不同类型盐荒地蒸发能力与水盐变化特征研究

Research on the Evaporation Capacity and Water-Salt Variation Characteristics of Different Types of Saline Wasteland

盐荒地通过强烈蒸发产生的干排作用是干旱半干旱灌区土壤盐分均衡和盐渍化防治的重要途径。为探究盐荒地的利用方式对干排作用的影响,本研究以内蒙古河套灌区为背景,在同一地点选择木本、草本、裸地三种植被类型盐荒地,开展了为期5个月的灌溉季节盐荒地蒸发能力与水盐变化特征的试验研究。结果表明,盐生植物不仅能够有效抑制盐荒地土壤表层的蒸发,还能够通过蒸腾作用促进土壤水分运动,使得土壤盐分在空间上分散,有效地发挥干排系统中盐荒地聚集盐分的能力。研究成果可为灌区干排水控盐系统的规划设计提供理论依据。

Dry drainage through intense evaporation from saline wasteland is an important way to control soil salinity in arid and semi-arid irrigation areas. In order to explore the effect of saline wasteland utilization on dry drainage, this paper selects three kinds of bare saline wasteland, covered with woody and herbaceous plants in the Hetao Irrigation District of Inner Mongolia respectively, and conducts a five-month observation of soil water and salt dynamics in the irrigation season of 2018. A soil water balance is made to evaluate the evapotranspiration from the saline wastelands. The results show that halophytes can effectively reduce the evaporation from the soil surface, promote soil water consumption from deep layers through transpiration and disperse salt in soil profile. It is proved that halophytes planting in saline wastelands can increase the evaporation capacity and prolong the service life of dry drainage system. These findings serve as a theoretical basis for planning and designing dry drainage system in arid irrigation areas.