Issue 1 > Issue 2 > Issue 3 > Issue 4

JRBM Issue 1 (Free download)

Development of a European Flood Forecasting System
By Dr. P. Bates
Download the full paper [in Adobe PDF format]

Recent advances in meteorological forecast skill now enable significantly improved estimates of precipitation quantity, timing and spatial distribution to be made up to 10 days ahead for model scales of 40 km in forecast mode. Here we outline a prototype methodology to downscale these precipitation estimates using regional Numerical Weather Prediction models to spatial scales appropriate to hydrological forecasting and then use these to drive high-resolution scale (1 or 5 km grid scale) water balance and rainfall-runoff models. The aim is to develop a European Flood Forecasting System (EFFS) and determine what flood forecast skill can be achieved for given basins, meteorological events and prediction products. The output from the system is a probabilistic assessment of n-day ahead discharge exceedence risk (where n < 10) for the whole of Europe at 5 km resolution which may then be updated as the forecast lead time reduces. At each stage the discharge estimates can be used to drive detailed (25–100m resolution) hydraulic models to estimate the flood inundation which may potentially occur. Initial results are presented from a prototype version of the system used to perform a hindcast of the January 1995 flooding events in NW-Europe (Rhine, Meuse).
return to top

Hydro-environmental modelling of riverine basins using dynamic rate and partitioned coefficients
By Prof. R. Falconer & Dr. B. Lin
Download the full paper [in Adobe PDF format]

Details are given of the increasing global public concern relating to hydro-environmental issues and examples are cited of some of the water quality and contaminant problems now being considered by river managers on a regular basis. The limitations and restrictions of both physical and numerical hydro-environmental models are discussed and concerns raised about the increasing use being made by non-specialist river engineers and scientists of complex hydroinformatics tools – often with a minimal appreciation of the complex hydrodynamic, bio- and geo-chemical, sediment transport or computational processes involved. General details are given of numerical models used for flow, water quality, sediment transport and heavy metal concentration predictions in river basin systems and particular emphasis is focused on the influence of some master variables on two key hydroenvironmental processes. These processes include the decay of coliform bacteria and the partitioning of heavy metals. Two case studies are then discussed. In the first of these studies the velocity field and faecal coliform levels were predicted for a hypothetical discharge into a freshwater lake, namely Cardiff Bay, U.K., where the effects of dynamic decay rates were found to be significant. In the second study velocity, suspended sediment and heavy metal concentration distributions were predicted along the Mersey Basin, U.K., with dynamic partitioning coefficients being found to give improved agreement between predicted and measured heavy metal fluxes.
return to top

Risk-based floodplain management – A case study from Greece
By Prof. J. Ganoulis
Download the full paper [in Adobe PDF format]

The use of engineering risk analysis and multi-objective decision-making under risk are considered as tools for floodplain management and extreme flood protection. Distinction is made between (a) the catchment or large scale planning and (b) the local or small-scale design of protection measures. After defining the risk of flooding at different scales and specifying the multiple criteria that must be considered when choosing between alternative measures of floodplain protection and management, the methodology used is illustrated in a case study from Greece (Giofyros Basin, Crete Island), where a devastating flash flood occurred on 13th January 1994. Possible remedial structural and non-structural solutions are analysed in order protect the inhabited area and important public buildings from future extreme floods.
return to top

Managing America’s rivers – who is doing it?
By Prof. D. P. Loucks
Download the full paper [in Adobe PDF format]

The US is blessed with abundant water resources in comparison to many other countries, yet it faces problems associated with periodic droughts, floods, an aging infrastructure, threatened riverine and coastal environments and ecosystems, conflicts over multiple uses, and now new issues related to safety and security. A recent water policy forum (AWRA, 2002) of private, non-governmental, and governmental professionals involved in water management throughout the country addressed these challenges. While there were many different opinions on how to meet these challenges, there were no disagreements on the need for national vision and leadership in supporting basin-wide integrated water resources planning and management. Federal and non-federal water and related land development and management practices and projects within river basins need to fit into an integrated plan for the entire basin if indeed these river systems are to be effectively planned and managed as integrated systems. The condition of America’s major river basins in 10, 20 or 50 years depends on how well various economic and environmental interests are managed in an integrated and sustainable way. This paper proposes some approaches for moving toward meeting these goals.
return to top

Resilience strategies for flood risk management in the Netherlands
By R. Vis, Dr. F. Klijn, K.M. de Bruijn & M. van Buuren
Download the full paper [in Adobe PDF format]

A comparison is made between the current flood risk management policy in the Netherlands, which is a resistance strategy aimed at the prevention of flooding along the lower Rhine River by raising the dikes, and two alternative resilience strategies that aim at minimising the consequences of these floods, but at the same time allow some flooding. The alternative strategies rely on detention in compartments and on discharge via “green rivers”. These strategies were evaluated on their financial impacts (costs and flood damage) and on their impacts on economy, ecology and landscape, as well as on flexibility. The tangible effects, such as costs and damage were calculated using mathematical models; experts awarded scores to the intangibles, such as landscape quality and ecology. It is concluded that the initial costs of the resilience strategies are high whereas the gains, a reduction of the flood risk, will only be perceivable in the long term. On the other hand, the resilience strategies are more flexible and offer more opportunities for nature and landscape development.
return to top

Rivers, chars and char dwellers of Bangladesh
By M.H. Sarker, I. Huque and M. Alam
Download the full paper [in Adobe PDF format]

Bangladesh consists mainly of floodplain and deltaic deposits of the three large rivers entering the country – the Brahmaputra, the Ganges and the Meghna Rivers . Average flood discharges of these rivers are within the range of 1,000 to 100,000 m3/s. Islands and bars are very common features in these rivers. In Bangladesh, the vegetated islands within the riverbanks are known as chars. Around one million people live on these chars. Life and livelihood of these char dwellers are mainly governed by the physical dynamics of the rivers and chars. Due to the historical evolution of the Bengal basin, the rivers are very dynamic in nature, which facilitates to study these rivers effectively using satellite imagery. Analysis of satellite images in combination with social surveys provide a holistic impression about the physical and socio-economic environment of the chars of the different rivers. The main rivers of Bangladesh are not in equilibrium. Adjacent floodplain areas are being captured at the rate of hundreds of meters per year. The internal dynamics within the river banks varies from river to river, resulting in variations in the formation and stability of the chars as well as in the extent and duration of the flooding of the chars From the study of temporal series of satellite images, it was found that char areas within the banks are increasing and are expected to increase further in the next decade. Better utilization of the resources of these chars can contribute to improving the lives of char dwellers and also the erosion displaced people.
return to top

Interbasin transfer projects and their implications – A China case study
By Prof. X. Shao, Prof. H. Wang & Prof. Z. Wang
Download the full paper [in Adobe PDF format]

In large countries with sharp temporal and spatial variation in water resources, interbasin water transfer projects seem to be an ultimate solution to ease water shortage and secure a balanced economic development among different regions. However, such projects are prone to problems and controversies, and may challenge the established basin management, legal system and policy making procedure which are taken for granted until such projects are put under consideration. This paper presents a review of interbasin water transfer projects in China and recent developments in the feasibility study of the South-to-North water transfer project involving the Yangtze River and the Yellow River basins. Its impacts on the water law, policy-making procedures, existing basin management method, as well as on the natural environment, are also discussed.
return to top

Use of economic measures for establishing environmental flowin upstream river basins
By Prof. N. Tamai & Dr. N. Shirakawa
Download the full paper [in Adobe PDF format]

Environmental flow is a hot and current issue in water resources management in many countries in the world. In upstream river basins, it introduces a new constraint to hydropower sector. In the implementation stage of environmental flow economic aspects play a key role in river basin management. Economic measures are useful tools in management because they give strong incentive to conventional water users to change their behavior.We can take advantage of economic measures such as levy and subsidy to achieve consensus among all stakeholders in river basin management. A subsidy system for setting environmental flow release from hydropower stations is proposed based on a benefit function of environmental flow formulated in terms of flow rate. Under this subsidy, each hydropower station estimates the possible amount of subsidy to compensate the power production loss by flow release. Consequently, environmental flow is determined by optimum decision procedure by each hydropower station. This paper provides decision support system to water resources management in upstream river basins. Economic impact of management policy is large in some regions but not so much in others.We clarify that regional variation of economic impacts is a function of fraction of hydropower in total electric output, hydrological condition, and size of local economy. The subsidy system developed in this study is able to provide an economic measure to mitigate the inequity.
return to top

JRBM Issue 2

Modelling of dissolved oxygen and biochemical oxygen demand in river water using a detailed and a simplified model
By M. Radwan, P. Willems, A. El-Sadek and J. Berlamont
Download the full paper [in Adobe PDF format]

Different model types are available to model catchment surface water quantity and quality. They vary from detailed physically-based models to simplified conceptual and empirical models. The most appropriate model type for a certain application depends on the project objectives and the data availability. The detailed models are very useful for short-term simulations of representative events. For long-term statistical information and as a management tool they cannot be used. For that purpose more simplified (conceptual or meta) models have to be used. In this study, dissolved oxygen (DO) and biochemical oxygen demand (BOD) dynamics are modelled in a river in Flanders. BOD sources from agricultural leaching and domestic point sources are considered. Based on this input, concentrations of DO and BOD in the river water are modelled in Mike11 (river modelling software from DHIWater & Environment). Advection and dispersion were taken into consideration, together with the most important biological and chemical processes. Model calibration was done on the basis of available measured water quality data. A more simplified model was calibrated to this detailed model, with the objective to yield more easily long-term simulation results which can be used in a statistical analysis. Two aspects of adequacy of model results are highlighted, namely accuracy and model speed. The conceptual simplified model is 1800 times faster than the Mike11 model. Moreover, the two models have almost the same accuracy. The construction of the simplified model is, however, only possible using simulations with the detailed model. The detailed and the simplified model have to be used in a complementary way.
return to top

The October 2000 flooding in Valle d’Aosta (Italy):
Event description and land planning measures for the risk mitigation
By Sara Ratto and Franco Bonetto
Download the full paper [in Adobe PDF format]

On October 13–16th, 2000 heavy rainfalls in the Northwestern Italian Alps caused huge flooding and landslides with significant damages to houses and infrastructures and several life losses. In this paper a description of the main events that affected Valle d’Aosta’s region and the subsequent land planning measures adopted for the risk mitigation are presented. After a first meteorological and hydrological framing, based on the data of the regional monitoring system (that pointed out rainfalls up to 236mm in 24 h also in high-altitude zones, because of the rise of the isotherm 0?C around 3000m above sea level), the main effects of the event (extensive flooding, landslides, soil slips and debris flows) in the regional catchment of the Dora Baltea river are described. Through aerial and direct surveys those effects have been transferred into a thematic cartography within two months from the event, in order to have detailed elements for the technical, administrative and political land planning decisions, and, on this basis, a new regional directive containing detailed measures for the hydro-geological risk mitigation and land safety has been adopted.
return to top

Velocity predictions in compound channels with vegetated floodplains using genetic programming
By E.L. Harris, V. Babovic and R.A. Falconer
Download the full paper [in Adobe PDF format]

Data collection and storage methods have improved vastly over recent years, however the processes of information and knowledge extraction from data have not mirrored this. The application of computer supported scientific knowledge discovery processes to carefully collected observations aims to improve the understanding of the processes that generated or produced these data. In this paper, these new techniques have been applied to the complex and poorly understood phenomena of flow through idealised vegetation. The ability to predict, with improved accuracy, velocities within wetlands and other vegetated areas would be advantageous as these regions are increasingly being recognised for their natural flood alleviation properties. In this study, laboratory data collected in a flume with steady flows over a deep channel with relatively shallow vegetated floodplains were used to induce the formulation of expressions using a data driven discovery technique, namely genetic programming (GP). The objective of the study was not only to gain an understanding of the effect of vegetation on velocity distributions across a channel but moreover to demonstrate an alternative discovery process. The performance of the genetic program is reported for three variations of the GP. The reported results of the experiments were found to be encouraging and further work is detailed.
return to top

What kind of water models are needed for the implementation of the European Water Framework Directive. Examples from France
By Jean-Gabriel Wasson, Marie-Hélène Tusseau-Vuillemin, Vazken Andréassian, Charles Perrin, Jean-Baptiste Faure, Olivier Barreteau, Mathieu Bousquet and Bernard Chastan
Download the full paper [in Adobe PDF format]

The EuropeanWater Framework directive (WFD) promotes an integrated management approach, defines the river basin as the relevant management unit, and sets the objective of good ecological status for all waters in Europe before 2015. Based on research activities underway in France, this paper presents five examples of issues related to water modelling for the implementation of the WFD. The new concept of “good ecological status” calls for a necessary shift from a classical biogeochemical modelling to an ecological modelling, and for new kind of models which can describe the biological response of aquatic ecosystems to physical disturbance. The integrated management approach demands new kind of models, based on a more global approach, adapted to the scale of work and management to be done; this is illustrated with the rainfall-runoff models. In the field of hydraulics, the complexity is addressed through the creation of models, consisting of several modules, which are optimised as a function of the application desired. Finally, the need of tools in the process of allocating water resources among several actors in a river basin, as foreseen in the WFD, may be addressed by the use of multi-agent systems. All these examples show clearly that the hydrosystem complexity, the study of which requiring the use of physical, ecological, social and economic sciences, cannot be solved easily with a unique type of water modelling. Research is still needed to address this complexity, but also to provide in the same time tools and results for water managers.
return to top

The implementation of a flux model for the application of groundwater integrated management
By L. Alberti, S. Ceccon and D. Bianchi
Download the full paper [in Adobe PDF format]

The paper presents a groundwater flux model that covers an area of about 10 km2 of the south-eastern part of the city of Milano (Italy), as a preliminary tool for the application of a new investigation approach. This research study is one of the goals of INCORE (Integrated Concept for Groundwater Remediation), a European funded project. The project aims at providing a cost-efficient technical administrative set of tools for optimised investigation, evaluation and management of contaminated groundwater and land in urban industrial areas. The model represents a local hydrogeological situation of a site that was polluted by hydrocarbon chlorinates and pesticides; it concerns the upper part of the aquifer in Milan, down to 50m of depth, where the considered pollution is located. The mathematical model was implemented with a 3D finite difference program, called MODFLOW (M. McDonald and A. Harbaugh, 1988–1996). The paper reports a short description of the INCORE project and the new Integral Investigation Method, and describes the implementation of a flux model to plan the Integral Investigation based on some Immission Pumping Tests (IPT’s).
return to top

RIWU – A model of regional economic development and industrial water use in the catchment area of the Upper Danube
By Erich Langmantel and Johann Wackerbauer
Download the full paper [in Adobe PDF format]

The regional-economic model RIWU (Regional Industrial Water Use) describes the development of economy, demography and industrial water use in the Upper Danube catchment area at the smallest possible spatial dissolution. It is part of an interdisciplinary research project with the title: “ GLOWA-Danube – integrative techniques, scenarios and strategies regarding global changes of the water cycle”, funded by the Federal Ministry of Education and Research. The overall goal of this project is to develop and validate integration techniques, integrated models, and integrated monitoring procedures for the functional type of a catchment in mountain forelands of the humid latitudes and to implement them in a network-based Decision-Support-System which will be regionally transferable and thus applicable for a wide range of catchments. This Decision-Support-System will enable local authorities to anticipate future water shortages and to avoid conflicts between different groups of water users. The natural resource “water” can be introduced into economic models by two ways: On the one hand, as input to production processes, water is a limiting factor for regional economic development. On the other hand, water use is positively correlated with economic activity and negatively correlated with water prices. As a consequence, there will be interactions between regional economic development, water extraction, water scarcity and water prices. The regional-economic model RIWU currently consists of eight model equations with which seven endogenous variables are forecast. The exogenous variables are foreign sales and the area of land, the latter provisionally assumed to be constant. The calculated industrial water demand and industrial water extraction are depending both on the costs of water extraction and on industrial value added which is again positively correlated with regional exports and negatively correlated with the price of land.
return to top

Regional estimation of synthetic design hydrographs
By Ugo Maione, Paolo Mignosa and Massimo Tomirotti
Download the full paper [in Adobe PDF format]

In the present paper a procedure for the construction of Synthetic Design Hydrographs (SDH) for ungauged sites is proposed, based on the regional estimation of Flood Duration Frequency (FDF) and Peak-Duration (PD) curves. The basic hypothesis is that the reduction ratio between the quantiles of maximum average discharge in given duration and peak discharge is independent of the return period, which in practice occurs for medium-large catchments. Under this assumption the regional estimation of FDF curves reduces to the estimation of peak discharge quantiles and reduction ratio. The procedure has been applied to the Po river in Italy, employing for the calibration the historical flood waves recorded at eight gauging stations along the river. The regional estimates of SDHs have been compared with the local ones obtained at the gauging stations. At two consecutive upstream stations, the comparison reveals and partly rectifies some clear data inconsistencies due to uncertainties in stage-discharge relationships. The proposed model provides an operational tool for hydrologic risk assessment and flood protection planning along the entire course of the Po river. Moreover, the regionalisation procedure is quite simple and its validity is not restricted to the specific case presented in this paper.
return to top

Implementation of the water framework directive – can we use models as a tool in integrated river basin management?
By Jesper Dørge and Jørgen Windolf
Download the full paper [in Adobe PDF format]

The implementation of the Water Framework Directive requires adjustment of the administrative structure for the water management in each of the Member States. Modifications of the procedures for river basin management are also foreseen. Today, river basin management in Denmark is for the most part carried out at regional levels (in 14 counties) and the environmental problems for freshwater systems in Denmark are mainly associated with diffuse pollution sources (primarily originating from agriculture) and pollution with pesticides and other xeno-biotics. Viewed in the context of the Directive river basin models may play an important role for a successful water administration – being tools in the technical solutions for how to achieve “good status” for groundwater and surface waters. In Denmark integrated river basin modelling is used in connection with restoration projects, also empirical models are widely used. The benefits from applying river basin models are manifold. Besides being able to evaluate “good status” for freshwater bodies based on hydrology, land-use, agricultural practices and ecology of individual river stretches (including lakes and wetlands), modelling can also identify solutions for flood/drought problems in combination with defining protection measures for the aquatic environment.
return to top

Delta processes and management strategies in China
By Zhao-Yin Wang, Shixiong Hu, Yongsheng Wu and Xuejun Shao
Download the full paper [in Adobe PDF format]

Most rivers in China carry high sediment loads, and therefore develop deltas. Many cities have consequently developed near river mouths and have become centers of commerce within China. The increasing population pressure poses new problems and the need for new river basin management strategies. This paper discusses such deltaic processes and the corresponding management strategies for theYangtze,Yellow and Haihe River deltas, with these being three typical examples. TheYangtze River carries large amounts of water and sediment into the East China Sea. Deltaic islands and shores develop continuously at the river mouth, leading to bifurcations of the channels. Navigation channel dredging and land creation projects are being implemented in the estuary, with these projects intended to narrow and stabilize the river mouth. The presentYellow River delta has developed over the past 147 years as a consequence of siltation and avulsions of the river channel, flooding and sedimentation. Human activities has also sharply changed the delta processes. Oil fields and a new city with a modern infrastructure have been developed on the newly created land. The river channel within the delta is unstable and avulsions often occur. Stabilization of the river channel is necessary for construction of the oil field infrastructure and residences etc. Moreover, the sediment is being used for land creation. The Haihe River mouth is shrinking due primarily to the reduced runoff and sediment deposition from the sea. Dredging is only a temporary solution to this problem. Double guiding dykes, long enough to cut off the high turbidity belt along the coast, are being examined as the main strategy to control sedimentation of the river mouths. Sediment transported by coastal and oceanic currents is also being used for land creation.
return to top

JRBM Issue 3

A user perspective in Germany: What is expected by agencies and government from radar data?
By THOMAS EINFALT
Download the full paper [in Adobe PDF format]

In the framework of the development of a concept for radar data use in hydrological services, a survey has been performed. The objective of this survey was to find out the practical requirements on radar data from the users’ perspective. Besides a better technical definition of the concept, the responses showed needs in education and training of radar derived information use in hydrology. This survey was extended to non-hydrological use of radar data during a two year project where online radar data were provided for practical applications in hydrology, agriculture and traffic control. The results showed that there is a discrepancy between the actually produced and provided radar data, and their use and usefulness for practical applications. Additional work requirements include radar data quality control and data correction, application oriented radar data processing, early communication between radar data provider and the users on requirements (e.g. compulsory periods of data availability), and training on the differences between observations at traditional rainfall stations and radar observations.
return to top

A stochastic-dynamic modelling of mountain river watersheds of NE Portugal
By NAIM HAIE and EDNA CABECINHA
Download the full paper [in Adobe PDF format]

An integrated methodology has been developed in order to create and validate a stochastic-dynamic model of ecological integrity. It is based on a series of field datasets of the prevailing biological and environmental variables. The determination of the parameters to be included in the model resulted from a previous conventional multivariate statistical treatment of all collected information. STELLA 5.0® software has been used to develop the simulation models. In order to evaluate the ecological state of the studied ecosystems, multimetric indexes were used. They are ecologically relevant and sensitive to environmental stress agents. Composition, richness, abundance and trophic metrics of benthic macroinvertebrate communities were selected, hence enhancing the importance of pollution control and monitoring in aquatic ecosystems based on ecological integrity indicators. The samples of aquatic macroinvertebrate and the environmental and physico-chemical data were collected from three sub-basins of the rivers of Northeast Portugal. After applying the model to these watersheds, the obtained results are encouraging. A statistically confirmed validation was performed and they seem to demonstrate the model’s reliability. It also predicted reasonably well (statistically significant) the degradations noticed some 10 years later.
return to top

Comparison of management scenarii in a regional groundwater system
By EMANUELA COLOMBO, MARIA LAURA DEANGELIS, ELENA DE BORTOLI and MARIA GIOVANNA TANDA
Download the full paper [in Adobe PDF format]

The groundwater system in the Milan area represents the main water supply for civil and industrial uses. Since the 1950s its natural equilibrium has been conditioned by notable water table fluctuations; in particular during the last decade a remarkable rise in the groundwater level has led to a real state of emergency. Many buildings and subsurface structures were constructed in the 1970s, and they were not designed to coexist with groundwater: at present the foundation and the underground structures of many important constructions (hospitals, parking, subways) are under the water table affecting their durability and security. A complete understanding of the dynamics of the aquifer system is the first step to manage the emergency and to plan opportune interventions. To achieve this purpose, a 3D finite element model is developed for an area bounded by the rivers Po, Ticino, Adda and the pre-Alps. A reliable model of this groundwater system requires current and historical data on a number of key parameters: geology (deep and surface), topography, surface water rivers and channels and their hydraulic characteristics, groundwater levels, recharge from rainfall, pumping from aquifer for civil and industrial uses. The numerical scheme is applied in both the saturated and in the unsaturated zone. The numerical model is calibrated in both steady and unsteady state flow. Different scenarios are performed to simulate the response of groundwater system to various stresses: an increasing of water pumping in the city of Milan, a particularly rainy season, the reopening or the obstruction of spring lines located in South Milan. The results of the model can be a useful tool to optimize intervention, thereby reducing costs of management.
return to top

Assessing the flooding susceptibility of river catchments to extreme rainfall in the United Kingdom
By C.G. COLLIER and N.I. FOX
Download the full paper [in Adobe PDF format]

The recognition of the possibility of extreme flooding remains a major challenge for hydrometeorologists. In this paper a scoring system for river catchments is described which aims to provide an indication of extreme flood potential. By using the scoring system that identifies the contributions to a flood event from a variety of components it is possible to update and comprehend the likelihood of extreme flooding. The scheme is tested using published data of the consequences of extreme storms in England and Wales. The methodology is capable of formalising intelligence tables often developed by flood forecasting and warning teams in the UK Environment Agency using their local knowledge, but on an ad hoc basis. Such a scoring scheme can be used as a decision support tool by practitioners, both in the UK and elsewhere, if adapted to conditions in other areas.
return to top

Bio-ecological drainage system (BIOECODS) for water quantity and quality control
By NOR AZAZI ZAKARIA, AMINUDDIN AB GHANI, ROZI ABDULLAH, LARIYAH MOHD. SIDEK and ANITA AINAN
Download the full paper [in Adobe PDF format]

Land use change in urbanizing watersheds can have a significant impact on hydrologic and hydraulic process as well a degradation of water quality on receiving waters. The Bio-Ecological Drainage System (BIOECODS) consists of elements of storage, flow retarding and infiltration engineering. Swales, dry ponds, detention ponds and wetland are the main components of BIOECODS that function as flow attenuation and water quality treatment devices. The BIOECODS is a pilot project that meets the requirements of the Stormwater Management Manual for Malaysia and has been constructed at the Engineering Campus of the University Science Malaysia, Nibong Tebal, Penang. BIOECODS represents an alternative to the traditional hard engineering-based drainage system to manage stormwater quantity and quality for urban areas. This article discusses how the BIOECODS could be implemented to control stormwater quantity from an urbanized area and reduce the water quality impact on the receiving water.
return to top

Hydrological roles of the Cambodian floodplain of the Mekong River
By HIDETO FUJII, HENRIK GARSDAL, PETER WARD, MASAKI ISHII, KANEHIRO MORISHITA and THOMAS BOIVIN
Download the full paper [in Adobe PDF format]

The purpose of this study was to assess the hydrological roles of the Cambodian floodplain of the Mekong River, from Kompong Cham as far south as the Vietnam border. An intensive observation of water levels at 20 locations, discharge measurements by ADP and ADCP in the main/floodplain channels and analysis of satellite images (RADARSAT) to estimate inundated area and storage volume, were carried out during the flood and post flood season in 2002.Ahydro-hydraulic modelwas set up for the entire study area to establish a tool for assistance in understanding the dynamics of recurrent floods as well as the hydrological roles of the floodplain in Cambodia. The model system used was MIKE11, a generalized one-dimensional model system for rivers and estuaries. The hydraulic modeling work enabled us to assess the hydrological roles of the study area. The flood reduction amount in the peak flood season and river flow augmentation in the dry season were determined as part of the study. The main findings are of importance to floodplain management, as future construction for example for improved road levees and higher agricultural dykes, may reduce the benefits presently derived from flows over the floodplains. The work was carried out under the MRC (Mekong River Commission) Project named Consolidation of hydro-meteorological data and multi-functional hydrological roles of Tonle Sap Lake and its vicinities.
return to top

Conflict and co-operation in international freshwater management: a global review
By ERIK MOSTERT
Download the full paper [in Adobe PDF format]

In the past decades much has been written about international freshwater management. Many writers have predicted that thewars in the 21st century will be over water. More recently, the idea that water can act as a catalyst for peace has gained currency. This article reviews developments in international freshwater management, based on 35 case studies. Many international agreements have been concluded and many river basin commissions have been established, despite conflicts of interests. The most common and most effective strategy to reach agreement has been the desire to develop or maintain good relations. Moreover, the cases show that international freshwater management should involve local governments, NGOs and individual water users if it is to be effective. The article concludes that the old water management paradigm – national water resources development – is gradually being replaced by a new paradigm: integrated river basin management across all levels, national, international and subnational.
return to top

JRBM Issue 4

Developing habitat suitability criteria for water management: a case study
By Lafayette d. Luz and Daniel P. Loucks
Download the full paper [in Adobe PDF format]

A method for assessing the relative quality of a wetland as habitat for fish based on hydrological factors is described. Its three major steps include: (a) simulating the hydrologic behavior based on some water management policy; (b) computing habitat suitability indexes time series derived from the values of the simulated hydrologic variables; and (c) assessing system performance based on those suitability indexes values. The method was applied to a coastal wetland of Lake Ontario in the US. Sequences of daily water levels and water temperature in the wetland were generated considering alternative watershed land use practices and Lake Ontario water level management policies. These variables were converted to habitat suitability time series for a bioindicator, the Northern Pike (Esox lucius), focusing on its early life cycles that take place in the wetland. The overall habitat suitability performance was analyzed in terms of various reliability, resilience, and vulnerability performance indices derived from those habitat suitability time series. Results show that at least for the early life cycles of the chosen bioindicator a less variable water level regime that comes mainly from Lake Ontario regulation is more beneficial than from one that results from natural variation. A more variable regime, however, seems to favour the marsh or the wetland plant habitat upon which the fish are dependent, based on an analysis not presented in this paper. In this case study the larger bordering lake had a much greater influence on wetland water levels and temperatures than did the upstream watershed. This particular study is just part of an overall evaluation of lake level management policies based on economic and social as well as ecological criteria currently underway by a joint Canadian-United States commission. Analyses of this type based on multiple species indicators and on a broader set of environmental factors would provide a way to judge the relative ecological impacts associated with diverse lake level regulation policies.
return to top

Pseudo two-dimensional simulations of internal and boundary fluxes in stratified lakes and reservoirs
By P.S. Yeates and J. Imberger
Download the full paper [in Adobe PDF format]

New mixing algorithms to model the vertical mixing processes in stratified lakes have been developed for the Dynamic Reservoir Simulations Model, DYRESM, and have been validated using five lakes of different size, shape and wind forcing characteristics. An analysis of temperature profiles from Lake Kinneret, Canning Reservoir and Mundaring Reservoir, were used to develop a strong inverse relationship between the Lake number and lakewide average vertical eddy diffusion coefficient. Analysis of microstructure data collected in Lake Kinneret using the portable flux profiler suggests that the development of a turbulent benthic boundary layer (BBL) accounts for a large proportion of the lake-wide average vertical flux. A pseudo two-dimensional model with explicit BBL and internal fluxes was developed based on the Lake Kinneret field observations and similar investigations in the literature. A sensitivity analysis revealed that improvements in the ability of DYRESM to model the diverse range of lakes considered without user-calibration was attributable to a wind-sheltering algorithm and a process-based description of BBL and internal fluxes.
return to top

Water availability: a regional water quality problem
By Dale Watson, Colin Arrowsmith and Rob Goudey
Download the full paper [in Adobe PDF format]

The limits to water availability are set, not only by the quantity of water in storages or streams but, more fundamentally, by acceptable levels of environmental health. An interpretation of water quality as inclusive of biological quality infers that environmental health and water quality are interdependent. Consequently, to make effective judgements of water availability managers of water resources need information that presents environmental condition in its regional context. This paper presents the results of research that explores the use of stream turbidity as an indicator of environmental condition, identifies a regional statistical model, and constructs a method to display the distribution of model predictions over a large region of south-eastern Australia. The practical advantage of this approach is that it provides managers with the ability to identify sites that differ significantly from modelled water quality and flag them for further investigation. The major project outputs are a map of regional catchments showing standardised residuals and a raster representation of the state of Victoria in which cell values indicate predicted stream turbidity. Important to this project was the novel use of Geographic Information System technology to process national and regional scale digital data sets using tools developed for catchment scale hydrological models.
return to top

Research Issues on Warning Lead-time and Synergy in Flood Mitigation Measures
By Rahman Khatibi, Ry Stokes, Fola Ogunyoye, Inger Solheim and, Dave Jack
Download the full paper [in Adobe PDF format]

The recognition of the synergy in integrated flood-risk management measures can render further benefits and contribute towards sustainable development. These measures include flood forecasting and warning (FF&W), temporary/demountable measures and insurance, which are linked through lead-time invoking an inherent synergy among them. International experience shows that in many cases FF&W is unjustifiably treated as a discrete measure overlooking inherent synergies. This is inevitably the case when the values of lead-time are short or the degree of confidence in forecast results is unknown. This paper informs on current research activities aiming to improve lead-time through the application of technological innovations. These include the feasibility of integrating meteorological, hydrological and hydraulic forecasting capabilities and decision-making onto one computer platform to manage the full lifecycle of real-time information on flood warning. These projects are part of the fifth European Framework Programme of research projects. The emerging capability would be particularly useful for British catchments, where there is a perception that lead-times are often low. This paper discusses the role of lead-time in maximising the synergy, arguing that the translation of this synergy into benefits is a matter of policy. With an effective policy, the potential benefits can contribute to sustainability of flood risk management measures else; risks can be escalated owing to increased short-term financial opportunities through developments.
return to top

A Conceptual Framework for Identifying the Need and Role of Models in the Implementation of the Water Framework Directive
By Seppo Rekolainen, Juha Kämäri, Marjukka Hiltunen and Tuomo M. Saloranta
Download the full paper [in Adobe PDF format]

The new EuropeanWater Framework Directive (WFD) aims at improving water quality using an integrated approach to implement necessary societal and technical measures. Successful implementation of the WFD requires appropriate mathematical models and other tools to manage different phases of the planning procedure and to support decision making in various steps of the implementation process. Design, development, testing and use of these tools call for the development of a conceptual framework, which provides a basis to assure that proper tools will be available and selected for defined purposes. We developed the well-known DPSIR framework to fit better to the WFD implementation process, and to this framework we identified which types of models are needed in different consecutive steps of the process. The framework, which we call the DPCER framework and which links to different model types, (i) is dynamic, (ii) indicates cause-consequence relationships, (iii) integrates human and natural science, and (iv) is policy relevant. Its purpose is to bring the potential model applications into a wider perspective and lay a foundations for the selection of models and other tools within the identified three different phases of WFD implementation.
return to top