# Andreas H. SchumannRuhr-Universität Bochum | RUB · Working Group "Spate" (Spatial and temporal dynamics of extreme floods)

Andreas H. Schumann

Prof. Dr.

Retired professor, Speaker of the research group "Space-Time Dynamics of Extreme Floods (SPATE)"

## About

193

Publications

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Introduction

After my PhD I worked 8 years in practice in several water management authorities. Since this time I am very interested in solving practical probems and in developing hydrological tools which could be applied in practical water management. From my opinion, new methodologies should be reasoned by the needs of the society.

Additional affiliations

June 2017 - May 2020

October 2001 - present

## Publications

Publications (193)

Statistical distributions of flood peak discharge often show heavy tail behavior, that is, extreme floods are more likely to occur than would be predicted by commonly used distributions that have exponential asymptotic behavior. This heavy tail behavior may surprise flood managers and citizens, as human intuition tends to expect light tail behavior...

The regionalisation of flood frequencies is a precondition for the estimation of flood statistics for ungauged basins. It is often based on either the concept of hydrological similarity of catchments or spatial proximity. Similarity is usually defined by comparing catchment attributes or distances. Here, we apply flood types in regionalisation dire...

Eine HKC Projektgruppe hat praxisorientierte Hinweise zum Umgang mit hydrologischen Belastungsgrößen zur Ermittlung von Hochwassergefahren in einem Werkstattbericht erarbeitet. In Zeiten des Klimawandels nehmen die Starkniederschläge messbar zu. Somit verändern sich auch innerhalb von kurzer Zeit die Werte für die Wiederkehrwahrscheinlichkeiten. Da...

In contrast to the basic assumption of a homogeneous population underlying common approaches to flood frequency analysis, flood events often arise from different runoff‐generating processes. In many large river basins, the diversity of these processes within tributary basins and the superposition of their flood waves increase the complexity of stat...

Flood events may be caused by different runoff generating processes and can be differentiated in their genesis by the application of flood types. Additionally, the spatial interaction of catchments can play a crucial role in the flood generation. Flood wave superposition can increase the flood peak and volume downstream. The magnitude of increase a...

The classification of characteristics of flood events, like peak, volume, duration and baseflow components is essential for many hydrological applications such as multivariate flood statistics, the validation of rainfall-runoff models and comparative hydrology in general. The basis for estimations of these characteristics is formed by flood event s...

Grundkenntnisse in der Hydrologie und Wasserwirtschaft sind für die Planung, Bemessung, Bau und Betrieb baulicher wasserwirtschaftlicher Anlagen unverzichtbar. Hier werden insbesondere die Problematik der Hochwasserabflüsse und stochastische sowie deterministische Ansätze zu deren Quantifizierung behandelt. Die Komponenten des Wasserhaushaltes werd...

The optimization and extension of existing gauging networks is a challenging task, which can be done under consideration of many different aspects. One possibility is to maximize the obtained information on regional hydrological characteristics by new gauges compared to existing ones. For this, information theory approaches are most suitable. Here,...

Hydrological models used for flood prediction in ungauged catchments are commonly fitted to regionally transferred data. The key issue of this procedure is to identify hydrologically similar catchments. Therefore, the dominant controls for the process of interest have to be known. In this study, we applied a new machine learning based approach to i...

Floods which affect several macro-scale river basins simultaneously can cause devastating damage. Future flood-risk assessment depends significantly on the knowledge about the atmospheric conditions leading to floods and external climate drivers. Nonetheless, only a few studies have investigated widespread floods, their occurrence frequency, and th...

Agenten-basierte Modelle ermöglichen es, komplexe dynamische Systeme nachzubilden und werden häufig dort eingesetzt, wo das Verhalten und das Zusammenspiel einzelner Akteure von Wichtigkeit sind. Besonders in gekoppelten, sozio-hydrologischen Modellen ist dieser Modelltypus verbreitet. Agenten-basierte Modelle leiden jedoch unter der starken Abstra...

The flood peak is the dominating characteristic in nearly all flood-statistical analyses. Contrary to the general assumptions of design flood estimation, the peak is not closely related to other flood characteristics. Differentiation of floods into types provides a more realistic view. Often different parts of the probability distribution function...

Hochwasser richten enorme Schäden an. Trotz jahrzehntelanger Forschung überraschen sie uns immer noch in ihrer Wirkung, und ein besseres Verständnis ist von hoher humanitärer und monetärer Bedeutung. Statistik hilft mit Modellen und Verfahren zur Analyse des Risikos von Hochwasser und allgemeiner extremer Naturereignisse. Wir berichten über den Sta...

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through on-line media, followed by two workshops through which a large number of potential science questions were collated, p...

Flood events can have very different generating processes. Floods may originate from high intensity rainfall, long-duration rainfall or snowmelt. Other factors, e.g. initial soil moisture conditions, also affect the spatial and temporal characteristics of floods. Hence, a typology for floods is often used to classify floods according to their runof...

Flood events can have very different generating processes. Floods may originate from high intensity rainfall, long-duration rainfall or snowmelt. Other factors, e.g. initial soil moisture conditions, also affect the spatial and temporal characteristics of floods. Hence, a typology for floods is often used to classify floods according to their runof...

A wide variety of processes controls the time of occurrence, duration, extent, and severity of river floods. Classifying flood events by their causative processes may assist in enhancing the accuracy of local and regional flood frequency estimates and support the detection and interpretation of any changes in flood occurrence and magnitudes. This p...

Die Beschreibung komplexer Systeme benötigt Modellansätze, die in der Lage sind dynamische Interaktionen zu beschreiben und zudem chaotische Komponenten darstellen können, die durch wechselnde Wirkungszusammenhänge entstehen. Agenten-basierte Modelle ermöglichen es, komplexe dynamische Systeme nachzubilden und werden häufig dort eingesetzt, wo das...

The newly developed image interpretation approach of agent-based image classification combines the advantages of object-based image classification and expert knowledge. Agent-based classification identifies meaningful objects by autonomous software units that alter their spatial extent and composition to adapt to a changing environment and data ava...

Classification of floods is often based on return periods of their peaks estimated from probability distributions and hence depends on assumptions. The choice of an appropriate distribution function and parameter estimation are often connected with high uncertainties. In addition, limited length of data series and the stochastic characteristic of t...

Die Schätzung von Niederschlagsereignissen für gegebene Dauerstufen und Jährlichkeiten ist die Grundlage vieler wasserbaulicher Bemessungen der Kommunen, Länder und Verbände und ist durch das Merkblatt DWA A-531 geregelt. Dieses sieht eine Anpassung über die zweiparametrige Gumbel-Verteilung mit anschließendem Ausgleich über alle Dauerstufen vor. D...

Bei großen Hochwasserereignissen kommt es zur Überlagerung von Scheiteln aus verschiedenen Teileinzugsgebieten. Die Wirkung von Rückhaltesystemen kann mit Szenarien bewertet werden, die diese räumlichen Verhältnisse berücksichtigen. Dies erfordert die Einschätzung der Plausibilität der betrachteten Ereignisse, wofür die übliche Scheitelstatistik je...

Die Beurteilung von Hochwasserrückhaltungen erfolgt meist auf Grundlage einzelner Bemessungsereignisse. Derartige Ansätze können die Vielfalt möglicher Belastungsszenarien nicht repräsentieren. Insbesondere die Analyse der Schutzwirkung durch Speicher, die im Verbund bewirtschaftet werden, erfordert die umfassende Berücksichtigung raum-zeitlicher V...

In the last decade, agent-based modelling (ABM) became a popular modelling technique in social sciences, medicine, biology, and ecology. ABM was designed to simulate systems that are highly dynamic and sensitive to small variations in their composition and their state. As hydrological systems, and natural systems in general, often show dynamic and...

In the last decade, agent-based modelling (ABM) became a popular modelling technique in social sciences, medicine, biology and ecology. ABM was designed to simulate systems that are highly dynamic and sensitive to small variations in their composition and their state. As hydrological systems, and natural systems in general, often show dynamic and n...

In regional flood frequency analysis the homogeneity of a group of stations is an essential assumption. A standard procedure in hydrology to evaluate this condition is the homogeneity measure of Hosking and Wallis, which applies L-moments. Disadvantages of it are the lack of power when analysing highly skewed data and the implicit assumption of spa...

Over decades, the planning of flood management was based on a safety-oriented approach. A design flood was estimated by probabilistic means to specify the limit up to which a flood should be controlled completely by technical measures. A case of failure was expected only in such cases where the design flood is overtopped. As design floods were spec...

Driven by the EU-Flood Directive, flood risk management became one of the focusing points of water policy. Flood risk means the combination of the probability of a flood event with its adverse consequences. Unfortunately, the consequences of a changing environment on floods are hidden by high uncertainties about the stochastic behavior of flood ind...

A distributed or semi-distributed
deterministic hydrological model should consider the hydrologically most
relevant catchment characteristics. These are heterogeneously distributed
within a watershed but often interrelated and subject to a certain spatial
organization which results in archetypes of combined characteristics. In
order to reproduce th...

Ordinal patterns provide a method to measure dependencies between time series. In contrast to classical correlation measures like the Pearson correlation coefficient they are able to measure not only linear correlation but also non-linear correlation even in the presence of non-stationarity. Hence, they are a noteworthy alternative to the classical...

In widely-used flood statistics, annual maximum discharges are generally used as the basis for the calculation of quantiles as design
floods. These contain summer as well as winter events, each with a different genesis. Seasonal statistics offer one possibility of
coping with this. It is the goal of this article to expand the classical seasonal sta...

Ordinal patterns provide a method to measure correlation between time series. In contrast to classical correlation measures like the Pearson correlation coefficient they are able to measure not only linear correlation but also non-linear correlation even in the presence of non-stationarity. Hence, they are a noteworthy alternative to the classical...

Summarizing a series of rainfall events for different duration levels by their annual maxima provides
valuable information. These statistics are e.g. the design base of urban drainage systems. Investigating
an entire set of duration levels, the dependence among them has to be taken into account. We propose
an approach where a set of generalized ext...

Numerical weather forecasts, such as meteorological forecasts of precipitation, are inherently uncertain. These uncertainties depend on model physics as well as initial and boundary conditions. Since precipitation forecasts form the input into hydrological models, the uncertainties of the precipitation forecasts result in uncertainties of flood for...

A hydrological model should represent the hydrological most relevant catchment characteristics. These are heterogeneously distributed within a watershed but often interrelated and subject of a certain spatial organisation. In order to reproduce the natural rainfall-runoff response the reduction of variance of catchment properties as well as the inc...

When flood statistics are based on annual maximum series (AMS), the sample often contains flood peaks, which differ in their genesis. If the ratios among event types change over the range of observations, the extrapolation of a probability distribution function (pdf) can be dominated by a majority of events that belong to a certain flood type. If t...

The utilization of groundwater for irrigation purposes
becomes problematic if groundwater recharge decreases through climate
variability. Nevertheless, the degree of groundwater utilization for
irrigation increases significantly in dry periods, when the amount of green
water is strongly limited. With an increasing gap between water demand and
suppl...

Dieses Buch vermittelt die Grundlagen des Wasserkreislaufs mit seinen räumlichen und zeitlichen Mustern. Dabei werden u.a. der Einfluss der Landnutzung und des Klimas beschrieben, landschaftliche und regionale Besonderheiten erläutert und ein Einblick in die hydrologische Praxis der Bewässerung, der Risikovorsorge und des Flussgebietsmanagements ge...

Flood quantile estimation based on partial duration series (peak over threshold, POT) represents a noteworthy alternative to the classical annual maximum approach since it enlarges the available information spectrum. Here the POT approach is discussed with reference to its benefits in increasing the robustness of flood quantile estimations. The cla...

Model ensembles are possibly the most powerful tool to assess uncertainties in runoff predictions stemming from inadequacies in model structure. But in many applications little knowledge is gained about the specific weaknesses of the individual models. Here we introduce the ensemble range approach (ERA). Compared to other ensemble techniques, ERA i...

Some of the major challenges in modelling rainfall-runoff in urbanized areas are the complex interaction between the sewer system and the overland surface, and the spatial heterogeneity of the urban key features. The former requires the sewer network and the system of surface flow paths to be solved simultaneously. The latter is still an unresolved...

In case of extreme flood events, the superposition of peak discharges of adjoining catchments leads to flood coincidence. Risk-oriented design approaches require the assessing of the plausibility of such scenarios. However, the univariate peak statistics is not sufficient for that purpose. Therefor there is a demand of a multivariate statistical ev...

In regional frequency analysis the homogeneity of a group of multiple
stations is an essential pre-assumption. A standard procedure in hydrology to
evaluate this condition is the test based on the homogeneity measure of Hosking and
Wallis, which applies L-moments. Disadvantages of it are the lack of power when
analysing highly skewed data and the i...

We compare several estimators, which are commonly used in hydrology, for the pa-
rameters of the distribution of flood series, like the Maximum-Likelihood estimator or
L-Moments, with the robust estimators Trimmed L-Moments and Minimum Distances.
Our objective is estimation of the 99%- or 99.9%-quantile of an underlying Gumbel or
Generalized Extrem...

In German speaking countries, specific runoff values (quotients of discharge and belonging catchment areas) are widely used for regionalization. In many cases, a nonlinear regression is applied to describe the relationship between the specific runoff and the size of watersheds. The problem of this approach consists in the multiple use of the area:...

Meteorological forecasts of precipitation are uncertain. This uncertainty depends on model physics, boundary and initial conditions. To consider the unavoidable uncertainties of flood forecasts, resulting from uncertainties of precipitation forecasts, which form the input into hydrological models, ensemble prediction systems are applied. These syst...

Although the consequences of floods are strongly related to their peak discharges, a statistical classification
of flood events that only depends on these peaks may not be sufficient for flood risk assessments. In
many cases, the flood risk depends on a number of event characteristics. In case of an extreme flood, the whole
river basin may be affec...

In his article Willems (Clim Chang 120(4):931-944, 2013) proposed a methodology to analyse extremes in rainfall series. When applying it to artificially generated, non-cyclic random variables we were able to detect cyclic behavior. Therefor we had a closer look on the methodology. Here we discuss our considerations, why this method generates cycles...

In the past the flood design was dominated by safety oriented concepts. A design
flood was chosen with the basic assumption that it defines the limit up to which a flood can be
controlled completely by technical measures. Often peak values with very small probabilities
are used. Thus the risk of an event beyond the design flood seems to be very sma...

Balancing the temporal variability of hydrological conditions in the long- and short-term is often essential for steady socio-economic conditions. However, this equilibrium is very fragile in many cases. Hydrological changes or socio-economic changes may destroy it in a short time. If we extend the bearing capacity of socio-hydrological systems we...

Growing advances in remote sensing technologies together with the widespread availability of Digital terrain models (DTM) have intensified the research into two-dimensional (2D) models. Supported by detailed DTM, 2D models can become very accurate tools yet not without an added cost on the computational effort. Floodplain inundation is characterise...

Partial duration series (peak over threshold) form a considerable alternative to the classical
annual maximum approach since they enlarge the information spectrum. The classical POT
approach is based on a Poisson distribution for the annual number of exceedances although
this is can be questionable in some cases. Therefore two different distributio...

In recent years, the analysis of the impact of structural model inadequacies on simulation uncertainty has gained increased attention in hydrological research. One aspect of structural model inadequacy is the imperfect numerical integration of differential equation systems. This aspect is still neglected in many rainfall runoff and water balance mo...

Since the shift from safety-oriented planning towards risk-based flood management planning, both hydrology/hydraulic research as well as operations research have made remarkable progress. Unfortunately, in the transfer of information between both areas of expertise, valuable spatial information is being lost, which may lead to flawed decision-makin...

In the past the flood design was dominated by safety oriented concepts. A design flood was chosen with the basic assumption that it defines the limit up to which a flood can be controlled completely by technical measures. Often peak values with very small probabilities are used. Thus the risk of an event beyond the design flood seems to be very sma...

Often the evaluation of f lood detention results from a single design event which is considered as adequate. Such approaches reach their limits by observing the flood control efficiency of one or more detention reservoirs in large river basins, because single flood events cannot represent the diversity of potential flood loads in a catchment. The a...

The new Scientific Decade 2013–2022 of IAHS, entitled “Panta Rhei—Everything Flows”, is dedicated to research activities on change in hydrology and society. The purpose of Panta Rhei is to reach an improved interpretation of the processes governing the water cycle by focusing on their changing dynamics in connection with rapidly changing human syst...

A flood is an extreme hydrological event which is characterized by several correlated variables (flood peak, volume and duration). The efficiency of flood reservoirs is strongly affected by the event-specific combination of the two correlated characteristics flood peak and flood volume. As flood events with unusual combinations of these characteris...

The EU Floods Directive requires the assessment of flood risks for different exposure scenarios. These are characterized by low, medium and high probabilities. A quantitative characterization of the flood probabilities of these categories is lacking. A wide consensus exists in Germany to use a flood with a return period of 100 years as a medium-pro...