Enda O'Connell

• Doctor of Philosophy
• Professor at Newcastle University

Polders are low-lying areas located in deltas, surrounded by embankments to prevent flooding (river or tidal floods). They rely on pumping systems to remove water from the inner rivers (artificial rivers inside the polder area) to the outer rivers, especially during storms. Urbanized polders are especially vulnerable to pluvial flooding if the drai...

Precipitation deficits are the main physical drivers of droughts across the globe, and their level of persistence can be characterised by the Hurst coefficient H (0.5<H<1), with high H indicating strong long-term persistence (LTP). Previous analyses of point and gridded annual global precipitation datasets have concluded that LTP in precipitation i...

Hurst’s seminal characterisation of long-term persistence (LTP) in geophysical records more than seven decades ago continues to inspire investigations into the Hurst phenomenon, not just in hydrology and climatology, but in many other scientific fields. Here, we present a new theoretical development based on stochastic Hurst–Kolmogorov (HK) dynamic...

The airflow surrounding any catching-type rain gauge when impacted by wind is deformed by the presence of the gauge body, resulting in the acceleration of wind above the orifice of the gauge, which deflects raindrops and snowflakes away from the collector (the wind-induced undercatch). The method of mounting a gauge with the collector at or below t...

The long-range dependence (LRD) is considered an inherent property of geophysical processes, whose presence increases uncertainty. Here we examine the spatial behaviour of LRD in precipitation by regressing the Hurst parameter estimate of mean annual precipitation instrumental data which span from 1916-2015 and cover a big area of the earth's surfa...

Climate change is viewed as the major threat to the security of water supplies in most parts of the world in the coming decades, and the water resources literature continues to be dominated by impact and risk assessments based on the latest climate projections from General Circulation Models (GCMs). However, the evidence for anthropogenic changes i...

Flooding is a very costly natural hazard in the UK and is expected to increase further under future climate change scenarios. Flood defences are commonly deployed to protect communities and property from flooding, but in recent years flood management policy has looked towards solutions that seek to mitigate flood risk at flood-prone sites through t...

The most widely used device to measure rainfall is the tipping bucket rain gauge (TBR), although there is no standard design. The precision and accuracy of TBR measurements vary, and calibration procedures are dependent upon the organisation or institution operating a network. Consequently, rainfall datasets may be heterogeneous and not easily comp...

Emanating from his remarkable characterization of long-term variability in geophysical records in the early 1950s, Hurst’s scientific legacy to hydrology and other disciplines is explored. A statistical explanation of the so-called ‘Hurst Phenomenon’ did not emerge until 1968 when Mandelbrot and co-authors proposed fractional Gaussian noise based o...

This chapter describes the research activity on risks and extremes at Wallingford. With the agreement of the Steering Committee, the Flood Studies Report (FSR) (NERC, 1975) was published in 1975 in five volumes, containing the hydrological recommendations, the meteorological and flood routing studies and the hydrological data and maps. By the mid 1...

Rainfall measurement has an extensive historical precedent. Attempts have been made to standardise measurement procedures. This has never been successfully achieved. There are many sources of measurement error, some of which are compounded by poor rain gauge siting and a variation in gauge height. By far the worst cause of measurement inaccuracy is...

Due to the perceived threat from climate change, prediction under changing climatic and hydrological conditions has become a dominant theme of hydrological research. Much of this research has been climate model-centric, in which GCM/RCM climate projections have been used to drive hydrological system models to explore potential impacts that should i...

The nature of causal links between land management in rural river catchments and the flood hydrograph is investigated. A catchment can be represented as a mosaic of tiles with different land use, land management, and soils. Over the mosaic, the causal links vary with the physical properties of the land and channel drainage network, and with the man...

Despite many advances in the field of hydroinformatics, the policy and decision-making world is unable to use these highly technical decision support systems (DSSs) because there has been an undue emphasis on the technological aspects. The historical analysis of hydroinformatics concepts and modelling shows that the technical aspects have been inco...

The Système Hydrologique Europeén (SHE) modelling system and physically-based distributed modelling (PBDM) were discussed in Refsgaard et al.'s Système Hydrologique Europeén (SHE): review and perspectives after 30 years development in distributed physically-based hydrological modelling (Hydrology Research 41, pp. 355-377). The opportunity is taken...

The Hurst phenomenon, which reflects long-term fluctuations in geophysical time series, has attracted the attention of the research community for nearly 60 years due to its practical and theoretical importance. Yet a geophysical understanding of the Hurst phenomenon has remained elusive despite mutually conflicting hypotheses of long-term memory an...

Despite many advances in the field of hydroinformatics, the policy and decision-making world is unable to use these highly technical decision support systems (DSSs) because there has been an undue emphasis on the technological aspects. The historical analysis of hydroinformatics concepts and modelling shows that the technical aspects have been inco...

James (Jim) Clement Ignatius Dooge died peacefully at his home in Dublin, Ireland, on 20 August at age 88. His passing has left an unusual sense of loss among the scientific community. Jim was an active member of AGU for almost 60 years. He joined in 1951 and was honored as Robert E. Horton Medal winner (1959), Fellow (1980), Bowie medalist (1986)...

Strategic Approach to Flood Risk Management Under Changing and Uncertain ConditionsHistorical Context: Runoff Generation and Routing in Changing Landscapes and the Evidence for ImpactsStrategic Research FrameworkMultiscale Experimentation in Support of Modelling and PredictionModelling, Predicting Impacts and Vulnerability MappingDiscussion and Con...

Methodologies for determining flood protection investments have traditionally relied on past hydrological records being stationary and therefore statistically representative of future conditions. Due to climate change, it has been suggested that the hypothesis of stationarity for hydrological time series models is no longer tenable, and that nonsta...

While urbanization is widely associated with changes to the runoff generation and flooding regimes of catchments worldwide, the rural landscape has also undergone major changes. Over the past fifty years, much of the European landscape has been transformed as a result of changes in land use and management. The growth in intensive agriculture and as...

It is increasingly recognised internationally that the management of land and water is strongly interdependent, and that integrated management approaches are needed. There is evidence that modern land management practices have caused an increase in flood risk in rural upland areas, so there is the potential to use land management control as a tool...

Since the advent of modern computing platforms in the 1960s and despite scepticisms and uncertainties, modelling systems have become indispensable tools in water resources management. They have been postulated to support the decision-making process and hence the term decision support systems (DSSs) emerged. Hydroinformatics is a recent term compare...

The Middle East and North African (MENA) countries are characterized by rapid population growth, increase in urbanization and scarce water resources. The rapid industrialization and economic growth has brought about a great demand for water supply and sanitation in the region. In the last decades, structural approaches such as building more dams, d...

Vijay K. Gupta was awarded the 2008 Robert E. Horton Medal at the AGU Fall Meeting Honors Ceremony, held 17 December 2008 in San Francisco, Calif. The medal is for ``outstanding contributions to hydrology.''

Middle East and North African (MENA) countries are characterized by water scarcity. Now, it is a common understanding that ethical and cultural factors play an important institutional role towards implementing a sustainable water policy in the water scarce regions. Islam is the dominant religion and hence its ethical principles can be considered to...

Providing a safe and reliable source of drinking water and improved sanitation for urban population are one of the main global challenges of the 21 st century and part of Millennium Development Goals. Iran is trying to achieve these goals and ratified its strategic Long Term Plan for water resources in 2004. Water shortage condition is not just app...

The institutional dimension of water resources management has been neglected and the lack of proper institutional setup has prompted the need for reforms. A water institution can be decomposed into 3 main components: water policy, water law and administration. Christianity, Islam, Judaism, Hinduism and Buddhism and other religions and beliefs mirro...

The potential of technology to help solve many of the world's most pressing problems, ranging from climate change to resource scarcity and poverty, is widely recognised. However, rationally managing and engineering the Earth's systems is a hugely complex task, which extends engineering from its traditional technical domain to dealing with coupled h...

Integrated Water Resources Management (IWRM) Paradigm was introduced some 36 years ago after the creation of the International Water Management Association (IWRA), Braga 2001. IWRM comprises of 4 main areas: land use, river basin, Urban and Coastal Zones. In a recent paradigm shift related to integrated water resources management (IWRM) in the cont...

The error in physically-based rainfall-runoff modelling is broken into components, and these components are assigned to three groups: (1) model structure error, associated with the model’s equations; (2) parameter error, associated with the parameter values used in the equations; and (3) run time error, associated with rainfall and other forcing da...

Drainage basins in many parts of the world are ungauged or poorly gauged, and in some cases existing measurement networks are declining. The problem is compounded by the impacts of human-induced changes to the land surface and climate, occurring at the local, regional and global scales. Predictions of ungauged or poorly gauged basins under these co...

New predictive methodologies are needed to support sustainable catchment management, particularly in poorly gauged or ungauged basins. The CHASM research programme has been established to gain new understanding of the hydrological and ecological functioning of mesoscale catchments (10 2 –10 3 km 2) and of how catchment response changes with scale,...

This article presents a prototype, user-interactive computing system for the operational management of the Kirazdere reservoir in Turkey. The aim is to make best use of the full storage capacity of the reservoir for meeting the contractual water-supply obligations as consistently as possible, having regard to the possible risk of downstream floodin...

A geomorphologic instantaneous unit hydrograph (IUH) consists of two components, one relevant to the geomorphology and the other to the hydraulic aspect describing the movement of a drop of water along a stream. Different formulations of the geomorphologic IUH are reviewed, and a contrast is drawn between the geomorphologic and hydraulic components...

Modeling of the rainfall-runoff process is of both scientific and practical significance. Many of the currently used mathematical models of hydrologic systems were developed a genera­ tion ago. Much of the effort since then has focused on refining these models rather than on developing new models based on improved scientific understanding. In the p...

ESPRIT programme proposal of the development of a prototype of an intelligent knowledge-based system (IKBS) for the management of processess evolving in time, which involve risks and/or uncertainties is addressed.

This chapter focuses upon real-time hydrological forecasting, and the mathematical apparatus necessary to carry out such forecasting. To successfully design real-time forecasting models, one requires an in-depth understanding of both hydrology and statistics. The chapter emphasizes the statistical and systems theory aspects of forecasting since the...

This paper, the second of a two part description of the modelling activities associated with the Bedford Ouse Study, concentrates on the theme of water quality modelling. In the first part of the paper streamflow models of a dynamic-stochastic type were developed and this approach has been extended during the water quality modelling studies. Recurs...

Almragt-This paper, the second of a two part description of the modelling activities associated with the Bedford Ouse Study, concentrates on the theme of water quality modelling. In the first part of the paper streamflow models of a dynamic-stochastic type were developed and this approach has been extended during the water quality modelling studies...

Reservoirs are of necessity always built on the basis of incomplete hydrological information which introduces uncertainty into their design and operation. Since the advent of the electronic digital computer attempts have been made to reduce the uncertainty in hydrological design and reservoir management by the use of synthetic hydrology and simulat...

Hydrologists frequently need to estimate lag 1 correlation ρ1 from rather short observed records of length n. The most commonly used algorithms for estimating ρ1 can give seriously biased estimates if n is small and |ρ1| is large. Small sample bias corrections based on the assumption of a lag 1 Markov generating process are available for ρˆ1, but t...

Methods of modelling the runoff process on the Ray catchment are described. These depend on soil moisture accounting and simple descriptions of the generation of runoff and of routing. It is found possible, with simple models, to account for about 90 per cent of the initial variance of runoff volumes and about 75 per cent of the initial variance of...

An attempt to model the runoff process on the Brosna catchment is described. Different models are compared and it is found possible to account for about 80 per cent of the initial variance of the discharge by very simple models.

The paper deals with stochastic models of daily river flow sequences. It stresses the non-stationary, periodic behaviour and the complex structure of internal dependence of these processes. After a review of empirical and theoretical models proposed in literature, the paper points out the usefulness of conceptual models based on the specific struct...

Il est de plus en plus admis qu'il nous faut pour les projets d'évacuateurs une estimation de la valeur des crues qui ont une durée de retour de l'ordre de 10.000 ans. Comme la distribution des précipitations pour un bassin versant particulier constitue une borne supérieure de la distribution des crues pour ce bassin, cela permet de contrôler l'ext...

La prévision des événements hydrologiques à partir de séries courtes et fragmentaires de données est un problème important, posant de nombreuses questions statistiques. Un modèle stochastique des débits ou d'autres variables hydrologiques, lorsqu'il est étalonné sur des données connues, permet, s'il est suffisamment exact, de simuler à l'aide d'un...

Recent flooding in the UK has raised increasing concerns that changes in modern rural land use/ management (LUM) practices may be having a detrimental effect on flooding downstream. An understanding must therefore be developed of how distributed upstream effects on runoff can affect downstream flooding, as a basis for designing efficient and safe r...

Describes the development of the methodology required for this study, together with the results of its application. The sections are: model evaluation framework; models for evaluation; analysis of inflows to Lake Nasser 1871-1975; the Lake Nasser simulation model; application of model evaluation framework. -K.Clayton

A user manual for the computer programs needed to implement the methodology described in Volume I. Programs cover: simulation model of Lake Nasser; statistical tests; Hurst coefficient tests; model selection criteria; and model selection extended. -K.Clayton

1] During the last decade, there have been increasing concerns over water resource drought in northern England, brought about by the 1995 Yorkshire drought with an estimated 5-month rainfall return period of 200 years. The impacts of climatic change and variability on water resource reliability, resilience, and vulnerability in this region are exam...