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塔克拉玛干沙漠公路防护林采用2.58~29.70 g·L-1高矿化度地下水滴灌,流沙压埋和水盐胁迫均是其面临的主要问题.探讨流沙压埋对土壤水分蒸发、盐分表聚及其分布的影响,对节水抑盐和指导干旱沙区水土资源的合理利用具有重要意义.采用微型蒸发器(MLS)研究了不同厚度沙埋下土壤蒸发及其水盐动态,并采用田间控制试验研究了滴管带不同厚度流沙压埋下土壤水盐分布状况.结果表明:1~5 cm沙埋下,MLS土壤日蒸发量和累积蒸发量均随沙埋厚度的增加而逐渐降低,累积蒸发量比对照降低2.5%~13.7%,土壤水分蒸发抑制效率随着沙埋厚度的增加而增高,1~5 cm厚度的沙埋蒸发抑制效率达16.7%~79.0%,流沙压埋界面以下土壤最终含水量随沙埋厚度的增加而增大,比对照增加2.5%~13.7%.随着沙埋厚度的增加,MLS内流沙表层电导率逐渐降低,分别降低1.19~6.00mS·cm-1,而压埋界面以下土壤盐分含量逐渐增加,且流沙表层盐分的变幅大于压埋界面以下土层.咸水滴灌条件下,流沙压埋界面以下土壤含水量随着压埋厚度的增加而增大,分别增加0.4%~2.0%;流沙表层积盐量随着流沙压埋厚度的增加呈先增后减的趋势,流沙压埋厚度为10 cm时最高,电导率达7.77 mS·cm-1,流沙压埋界面以下土层含盐量均远低于流沙浅层,35 cm可作为节水抑盐的临界流沙压埋厚度.流沙压埋对土壤水分蒸发和盐分表聚抑制作用极为明显,在干旱沙漠区,可以利用流沙压埋这一自然灾害,达到减蒸抑盐、变害为利的目的.
The Taklimakan Desert Highway Shelterbelt is a major problem in 2.58 ~ 29.70 g · L-1 high salinity groundwater drip irrigation, quicksand embedding and water and salt stress, and discusses the effects of sand infiltration on soil water evaporation, salt accumulation and distribution Is of great significance to water saving and salt suppression and to the rational utilization of water and soil resources in the arid sand area.The soil evaporation and its water and salt dynamics under different thickness sand were studied by micro-evaporator (MLS), and field control experiments were conducted The distribution of soil water and salinity under drip irrigation with different thickness of quicksand pressure was studied.The results showed that the MLS evaporation intensity and cumulative evaporation of MLS decreased with the increase of sand burial depth under 1 ~ Compared with the control, the inhibition efficiency decreased by 2.5% -13.7%. The inhibition efficiency of soil water evaporation increased with the increase of sand burial thickness. The inhibition efficiency of sand burial with 1 ~ 5 cm thickness reached 16.7% ~ 79.0% With the sand burial thickness increasing, increasing 2.5% ~ 13.7% than the control.With the increase of sand burial thickness, the surface conductivity of sediment in MLS decreased gradually, decreasing 1.19 ~ 6.00mS · cm-1, Buried below the interface soil salt content , And the change of salinity of quicksand surface is greater than that of the soil below the embedment interface.Under saline water drip irrigation, the soil moisture content below the embankment interface increases with the increase of embedment thickness by 0.4% -2.0% ; The surface sediment concentration of quicksand increases first and then decreases with the increase of the thickness of sand-flow embankment; the highest sand-pressure embankment thickness is 10 cm, the conductivity is 7.77 mS · cm-1; The salt content is much lower than that of the quicksand and 35 cm can be used as the threshold for quicksand and flowering of water-saving and salt-tolerant sediments. The effect of sand-flow embedding on soil water evaporation and salt accumulation is extremely obvious. In the arid desert area, Buried this natural disaster, to reduce the salt and suppress harm, change for the benefit of the purpose.