基于分布式水文模型的水土保持水文水资源效应研究

Studies on effect of soil and water conservation on hydrology and water resources based on Distributed Hydrological Model

以往水土保持水文水资源效应研究所采取的方法均为水文法和水保法。由于这2种方法都不能系统地揭示水土保持对水循环影响的物理机制,并且采用的水资源评价口径只是单一的狭义水资源,使得研究成果不能真实反映水土保持的水文水资源效应。以狭义水资源和广义水资源为评价口径的基于物理机制的分布式水文模型则能克服水文法和水保法的严重弊端。评述分布式水文模型的研究进展;应用基于物理机制的分布式水文模型 (WEP-L模型),以黄河流域的重点水土流失治理区——河口镇至龙门区间为例,对水土保持的水文水资源效应进行定量研究。结果表明:水土保持使广义水资源量增加72．6亿m3,增幅27．1％;使狭义水资源量减少9．0亿m3,减幅14．4％;使狭义水资源的构成发生了变化,即地表水资源量减小、不重复量和地下水资源量增加。

Soil and water conservation benefits method and hydrological method are adopted in the previous studies on effect of soil and water conservation on hydrological and water resources. Because of water resources with narrow sense as assessment basis both of them can not systematically bring to light the physical mechanism of effect of soil and water conservation on hydrological cycle, so that the research achievements can not really reveal the effect of soil and water conservation on hydrological and water resources. Distributed hydrological model based on physical mechanism taking narrow and broad sense water resources as assessment basis can overcome their serious shortcomings. The research progress of distributed hydrological model is reviewed. Using the distributed hydrological model based on physical mechanism （WEP-L）, taking the key area of soil erosion control in the Yellow River basin, the area between Hekou and Longmen towns as a case, the effect of soil and water conservation on hydrological and water resources is quantitatively studied. The research results indicated that soil and water conservation enables absolute and relative amount of broad sense water resources increase by 7.26 billion m^3 and 27.1% respectively, and makes absolute and relative amount of narrow sense water resources to decrease by 0.90 billion m^3 and 14.4% respectively. Soil and water conservation changes the composition of narrow sense water resources, that is amount of surface water resources decreased, amount of unrepeated water resources and water ground water resources increased.