水文相似概念与理论发展探析

Advances in the theories of hydrologic similarity: A discussion

目前,工程水文领域面临诸多问题有待解决,例如怎样合理地将现有水文观测成果外推至无资料流域,这也成为国际水文科学协会"无测站流域水文预测计划(PUB)"所遭遇的理论瓶颈。一个可行的方法就是依据流域结构特征构建水文相似因子,并对流域进行分类,在相似框架下完成观测成果向无(缺)测站流域的转化。分析发现,水文学缺乏类似于水力学、化学和生物学的分类与相似理论体系。通过对不同学科相似理论的回顾,定义了水文相似的概念,给出了构成流域水文相似的三要素,即驱动力、结构和水动力要素。最后,讨论了可用于水文相似研究的两类方法:数理解析法和量纲分析法,并给出了其用于实际流域水文相似研究时存在的问题及解决途径。

Nowadays, engineering hydrology is facing many challenges such as the extrapolation or regionalization of the observations of watershed behaviors. The difficulties in producing concise, easily understood explanations of watershed behaviors have been considered as a theoretical bottleneck by the Prediction in Ungaged Basins （PUB） of the International Association of Hydrological Sciences （IAHS）. An applicable solution is to develop a classification system based on dimensionless similarity indices, group watersheds into distinct groups, and then transfer observed results from gauged to ungaged basins under the frame of hydrologic similarity. In this study, it is found that hydrology does not have a theoretical system of classification and similarity as hydraulics, chemistry and biology, etc. By reviewing and comparing the similarity theory in other disciplines, we discussed the concept of hydrologic similarity, its basic methodology and three primary components, i. e. , driving, structural, and hydrodynamic factors. Finally, two useful methods for hydrologic similarity （mathematical and dimensional analysis） as well as the future directions are discussed.