Inverse distributed hydrological modelling of Alpine catchments
Inverse distributed hydrological modelling of Alpine catchments
复制标题
高山流域的逆分布水文模型
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
S. Mayr
中科院分区：
文献类型：
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作者：
H. Kunstmann;J. Krause;S. Mayr
抽象的。即使在基于物理的分布式水文模型中，也必须对每个子集水区的各种剩余参数进行估计。这可能涉及巨大的努力，特别是当子集水区的数量很大，所应用的水文模型是计算昂贵的。自动参数估计工具可以显著地促进校准过程。因此，我们结合非线性参数估计工具PEST与分布式水文模型WaSiM。PEST基于Gauss-Marquardt-Levenberg方法，一种基于梯度的非线性参数估计算法。WaSiM是一个完全分布式的水文模型，使用基于物理的算法进行大部分过程描述。WaSiM应用于高山/高山前的阿默尔河流域（德国南部，710平方公里，水平分辨率为100×100平方米）。该流域在地质、土壤学和土地利用方面是异质的，并显示出复杂的地形（高差约为1600米）。使用开发的PEST-WaSiM接口，水文模型进行了校准，通过比较模拟和观测的径流在8个测量水文年1997年和验证的水文年1993年。对于每个子集水区的四个参数进行了校准：直接径流和interflow，排水密度和最上层含水层的水力传导系数的衰退常数。此外，五个融雪特定参数进行了调整，为整个集水区。总共需要校准37个参数。额外的先验信息（如洪水过程线分析）缩小了解的参数空间，并改善了拟合值的非唯一性。达到了合理的配合质量。模拟径流和观测径流之间的差异也是由于少数气象站和相应的插值人工制品在地形复杂的地形。与简单的地下水概念方法相比，二维地下水数值模型的应用部分导致整体模型性能略有下降。因此，增加模型的复杂性并不能提高模型的性能。进行了详细的协方差分析，以推导出所有估计参数的置信区间。在大多数情况下，估计参数之间的相关性可忽略不计，表明参数是相互独立估计的。
Abstract. Even in physically based distributed hydrological models, various remaining parameters must be estimated for each sub-catchment. This can involve tremendous effort, especially when the number of sub-catchments is large and the applied hydrological model is computationally expensive. Automatic parameter estimation tools can significantly facilitate the calibration process. Hence, we combined the nonlinear parameter estimation tool PEST with the distributed hydrological model WaSiM. PEST is based on the Gauss-Marquardt-Levenberg method, a gradient-based nonlinear parameter estimation algorithm. WaSiM is a fully distributed hydrological model using physically based algorithms for most of the process descriptions. WaSiM was applied to the alpine/prealpine Ammer River catchment (southern Germany, 710 km2 in a 100×100 m2 horizontal resolution. The catchment is heterogeneous in terms of geology, pedology and land use and shows a complex orography (the difference of elevation is around 1600 m). Using the developed PEST-WaSiM interface, the hydrological model was calibrated by comparing simulated and observed runoff at eight gauges for the hydrologic year 1997 and validated for the hydrologic year 1993. For each sub-catchment four parameters had to be calibrated: the recession constants of direct runoff and interflow, the drainage density, and the hydraulic conductivity of the uppermost aquifer. Additionally, five snowmelt specific parameters were adjusted for the entire catchment. Altogether, 37 parameters had to be calibrated. Additional a priori information (e.g. from flood hydrograph analysis) narrowed the parameter space of the solutions and improved the non-uniqueness of the fitted values. A reasonable quality of fit was achieved. Discrepancies between modelled and observed runoff were also due to the small number of meteorological stations and corresponding interpolation artefacts in the orographically complex terrain. Application of a 2-dimensional numerical groundwater model partly yielded a slight decrease of overall model performance when compared to a simple conceptual groundwater approach. Increased model complexity therefore did not yield in general increased model performance. A detailed covariance analysis was performed allowing to derive confidence bounds for all estimated parameters. The correlation between the estimated parameters was in most cases negligible, showing that parameters were estimated independently from each other.