S. Kralisch - Academia.edu (original) (raw)
Papers by S. Kralisch
Managing a catchment for drinking water supply with a high proportion of agricultural land use ty... more Managing a catchment for drinking water supply with a high proportion of agricultural land use typically requires the maintenance of a reasonable balance between water quality demands and the costs for the resulting restrictions for the farming industry. A core part of this task therefore is multi-criterion decision making. Approaches to multi-criterion decision analysis often assume either a small number of alternative solutions to the decision problem or a simply structured solution space. For catchment management problems we can assume none of these properties: the consideration of lateral flows of substances affecting the water quality in the catchment results in highly complex solution spaces that have to be explored. Searching for an optimal solution of the problem in addition requires the consideration of a large number of solution candidates for the problem. This makes finding an optimal decision a practically intractable task. We present a method based on artificial neural ...
Journal of Hydrology, 2013
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
The need for integrating dynamic models with independently developed datasets and other models ha... more The need for integrating dynamic models with independently developed datasets and other models has long been recognized. Only recently, advances in modelling technologies, knowledge representation and protocols for remote communication of structured content have made this goal practical. The same advances make it possible to decouple the representation of a model from its executable implementation in ways that allow unprecedented levels of architecture independence and explicit, transportable model declaration. These developments are crucial to the creation of repositories of models where the models' lifetime is not tied to that of specific modelling paradigms, execution architectures, or storage technology. In this contribution, we describe a case study involving the declarative representation of model structure in a web-based knowledge base, its extraction through standard URLs as XML content, and the automated translation of the XML via dedicated components into source code models to be compiled for three different target architectures. We present the minimal declarative specification of the model interface and its key components, and discuss how it can be translated into executable form. We also describe the advantages of linking of each model component to explicit, external ontologies for matching model inputs and outputs to datasets and to other models. The advantages of the declarative specification are discussed in the light of ongoing, largescale projects in agricultural and biodiversity modelling.
Advances in Geosciences, 2007
The scientific sound definition of measures to achieve the goals of the EU water framework direct... more The scientific sound definition of measures to achieve the goals of the EU water framework directive (WFD) acquires spatially distributed analyses of the water and substance dynamics in meso-to macro-scale catchments. For this purpose, modelling tools or systems are needed which are robust and fast enough to be applied on such scales, but which are also able to simulate the impact of changes on single fields or small areas of a specific land use in the catchment. To face these challenges, we combined the fullydistributed hydrological model J2000 with the nitrogen transport routines of the Soil Water Assessment Tool SWAT model, which are normally applied in a semi-distributive approach. With this combination, we could extend the quantitative focus of J2000 with qualitative processes and could overcome the semi-distributed limitation of SWAT. For the implementation and combination of the components, we used the Jena Adaptable Modelling System JAMS (Kralisch and Krause, 2006) which helped tremendously in the relatively rapid and easy development of the new resultant model J2000-S (J2000-Substance). The modelling system was applied in the upper Gera watershed, located in Thuringia, Germany. The catchment has an area of 844 km 2 and includes three of the typical landscape forms of Thuringia. The application showed, that the new modelling system was able to reproduce the daily hydrological as well as the nitrogen dynamics with a sufficient quality. The paper will describe the results of the new model and compare them with the results obtained with the original semi-distributed application of SWAT.
Advances in Geosciences, 2005
State of the art challenges in sustainable management of water resources have created demand for ... more State of the art challenges in sustainable management of water resources have created demand for integrated, flexible and easy to use hydrological models which are able to simulate the quantitative and qualitative aspects of the hydrological cycle with a sufficient degree of certainty. Existing models which have been developed to fit these needs are often constrained to specific scales or purposes and thus can not be easily adapted to meet different challenges. As a solution for flexible and modularised model development and application, the Object Modeling System (OMS) has been developed in a joint approach by the USGS (Denver, Col.), the USDA (Fort Collins, Col.) and the FSU (Jena, Germany). The OMS provides a modern modelling framework which allows the implementation of single process components to be compiled and applied as custom tailored model assemblies. This paper describes briefly the OMS and its main components and explains more in detail how the problems during coupling of models or model components are solved inside the system. It highlights the integration of different spatial and temporal scales by their representation as spatial modelling entities embedded into time compound components. As an example the implementation of the hydrological model J2000 is discussed.
The European Water Framework Directive (EU-WFD), implemented in the year of 2000, requires genera... more The European Water Framework Directive (EU-WFD), implemented in the year of 2000, requires general ecological protection and a minimum chemical standard to be obtained in all European surface waters at different spatial and temporal scales. To meet these requirements the knowledge of spatially distributed sources and movements of contaminants, e.g. nutrients entries on stream systems is essential. In Germany some major water quality problems are related to non-point sources of nitrogen export. For a collaborative pilot study the need was identified to integrate solute turnover and transport processes into the object-oriented Java based JAMS modeling framework (Jena Adaptable Modelling System). The innovative potential of JAMS was enhanced to consider, describe and model hydrologic and solute processes within the appropriate spatial and temporal context. Moreover JAMS provides the possibility of exchanging process modules according to individual needs and problems. This paper will give a conceptual overview of the current developments on the implementation and integration of process modules for different nitrogen components and their turnover, and soil temperature and crop growth as well as options for land use management scenarios. The preliminary results of an application in a mesoscale catchment in Germany are also described.
Abstract: The analysis of parameter sensitivity in environmental models is an excellent technique... more Abstract: The analysis of parameter sensitivity in environmental models is an excellent technique to assess a model’s behavior, to determine its potential utility, to support its calibration, and to identify areas of improvement. Recent work on comparing sensitivity analysis methods shows that the methods available today are complementary, i.e. multi-ple methods should be used to assess a model. We present a software toolbox for global sensitivity analysis which supports the investigation of parameter sensitivity using differ-ent methods. The toolbox includes Regional Sensitivity Analysis, Morris Method, and a Sobols method. The majority of these methods require input data from a Monte-Carlo-Sampling which has to be carried out in advance, others demand for special properties of the sampling. Therefore, in most cases, huge computational effort has to be spent to generate several sampling data. To overcome this deficit the data from a single Monte-Carlo-Sampling is used to train an A...
natural resources management in Tasmania through spatially distributed solute modelling with JAMS... more natural resources management in Tasmania through spatially distributed solute modelling with JAMS/J2000-S
Investigating the impact of two decades of urbanization on the water balance of the Yzeron peri-u... more Investigating the impact of two decades of urbanization on the water balance of the Yzeron peri-urban catchment, France.
Abstract: Current challenges in sustainable management of water resources have created demand for... more Abstract: Current challenges in sustainable management of water resources have created demand for inte-grated, flexible and easy to use hydrological models which are able to simulate the quantitative and qualitative aspects of the hydrological cycle with a sufficient degree of certainty. Existing models which have been devel-oped to fit these needs are often constrained to specific scales or purposes and thus can not be easily adapted to meet different challenges. As a consequence resulting from this shortage a number of modelling frameworks have been developed, e.g. the Object Modelling System (OMS). In order to enhance the capabilities of OMS to-wards special demands from model developers we created the Jena Adaptable Modelling System (JAMS). Built on the basis of OMS, JAMS focuses especially on flexibility during the development of new model components and less on easy integration of existing ones. This paper will present an overview of the JAMS architecture and sketches the mode...
The catchment management of reservoirs for drinking water supply not only requires knowledge abou... more The catchment management of reservoirs for drinking water supply not only requires knowledge about the nitrogen discharge of every agricultural field. In order to recommend changes in land use management it is much more important to evaluate its influence to the nitrogen concentration in the reservoir. In order to achieve this the influence of processes that take place during transport must be considered.
Journal of Hydrology
Summary Flash floods represent one of the most destructive natural hazards in the Mediterranean r... more Summary Flash floods represent one of the most destructive natural hazards in the Mediterranean region. These floods result from very intense and spatially heterogeneous rainfall events. Distributed hydrological models are valuable tools to study these phenomena and increase our knowledge on the main processes governing the generation and propagation of floods over large spatial scales. They are generally built using a bottom–up approach that generalizes small-physics representations of processes. However, top–down or data-driven approach is increasingly shown to provide also valuable knowledge. A simplified semi-distributed continuous hydrological model, named SIMPLEFLOOD, was developed, based on the simple dynamical system approach (SDSA) proposed by Kirchner (WRR, 2009, 45, W02429), and applied to the Ardeche catchment in France (2388 km 2 ). This data-driven method assumes that discharge at the outlet of a given catchment can be expressed as a function only of catchment storage. It leads to a 3-parameter nonlinear model according to rainfall and runoff observations. This model was distributed over sub-catchments and coupled with a kinematic wave based flow propagation module. The parameters were estimated by discharge recession analyses at several gauged stations. Parameter regionalization was conducted using a Factorial Analysis of Mixed Data (FAMD) and Hierarchical Classification on Principal Component (HCPC) in order to find relationships between the SDSA approach and catchments characteristics. Geology was found to be the main predictor of hydrological response variability and model parameters were regionalized according to the dominant geology. The SIMPLEFLOOD model was applied for a 12-year continuous simulation over the Ardeche catchment. Four flash flood events were also selected for further analysis. The simulated hydrographs were compared with the observations at 11 gauging stations with catchment size ranging from 17 to 2300 km 2 . The results show a good performance of the model for the continuous and flash flood events occurring under wet conditions, whereas the model underestimates discharge for events occurring after a long dry period. The simple modeling approach provided interesting insight into the Ardeche catchment functioning and offers perspective for a better simulation of flash floods, mainly under wet conditions.
Transactions of the ASABE, 2012
ABSTRACT
In many cases, applications of water-quality models have a poor basis of calibration and validati... more In many cases, applications of water-quality models have a poor basis of calibration and validation due to limited or lack of input data. Water-quality monitoring often is limited to a few sites within the stream network at which samples are collected and analysed at some intermittent frequency (e. g. monthly). In particular, this limited temporal sample coverage causes problems in modelling water-quality variables such as phosphorous that are mainly transported during short-time events. The resultant loads calculated based upon these data are often subject to large errors, due to this sparse time resolution. In order to address this problem, a meso-scale catchment was equipped with a measurement network for obtaining spatially and temporally higher-resolution data. As test site, the upper catchment of the Gera River (approx. 850 km²) was selected for this study. The catchment features different landscape forms that are typical for middle mountainous regions in middle Europe. The measurement network consisted of six online water-quality stations and 23 additional water-quality sample points distributed in the river network. At these monitoring sites, streamflow, temperature, pH-Value, electrical conductivity, turbidity, suspended solids, dissolved oxygen, nitrate, ammonium, total phosphorous, total organic carbon and other variables were measured or analyzed in the laboratory. In addition, eight weather stations and 24 soil-moisture sites were installed on farm land distributed throughout the catchment. The goal of this study is to improve the existing components describing the hydrological, nitrogen loadings, and overall land-use management using the J-2000-S model with the measured data. These data will also help to implement an erosion-phosphorus component and a stream water-quality component for this particular model.
Managing a catchment for drinking water supply with a high proportion of agricultural land use ty... more Managing a catchment for drinking water supply with a high proportion of agricultural land use typically requires the maintenance of a reasonable balance between water quality demands and the costs for the resulting restrictions for the farming industry. A core part of this task therefore is multi-criterion decision making. Approaches to multi-criterion decision analysis often assume either a small number of alternative solutions to the decision problem or a simply structured solution space. For catchment management problems we can assume none of these properties: the consideration of lateral flows of substances affecting the water quality in the catchment results in highly complex solution spaces that have to be explored. Searching for an optimal solution of the problem in addition requires the consideration of a large number of solution candidates for the problem. This makes finding an optimal decision a practically intractable task. We present a method based on artificial neural ...
Journal of Hydrology, 2013
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
The need for integrating dynamic models with independently developed datasets and other models ha... more The need for integrating dynamic models with independently developed datasets and other models has long been recognized. Only recently, advances in modelling technologies, knowledge representation and protocols for remote communication of structured content have made this goal practical. The same advances make it possible to decouple the representation of a model from its executable implementation in ways that allow unprecedented levels of architecture independence and explicit, transportable model declaration. These developments are crucial to the creation of repositories of models where the models' lifetime is not tied to that of specific modelling paradigms, execution architectures, or storage technology. In this contribution, we describe a case study involving the declarative representation of model structure in a web-based knowledge base, its extraction through standard URLs as XML content, and the automated translation of the XML via dedicated components into source code models to be compiled for three different target architectures. We present the minimal declarative specification of the model interface and its key components, and discuss how it can be translated into executable form. We also describe the advantages of linking of each model component to explicit, external ontologies for matching model inputs and outputs to datasets and to other models. The advantages of the declarative specification are discussed in the light of ongoing, largescale projects in agricultural and biodiversity modelling.
Advances in Geosciences, 2007
The scientific sound definition of measures to achieve the goals of the EU water framework direct... more The scientific sound definition of measures to achieve the goals of the EU water framework directive (WFD) acquires spatially distributed analyses of the water and substance dynamics in meso-to macro-scale catchments. For this purpose, modelling tools or systems are needed which are robust and fast enough to be applied on such scales, but which are also able to simulate the impact of changes on single fields or small areas of a specific land use in the catchment. To face these challenges, we combined the fullydistributed hydrological model J2000 with the nitrogen transport routines of the Soil Water Assessment Tool SWAT model, which are normally applied in a semi-distributive approach. With this combination, we could extend the quantitative focus of J2000 with qualitative processes and could overcome the semi-distributed limitation of SWAT. For the implementation and combination of the components, we used the Jena Adaptable Modelling System JAMS (Kralisch and Krause, 2006) which helped tremendously in the relatively rapid and easy development of the new resultant model J2000-S (J2000-Substance). The modelling system was applied in the upper Gera watershed, located in Thuringia, Germany. The catchment has an area of 844 km 2 and includes three of the typical landscape forms of Thuringia. The application showed, that the new modelling system was able to reproduce the daily hydrological as well as the nitrogen dynamics with a sufficient quality. The paper will describe the results of the new model and compare them with the results obtained with the original semi-distributed application of SWAT.
Advances in Geosciences, 2005
State of the art challenges in sustainable management of water resources have created demand for ... more State of the art challenges in sustainable management of water resources have created demand for integrated, flexible and easy to use hydrological models which are able to simulate the quantitative and qualitative aspects of the hydrological cycle with a sufficient degree of certainty. Existing models which have been developed to fit these needs are often constrained to specific scales or purposes and thus can not be easily adapted to meet different challenges. As a solution for flexible and modularised model development and application, the Object Modeling System (OMS) has been developed in a joint approach by the USGS (Denver, Col.), the USDA (Fort Collins, Col.) and the FSU (Jena, Germany). The OMS provides a modern modelling framework which allows the implementation of single process components to be compiled and applied as custom tailored model assemblies. This paper describes briefly the OMS and its main components and explains more in detail how the problems during coupling of models or model components are solved inside the system. It highlights the integration of different spatial and temporal scales by their representation as spatial modelling entities embedded into time compound components. As an example the implementation of the hydrological model J2000 is discussed.
The European Water Framework Directive (EU-WFD), implemented in the year of 2000, requires genera... more The European Water Framework Directive (EU-WFD), implemented in the year of 2000, requires general ecological protection and a minimum chemical standard to be obtained in all European surface waters at different spatial and temporal scales. To meet these requirements the knowledge of spatially distributed sources and movements of contaminants, e.g. nutrients entries on stream systems is essential. In Germany some major water quality problems are related to non-point sources of nitrogen export. For a collaborative pilot study the need was identified to integrate solute turnover and transport processes into the object-oriented Java based JAMS modeling framework (Jena Adaptable Modelling System). The innovative potential of JAMS was enhanced to consider, describe and model hydrologic and solute processes within the appropriate spatial and temporal context. Moreover JAMS provides the possibility of exchanging process modules according to individual needs and problems. This paper will give a conceptual overview of the current developments on the implementation and integration of process modules for different nitrogen components and their turnover, and soil temperature and crop growth as well as options for land use management scenarios. The preliminary results of an application in a mesoscale catchment in Germany are also described.
Abstract: The analysis of parameter sensitivity in environmental models is an excellent technique... more Abstract: The analysis of parameter sensitivity in environmental models is an excellent technique to assess a model’s behavior, to determine its potential utility, to support its calibration, and to identify areas of improvement. Recent work on comparing sensitivity analysis methods shows that the methods available today are complementary, i.e. multi-ple methods should be used to assess a model. We present a software toolbox for global sensitivity analysis which supports the investigation of parameter sensitivity using differ-ent methods. The toolbox includes Regional Sensitivity Analysis, Morris Method, and a Sobols method. The majority of these methods require input data from a Monte-Carlo-Sampling which has to be carried out in advance, others demand for special properties of the sampling. Therefore, in most cases, huge computational effort has to be spent to generate several sampling data. To overcome this deficit the data from a single Monte-Carlo-Sampling is used to train an A...
natural resources management in Tasmania through spatially distributed solute modelling with JAMS... more natural resources management in Tasmania through spatially distributed solute modelling with JAMS/J2000-S
Investigating the impact of two decades of urbanization on the water balance of the Yzeron peri-u... more Investigating the impact of two decades of urbanization on the water balance of the Yzeron peri-urban catchment, France.
Abstract: Current challenges in sustainable management of water resources have created demand for... more Abstract: Current challenges in sustainable management of water resources have created demand for inte-grated, flexible and easy to use hydrological models which are able to simulate the quantitative and qualitative aspects of the hydrological cycle with a sufficient degree of certainty. Existing models which have been devel-oped to fit these needs are often constrained to specific scales or purposes and thus can not be easily adapted to meet different challenges. As a consequence resulting from this shortage a number of modelling frameworks have been developed, e.g. the Object Modelling System (OMS). In order to enhance the capabilities of OMS to-wards special demands from model developers we created the Jena Adaptable Modelling System (JAMS). Built on the basis of OMS, JAMS focuses especially on flexibility during the development of new model components and less on easy integration of existing ones. This paper will present an overview of the JAMS architecture and sketches the mode...
The catchment management of reservoirs for drinking water supply not only requires knowledge abou... more The catchment management of reservoirs for drinking water supply not only requires knowledge about the nitrogen discharge of every agricultural field. In order to recommend changes in land use management it is much more important to evaluate its influence to the nitrogen concentration in the reservoir. In order to achieve this the influence of processes that take place during transport must be considered.
Journal of Hydrology
Summary Flash floods represent one of the most destructive natural hazards in the Mediterranean r... more Summary Flash floods represent one of the most destructive natural hazards in the Mediterranean region. These floods result from very intense and spatially heterogeneous rainfall events. Distributed hydrological models are valuable tools to study these phenomena and increase our knowledge on the main processes governing the generation and propagation of floods over large spatial scales. They are generally built using a bottom–up approach that generalizes small-physics representations of processes. However, top–down or data-driven approach is increasingly shown to provide also valuable knowledge. A simplified semi-distributed continuous hydrological model, named SIMPLEFLOOD, was developed, based on the simple dynamical system approach (SDSA) proposed by Kirchner (WRR, 2009, 45, W02429), and applied to the Ardeche catchment in France (2388 km 2 ). This data-driven method assumes that discharge at the outlet of a given catchment can be expressed as a function only of catchment storage. It leads to a 3-parameter nonlinear model according to rainfall and runoff observations. This model was distributed over sub-catchments and coupled with a kinematic wave based flow propagation module. The parameters were estimated by discharge recession analyses at several gauged stations. Parameter regionalization was conducted using a Factorial Analysis of Mixed Data (FAMD) and Hierarchical Classification on Principal Component (HCPC) in order to find relationships between the SDSA approach and catchments characteristics. Geology was found to be the main predictor of hydrological response variability and model parameters were regionalized according to the dominant geology. The SIMPLEFLOOD model was applied for a 12-year continuous simulation over the Ardeche catchment. Four flash flood events were also selected for further analysis. The simulated hydrographs were compared with the observations at 11 gauging stations with catchment size ranging from 17 to 2300 km 2 . The results show a good performance of the model for the continuous and flash flood events occurring under wet conditions, whereas the model underestimates discharge for events occurring after a long dry period. The simple modeling approach provided interesting insight into the Ardeche catchment functioning and offers perspective for a better simulation of flash floods, mainly under wet conditions.
Transactions of the ASABE, 2012
ABSTRACT
In many cases, applications of water-quality models have a poor basis of calibration and validati... more In many cases, applications of water-quality models have a poor basis of calibration and validation due to limited or lack of input data. Water-quality monitoring often is limited to a few sites within the stream network at which samples are collected and analysed at some intermittent frequency (e. g. monthly). In particular, this limited temporal sample coverage causes problems in modelling water-quality variables such as phosphorous that are mainly transported during short-time events. The resultant loads calculated based upon these data are often subject to large errors, due to this sparse time resolution. In order to address this problem, a meso-scale catchment was equipped with a measurement network for obtaining spatially and temporally higher-resolution data. As test site, the upper catchment of the Gera River (approx. 850 km²) was selected for this study. The catchment features different landscape forms that are typical for middle mountainous regions in middle Europe. The measurement network consisted of six online water-quality stations and 23 additional water-quality sample points distributed in the river network. At these monitoring sites, streamflow, temperature, pH-Value, electrical conductivity, turbidity, suspended solids, dissolved oxygen, nitrate, ammonium, total phosphorous, total organic carbon and other variables were measured or analyzed in the laboratory. In addition, eight weather stations and 24 soil-moisture sites were installed on farm land distributed throughout the catchment. The goal of this study is to improve the existing components describing the hydrological, nitrogen loadings, and overall land-use management using the J-2000-S model with the measured data. These data will also help to implement an erosion-phosphorus component and a stream water-quality component for this particular model.