| 1. |
- Du, Yiheng, et al.
(författare)
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Application-based evaluation of multi-basin hydrological models
- 2024
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Ingår i: Journal of Hydrology. - 0022-1694. ; 641
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Tidskriftsartikel (refereegranskat)abstract
- Hydrological models are generally calibrated and validated using a suite of well-known statistical metrics, which sometimes lack clear connection and tailoring to the local users’ need and therefore limits the evaluation, especially in the case of global climate services. Therefore, in this study, two types of application-based evaluation metrics are introduced, addressing (i) temporal matching of quantile extremes and (ii) relative bias in flow signatures, which supplements commonly used model performance assessment metrics. The introduced metrics are compared to conventional statistical metrics, at seven case study areas across the world, with three model settings representing different datasets and calibrations, generated from the global hydrological model World-Wide HYPE (WW HYPE). The results suggest that different performance results can occur when comparing application-based metrics to conventional ones. This implies that different evaluation metrics reveal models’ capability in various aspects, supporting their application under the corresponding circumstances. Finally, these metrics enable us to propose two model applicability scenarios: generally applicable models and conditionally applicable models. For instance, the WW HYPE with global dataset and local calibration can yield optimal estimates concerning the timing of quantile extremes and temporal variations in flow signatures, despite its suboptimal performance in conventional evaluation metrics. Therefore, it may be considered as a conditionally applicable model which can be used in regions with limited local datasets, supplying reliable information for decision-makers in formulating strategic plans for water resources management.
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| 2. |
- Nyberg, Lars, et al.
(författare)
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New data sources for cloudburst risk assessment and management
- 2022
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Ingår i: Vatten: tidskrift för vattenvård /Journal of Water Management and research. - 0042-2886. ; 78:2
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Urban flooding causes large societal damages and increased climate adaptation measures is needed. Therapid and local character of extreme rain events make them difficult to observe and predict, and to issuewarnings for. There is also a lack of data on urban flood damages, mainly because of scarce and nonsystematic data collection and management. In this paper, we present the approaches behind the new research project SPARC. The overarching aim of the project is to improve urban rain safety by establishinga participatory system for crowdsourcing of data, to support urban flood risk modelling and adaptation ofcities to intense rainfall. The project will also investigate flood damage mechanisms on the built environment as well as evaluate and communicate small-scale adaptation measures. Municipal water and wastewater utility organizations and insurance industry representatives will be included in a trans-disciplinaryprocess, also including crowdsourcing in a citizen science approach.
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| 3. |
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| 4. |
- Olsson, Jonas, et al.
(författare)
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Nonlinear and scaling spatial properties of soil geochemical element contents
- 2001
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Ingår i: Water Resources Research. - 0043-1397. ; 37:4, s. 1031-1042
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Tidskriftsartikel (refereegranskat)abstract
- The present study aimed at investigating whether a nonlinear and scaling approach is suitable for statistically characterizing the spatial variability of soil geochemical element contents at field conditions. Spatial distributions of 20 soil geochemical elements' contents in an agricultural field soil were investigated. Two indicators of nonlinear scaling were employed, empirical probability distribution functions (pdfs) and structure functions. For the pdfs, a trend was discovered with major elements naturally occurring in the soil being hyperbolic and minor trace elements being close to Gaussian. Further, fertilizer management was found to modify the behavior of related elements. The structure functions were generally nonscaling for major elements and scaling for minor elements, however, without any noticeable effect of fertilizer application. The scaling was of both monoaffine and multiaffine type. This suggests that the random cascade models recently used within geophysics may be useful also for geochemical element variability in soil.
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| 5. |
- Sivakumar, B., et al.
(författare)
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Preuve de l’0existence de chaos dans le processus pluie-débit
- 2001
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Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 46:1, s. 131-145
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Tidskriftsartikel (refereegranskat)abstract
- The transformation of rainfall into runoff is one of the most important processes in hydrology. In the past few decades, a wide variety of automated or computer-based approaches have been applied to model this process. However, many such approaches have an important limitation in that they treat the rainfall-runoff process as a realization of only a few parameters of linear relationships rather than the process as a whole. What is required, therefore, is an approach that can capture not only the overall appearance but also the intricate details of the nonlinear behaviour of the process. The purpose of this study is to investigate the possibility of understanding the dynamics of the rainfall-runoff process from a new perspective, as a chaotic process. The possible existence of chaotic behaviour in the rainfall-runoff process is studied by investigating the rainfall and runoff time series: (a) separately; and (b) jointly (using the runoff coefficient). Monthly rainfall and runoff observed over a period of 131 years (January 1807-December 1937) at the Göta River basin in the south of Sweden are analysed. The correlation dimension method is employed to identify the presence of chaos. The correlation dimensions obtained for the rainfall and runoff time series are 6.4 and 5.5, respectively. The finite dimensions obtained for the rainfall and runoff time series indicate the possible existence of chaos in these processes, implying that the joint rainfall-runoff process might also exhibit chaotic behaviour. The correlation dimension of about 7.8 obtained for the runoff coefficient also indicates the possible presence of chaos and supports the above results.
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| 6. |
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| 7. |
- South, Nicholas, et al.
(författare)
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Väderradarteknik inom VA-området : Test av metodik
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The report consists of a literature study of X-band weather radar technology, a comparison of rain data between an X-band radar facility near Lund and rain gauges, an analysis of flow- and sewage overflow data during rain events and implementation ideas of the X-band radar.
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