松嫩平原西部盐渍荒漠化机理研究

Research of Mechanism of Saline Desertification in Western Songnen Plain

选择松嫩平原西部盐碱化程度最高的大安市叉干镇明乐村,研究碱斑地的蒸散过程、土壤水分入渗过程,以及盐分运移和水盐平衡规律,进一步探讨该地区盐渍荒漠化的形成机理。结果表明:碱斑地没有植被覆盖,蒸散过程以土壤蒸发为主,水分运动带动盐分大量向土表积累;碱斑地土壤水分入渗率低,下行盐分远远小于上行盐分。土壤表层盐分累积的结果,使得该地区的草地景观退化,碱斑地面积增加,导致盐渍荒漠化程度加剧。

Mingle,a village of Chagan town in Daan city where all the arable lands are saline soil,and the salinization degree is the most in western Songnen plain,was selected as the experiment site. By researching the evapo-transpiration process of alkali-spot land, the soil water penetrating process, salts movement and water-salts balance laws, the mechanism of saline desertification was then discussed and discovered. The result is that the evapo-transpiration of alkali-spot land primarily is the soil evaporation without plants cover, and salts concentration in surface soil with water evaporation. The soil water infiltration in alkali-spot land is very low, so moved-down salts are much less than those moved up. The salts concentration in surface soil lets the grass landscape degradation, and increases the area of alkali-spot lands, which all exacerbating the saline desertification of this district.