植被—土壤—水文相互作用及生态水文模型参数的动态表述

植被与土壤、水文之间存在复杂的相互作用,是生态水文模型和植被变化生态水文效应评估研究的重点.虽然陆面植被指数等动态变化对流域截留、蒸散发等水量、能量平衡项影响已有较多研究,但植被地下生物量变化如何改变土壤结构和水力特性,进而影响入渗和径流等水文过程研究相对缺乏.本文综述国内外植被变化对土壤、水文动态变化特征研究成果基础上,分析植被变化水文响应的阈值效应和尺度效应、植被变化下的土壤水力参数时变特征定量表述及其与植被、土壤类型以及气候条件的关系.在生态水文模型中,考虑植被因子对土壤水力参数影响的动态表达可以提高植被变化下水文效应模拟和预测的可靠性.

Vegetation-soil-hydrology interaction and expression of parameter variations in ecohydrological models

Complex interaction among vegetation,soil and hydrology is a key issue in ecohydrological modeling and in evaluation of vegetation effect on hydrological processes. Numerous researchers have investigated the effect of change in land surface vegetation index on interception and evapotranspiration (components of catchment energy and water balances ). Work has also been done on how changes in underground vegetation biomass would affect soil structure and hydraulic properties which in turn influence hydrological processes such as infiltration and runoff.Research on soil and hydrological variations related to vegetation changes is reviewed,scale effect of hydrological response to vegetation alteration,expression of time-varying features of soil hydraulic parameters,and their relation with vegetation types,soil properties and climate conditions are analyzed.Simulation and prediction reliability of vegetation change effect on hydrological processes should be improved if parameters of ecohydrological models are expressed by time-variation with vegetation indexes.