冻融对长白山暗棕色森林土土壤水分传输过程的影响研究

Frozen soil, as one important components of cryosphere, spreads widely in global middle and high latitudes regions and low latitudes alpine areas, and has critical influence on regional even global climate, water cycle and water balance. The process of freezing and thawing resulted from the evolution of frozen soil changes soil physical properties as well as driving forces of water movement and increases the variability and uncertainty of soil water transportation, which lead to the hydrology process of frozen soil unique and becoming one of the research hotspots and difficulties in the fields of ecology, hydrology and climate. Recent researches have made some achievements on the changes of frozen soil layers, the influence of frozen soil on water infiltration, heat and water exchange of frozen soil. However, researches on the effect of priority flow channel resulted from inhomogeneous process of freezing and thawing on surface water, soil water and underground water, and quantifying the water-holding capacity in frozen layer and its water source were limited. In this study, the typical seasonal frozen soil of the main forest types of mid-temperate moist climate region in northeast China-broad-leaved and Korean pine in Changbai Mountain was chose as the research object, and the evolution of frozen soil layer, water table, snow depth, soil porosity and each component of water balance were measured at slope scale to illustrate the effect of variability in active layer of frozen soil on the vertical transportation process of soil water and its mechanism to interflow and overland flow, and to reveal the mechanism of transformation process of surface water, soil water and underground water in seasonal frozen soil and to develop hydrology, soil physics and forest soil science.

冻土尤其是季节性冻土对区域乃至全球气候、水循环等产生巨大影响，而造成冻土演变的冻融过程，改变土壤物理特性及其水分运动驱动力，增加土壤水分传输的变异性和不确定性，使冻土水文过程具有独特性，并成为生态、水文和气候等领域研究热点、也是难点。目前的研究在冻土层变化、冻土影响水分入渗、冻土水热交换等方面取得一定成果。但在冻融不均匀形成的优先流通道对地表水、土壤水与地下水"三水"转换的影响，以及冻结层蓄水动态及其水分来源的量化尚存不足。本研究以我国东北中温带湿润气候区最主要的森林类型-长白山阔叶红松林的典型季节性冻土为研究对象，在坡面尺度上监测土壤冻层演变、潜水位、积雪深度、土壤孔隙和水量平衡各分项，阐明冻土活动层变异性对土壤水分垂向传输过程、壤中流与坡面流的作用机制，揭示季节性冻土影响"三水"转换过程机理，发展水文学、土壤物理学与森林土壤学。

冻土尤其是季节性冻土对区域乃至全球气候、水循环等产生巨大影响，而造成冻土演变的冻融过程，改变土壤物理特性及其水分运动驱动力，增加土壤水分传输的变异性和不确定性，使冻土水文过程具有独特性，并成为生态、水文和气候等领域研究热点、也是难点。目前的研究在冻土层变化、冻土影响水分入渗、冻土水热交换等方面取得一定成果。但在冻融不均匀形成的优先流通道对地表水、土壤水与地下水“三水”转换的影响，以及冻结层蓄水动态及其水分来源的量化尚存不足。本研究以我国东北中温带湿润气候区最主要的森林类型—长白山阔叶红松林的典型季节性冻土为研究对象，在坡面尺度上监测土壤冻层演变、潜水位、积雪深度、土壤孔隙和水量平衡各分项，阐明冻土活动层变异性对土壤水分垂向传输过程、壤中流与坡面流的作用机制，揭示季节性冻土影响“三水”转换过程机理，发展水文学、土壤物理学与森林土壤学。