从土壤水动力学到生态水文学的发展与展望

Research advances from soil water dynamics to ecohydrology

在20世纪80年代,土壤水动力学成为我国水文水资源领域的一个新兴研究方向。在此后的30多年中,土壤水动力学得到了巨大发展,并对我国农田水利、水文水资源等领域的科学与技术起到了巨大的推动作用。以土壤水动力学为基础,逐步认识了非饱和土壤中水分与热量、溶质等耦合运移机理与规律,在20世纪90年代发展了土壤-作物-大气之间的水热交换和传输理论(即土壤-植物-大气连续体理论,简称SPAC理论)。以SPAC理论为基础,农田作物模型得到了快速发展,成为本世纪研究气候变化对农业水资源和粮食生产影响的主要工具。与此同时,从农田到区域的水转化机理与规律、不同尺度的农业用水效率、以及水资源开发利用的生态和环境影响等基础科学问题和生产实践问题逐渐被重视,从而形成了新的交叉学科——生态水文学。生态水文学以水分-能量-物质耦合循环的动力学过程为基础,注重区域气候-植被/作物-水文相互作用的基础科学问题,旨在为区域水资源、生态和环境评价与管理提供科学依据。

Soil water dynamics has been a new research field in hydrology and water resources since the 1980 s. Research progresses in soil water dynamics achieved in the past decades greatly promoted the ad-vances of sciences and technologies in the fields of irrigation and drainage,hydrology and water resourcesin China. Based on the soil water dynamics,the mechanism and laws of the water-heat-solute transfer in the unsaturated zone were revealed and understood. The theory of water and heat transfer in the Soil Plant Atmosphere Continuum（SPAC） was developed in 1990s（so called SPAC theory）. The field scale cropmodel was developed rapidly based on SPAC theory,and the crop models became the major tool for studythe impacts of climate change on agricultural water management and food production in the 21 st century.At the same time,a number of scientific and practical issues were raised,such as the water transfer cross-ing the field scale to regional scale,multi-scale efficiency of the agricultural water utilization,ecologicaland environmental impacts of water resources development and utilization and so on. To solve these urgentissues and challenges,a new cross discipline of hydrology and ecology has been proposed,it is ecohydrolo-gy. Ecohydrology is based on the dynamics of water-energy-substance cycle,focuses on the basic scientificquestion of the climate-vegetation-hydrology interaction,and aims to serve the regional water resources man-agement and eco-environment assessment and management.