中文摘要：

为解决无水文资料地区水文计算的难题，科学客观地选择参证流域，针对4种参证流域选择的定量分析法：灰色分析法、模糊分析法、投影寻踪法和集对分析法，结合实际案例，探讨了其实质、特点及其优缺点。结果表明：4种方法的原理和处理手段存在差异，因其具有统一的客观评价基础，最终结果是一致的，因此4种方法具有普遍适用性，在实际工作中，使用者可根据资料条件和爱好选择使用。

英文摘要：

Long-term hydrologic prediction in ungauged basins is one of critical issues in the field of hydrologic calculations.Hydrologic analogy is an important method for long-term hydrologic prediction and hydrologic calculation in ungauged basins.The key point of hydrologic analogy is how to select a reference basin.This paper systematically discusses four popular methods for selecting a reference basin in China, which include grey analysis, fuzzy analysis, projection pursuit （ PP） and set pair analysis.Through a case study in small basins in Hebei Province, the four methods are applied in the selection of a reference basin.The advantages and disadvantages of these methods are explored, respectively.The results indicate that all these four methods can be used in selecting a reference basin.It depends on user＇s familiarity with one specific method and the experiences of the user.