| 摘要: |
| [目的]频率分析是估计水利水电工程设计洪水的主要方法,也是工程水文学的重要组成部分,一般采用与经验点据拟合较好的曲线来估计洪水设计值,其曲线参数的求解和适线准则密切相关,参数的计算精度直接影响着设计值.[方法]按照离(残)差平方和最小、离(残)差绝对值和最小、相对离(残)差平方和最小为适线准则,应用最小一乘法、最小二乘法和非线性模型参数估计改进法,进行了水文频率曲线参数的优化计算研究.[结果]通过实例验证,非线性模型参数估计法通过计算机反复的数值求解,可提高水文频率曲线的估计精度,避免了传统经验适线法的人为主观性.[结论]详细给出了规范(SL44-93)优化适线法离均系数以及对偏态系数的偏导数矩阵实用数值方法,这些方法可用于实际水文频率的分析计算. |
| 关键词: 水文频率 参数估算 非线性模型 |
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| 基金项目:国家自然科学基金项目（50579065）；西北农林科技大学青年学术骨干支持计划项目;西北农林科技大学优秀博士论文基金项目 |
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| Parameter optimum estimation for hydrological frequency curve |
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| Abstract: |
| 【Objective】 Hydrological frequency analysis is a main design method for water resources projects and an important part of engineering hydrology.The design values are estimated by a better fitting curve related to observed data.Its curve parameters are closely related to fitting curve criterion.Parameters precision has direct influence on design values.【Method】 According to least residual error quadratic sum and least residual error absolute sum and least relative residual error quadratic sum,parameter optimum estimation for hydrological frequency is done by least absolute sum and least square method and modified nonparametric estimation method of nonlinear model.【Result】 Examples of these methods indicate that nonparametric estimation method of nonlinear model can improve the precision of hydrological frequency curve and avoid subjectivity in empirical fitting by computer iterations.【Conclusion】 A detailed method of frequency factor for optimum fitting curve in SL44-93 Criterion and practical numerical iteration of partial derivative matrix for skewed coefficient are presented. These methods can be used in practical hydrological frequency analysis. |
| Key words: hydrological frequency parameter estimation nonlinear model |
