Assessment of regional inter-basin groundwater flow using both simple and highly parameterized optimization schemes

Mehrdis Danapour,Anker Lajer Højberg,Karsten Høgh Jensen,Simon Stisen

doi:10.1007/s10040-019-01984-3

Mehrdis Danapour, Anker Lajer Højberg + Show 2 more

Open Access

https://doi.org/10.1007/s10040-019-01984-3

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Abstract

The need for regional-scale integrated hydrological models for the purpose of water resource management is increasing. Distributed physically based coupled surface-subsurface models are usually complex and contain a large amount of spatio-temporal information that leads to a relatively long forward runtime. One of the main challenges with regard to regional-scale inverse modeling relates to parameterization and how to adequately exploit the information embedded in the existing observational data while avoiding parameter identifiability issues. This study examined and compared the calibration of a “highly parameterized” model with a “classical” unit-based parameterization scheme in which the dominant geological features were assumed to be known. The physically based coupled surface-subsurface model MIKE SHE was used for conducting the study of five river basins (4,900 km2) in central Jutland in Denmark, characterized by heterogeneous geology and a considerable amount of groundwater flux across topographical catchment boundaries. The results indicated that introducing more flexibility in the parameter estimation process through a regularized approach significantly improved the model performance, in particular head and water balance errors. The highly parameterized calibration results additionally provided very useful insights into the model deficiencies in terms of conceptual model structure and incorrectly imposed boundary conditions. Furthermore, the results from data-worth analysis indicated that the highly parameterized model has more effectively utilized the information in the dataset compared to a traditional unit-based calibration approach.

Highlights

Water resources are under increasing pressure due to rapidly growing demands and climate change that has led to an increased competition between ecosystems and socioeconomic sectors (UNESCO 2012)
Unit-D is compared with unit-based calibration approach (unit-B) and pilot-D with pilotB, as their initial errors are the same, and further, the final Ф values are normalized to the initial values (Table 3)
The results showed that the RMSE of all four layers in both pilot-point-based calibration approaches are lower compared to both unit-based calibration approaches

Summary

Introduction

Water resources are under increasing pressure due to rapidly growing demands and climate change that has led to an increased competition between ecosystems and socioeconomic sectors (UNESCO 2012). There is a growing demand for management at the regional scale, since only at this scale can the economic, environmental and social problems that are linked to water resources be analyzed and solved in an integrated approach (Barthel and Banzhaf 2016). The application of such models, in particular at regional scale, is limited by the understanding of the physical system, data availability, and computational capacity (Barthel and Banzhaf 2016). Another important challenge with regard to integrated-water-resource-management, in particular at the regional scale, is that most of the currently

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