不显著，TH可以显著降低累计入渗量（P<0.05）。土壤掺沙模式对湿润锋与累计入渗量均有显著影响。历时214 d，TF、TG与TH的累计蒸发量分别较CK提高-17.47%、-1.89%、40.82%。TH能显著提高土壤水分蒸发散失量（P<0.05），TF能显著抑制土壤蒸发（P<0.05），TG对土壤蒸发的作用不明显。考虑到地区水资源短缺的现状，综合土壤不同掺沙模式下水分运动特性，推荐在南疆地区无膜栽培作物种植应用表层覆沙的农艺管理措施。

关键词: HYDRUS-1D, 入渗, 反演, 蒸发, 模拟, 荒漠沙