Water Resources Studies Research Articles

Anatomy of a catchment: the relation of physical attributes of the Plynlimon catchments to variations in hydrology and water status

Abstract. The Plynlimon headwater catchments in mid-Wales have been a landmark study of water resources in the UK uplands for over 30 years. The main physical features of the catchments have been digitised as the basis for linking new model developments and process understanding. Examples are given of how the main physical attributes are related to land management, hydrology and water quality. These data are also being used to provide insights into catchment processes that may underpin the development of new research. This work is particularly relevant given the need for the assessment of water status under the Water Framework Directive. The paper presents hypothetical management scenarios for the catchments, to show how ecological status may be improved, for example, by selectively restructuring areas of commercial forest. Keywords: Plynlimon, GIS, catchment study, forestry, hydrology, WFD

Single collocation point methods for the advection–diffusion equation

This article is offered to honor Professor George F. Pinder. Its technical contents were motivated by an Eulerian–Lagrangian method that was recently proposed by him and his collaborators. Two one-node-collocation algorithms, which may be used to advance that method are presented. Although they are here discussed for 1-D problems only, one of them has already been generalized to problems in several space variables. Thus, this paper essentially generalizes the above mentioned Eulerian–Lagrangian method of Pinder et al. to problems in several dimensions. Also, the results presented in this paper have a wider interest in water resources studies because they apply to advection diffusive transport processes in general. The methodology used to develop the new algorithms is a unified theory of domain decomposition methods (DDM), recently introduced by the authors and which owes much to George F. Pinder. The results reported in the present paper illustrate, by the way, its application and power.

Groundwater in a national water strategy, 1964–1979

Abstract The Water Resources Board was formed in 1964, an outcome of the Water Resources Act of 1963. Its remit was to advise the Government and the new river authorities on ‘the proper use of water resources in England and Wales’. It made three major regional studies of water resources and, in 1973, advocated a national water strategy. The Water Resources Board was disbanded in 1974 following the reorganization of the water industry under the Water Act of 1973 which created the regional water authorities. In the 1970s, a decline in the rate of population growth together with an economic recession reduced the demand for water and the Board’s proposals were not fully implemented. After 1974 the Central Water Planning Unit continued the Water Resources Board’s role until it too was disbanded in 1979.

Regional Climate Scenarios for use in Nordic Water Resources Studies

According to global climate projections, a substantial global climate change will occur during the next decades, under the assumption of continuous anthropogenic climate forcing. Global models, although fundamental in simulating the response of the climate system to anthropogenic forcing are typically geographically too coarse to well represent many regional or local features. In the Nordic region, climate studies are conducted in each of the Nordic countries to prepare regional climate projections with more detail than in global ones. Results so far indicate larger temperature changes in the Nordic region than in the global mean, regional increases and decreases in net precipitation, longer growing season, shorter snow season etc. These in turn affect runoff, snowpack, groundwater, soil frost and moisture, and thus hydropower production potential, flooding risks etc. Regional climate models do not yet fully incorporate hydrology. Water resources studies are carried out off-line using hydrological models. This requires archived meteorological output from climate models. This paper discusses Nordic regional climate scenarios for use in regional water resources studies. Potential end-users of water resources scenarios are the hydropower industry, dam safety instances and planners of other lasting infrastructure exposed to precipitation, river flows and flooding.

Control and Management Study of Jordan's Water Resources

The paper addresses the main options to reduce the long-term water gap and the specific projects for future pursuit. Water imports from areas outside Jordan by land and/or sea and desalination of seawater using single seashore plants or the intersea project are the main options for supplementing the available conventional water in Jordan. The assessment of the different potential options to meet the future demand considered the technical and economic aspects, the environmental impacts, and the socio-economic and political implications. Seawater desalination seems to be the most suitable development option according to the prevailing conditions and available data.

STAKEHOLDER INVOLVEMENT IN WATER‐RESOURCES PLANNING

ABSTRACTThis paper discusses experiences of consultation and participation in water‐resource planning studies in the Thames catchment. Two different case studies are presented and the challenges which were encountered are discussed. The authors conclude that, whilst the inclusion of stakeholders in the decision‐making process has clear benefits, the answers to questions such as (a) who to involve, (b) when to involve them, and (c) how to present information to them, are not always clear.

Multifractals as a tool to overcome scale problems in hydrology

In hydrology, meteorology, oceanography, climatology and, more generally, in geophysics—all sciences which are involved in water resources management, researches and studies—technological and operational developments come up against a fundamental difficulty which is the extreme variability of geophysical fields. This extreme variability is often associated with natural hazards such as earthquakes, tornados, droughts, or floods and with a very large range of scales. This range extends from millimetres to thousands of kilometres in space, from milliseconds to geological eras in time. The traditional approaches to studying geophysical fields tend to ignore these basic empirical facts by making drastic truncations, that is to say studying one scale independently of the others, transforming partial differential equations into ordinary differential equations, arbitrarily hypothesizing the homogeneity of fields, and performing ad hoc and unjustified parameterizations. Alternative approaches to nonlinear variability are based on a fundamental property of nonlinear equations: scale invariance. In this paper, an attempt is made to give some examples of such scale invariant behaviour of hydrological processes and fields—mainly from empirical evidence. Furthermore, it is shown why and how the multifractal approach, which is still at the developmental stage, is a very promising domain. This approach may provide hydrology with useful concepts that could tomorrow turn into essential tools for water resource management.

Calibration of Landsat thermal data and application to water resource studies

The newest in the Landsat series of satellites was launched April 15, 1999. The imagery collected by Landsat is used for a myriad of applications, from coral reef studies to land management. In order to take advantage of Landsat 7 data, the Enhanced Thematic Mapper+ (ETM+) instrument must be calibrated. This study focuses on the immediate postlaunch calibration verification of the Landsat 7 thermal band (Band 6), specifically so that it can be useful in water resource studies. Two year's worth of thermal calibration results using a combination of underflight data and ground truth show the ETM+ to be extremely stable, though the prelaunch calibration produces an offset of 0.261 W/m 2 sr μm. This paper focuses on the details of the calibration process, including problems faced with ground truth instrumentation. While the technical emphasis in this paper is the calibration of Landsat thermal data, it is presented in the context of the water resource studies for which calibrated thermal data are required. At certain times in the year, water quality in large lakes, particularly the spatial structure of water quality, is driven by temperature of lake waters. During the spring warming, a phenomena called the thermal bar drives the current and sedimentation of large water bodies. A long-term goal of this study is to use thermally driven hydrodynamic models of lake processes to better understand and monitor water quality in large lakes. This paper presents the hydrodynamic model and the relationship between temperature and water quality in the Great Lakes as one example of why high-resolution, well-calibrated data are critical to earth observing.

Editor’s Message Isotope techniques for monitoring groundwater salinization

Steady increase in the salinity of most of the major aquifers being used for water supply in the arid and semi-arid regions of Africa and Asia provides evidence of waterquality deterioration. This salinization is often due to inflow of dense saline water during heavy withdrawals of fresh water from coastal aquifers and/or mobilisation of saline groundwaters by the over-exploitation of inland aquifer systems. Water pollution (salinization) due to extensive irrigation and uUse of fertilisers and other pesticides is also growing. Since there are several sources for the groundwater-quality deterioration, it is necessary to characterise the specific processes involved. Isotope techniques are particularly effective for identifying the sources of salinity and the inflow of fresh groundwater. The fundamental relationships between δ 18 O and δ 2 H and between δ18O and salinity have been used in previous studies to identify different salinization pathways. These include flushing of airborne salts by precipitation or by dissolution of evaporitic minerals from the surface, the soil, or aquifer materials; and the encroachment of seawater, or the induced flow from pockets of connate brine. Although this basic approach is still valid, in the past decade new isotope tools for investigating the dissolved component (such as δ 37 Cl and δ 11 B) have appeared mainly as the results of methodological investigations or in isolated case studies. The International Atomic Energy Agency (IAEA) has a long tradition and wide experience in the use of isotope techniques for water-resources studies and is acting as the international focal point in promoting the practical application of isotope methods on a wider scale. Over the past decades, the Isotope Hydrology Section of the IAEA has monitored more than 40 research contracts and technical cooperative studies in this field, including determination of the origins of groundwater salinization, assessment of groundwater resources in coastal areas and islands, and evaluation of the effect of irrigation activities on groundwater quality (IAEA 1985, 1996, 1998, 2001). In these studies, both naturally occurring stable and radioactive isotopes were used. In 2000, the Agency launched a new initiative aimed at investigating the origins of salinity (salinization processes) and their impacts on coastal fresh-water resources using a multi-isotope approach combining various stable and radioactive isotopes (deuterium, tritium, oxygen18, carbon-14, carbon-13, sulphur-34, boron-11, strontium-87, chlorine-36, and iodine-129. The studies will be conducted within the framework of a Coordinated Research Programme (CRP) entitled, “Origins of salinity and impacts on fresh groundwater resources. Optimisation of isotope techniques.” Several proposals from contract holders in China, Israel, Jordan, Tunisia, Morocco, Korea, and Pakistan were evaluated in terms of how they meet several pre-defined criteria which were found to be the most important for the selection of a “flagship” site where an international team will conduct a study using a multiple-isotope approach.

The United States and the Mekong Project

The United States has historically been a strong supporter of coordinated, international water resources studies and planning in Southeast Asia's Lower Mekong River Basin. Since 1975, however, the United States has not contributed to the Mekong Project. Nonetheless, the United States may benefit in several ways by supporting the Mekong River Commission. This paper describes a rationale for renewed US participation in the Mekong Project and identifies several Mekong River Commission Secretariat programs to which the United States could contribute.

Operational testing of a water balance model for predicting climate change impacts

The ability of water balance models to incorporate month–month or seasonal variations in climate, snowfall and snowmelt, groundwater fluctuations, soil moisture characteristics, and natural climatic variability makes them especially attractive for water resources studies of climatic changes. The use of conceptual models to explore the impact of climate changes has increased in recent years. Because of the success claimed for these studies, it is likely that computer simulation of catchments will increasingly be used by and for water resource managers as an aid to decision-making. There is therefore a need for a generally accepted method for demonstrating a model’s fitness for such use. The simple split-sample test method may be reasonable in the simplest case of the ‘filling-in missing data’ problem but certainly not if the express purpose of the model is to simulate records for conditions different from those corresponding to the calibration record, such as the problem with predicting the effects of climate changes where the data on the changed system are not (and cannot be) available for comparison with the model predictions. Thus, model validation must demonstrate ‘fitness for the said purpose’.In this paper, available model validation methods are reviewed and the hierarchical scheme for systematic testing of hydrological simulation models according to the modelling tasks, proposed by Klemes (1986) (Klemes, V., 1986. Hydrol. Sci. J. 31, 13–24) is discussed in detail and exemplified using the NOPEX water balance model (Xu, C.-Y., Seibert, J., Halldin, S., 1996. J. Hydrol. 180, 211–236) and NOPEX data.

Return Period and Risk of Hydrologic Events. I: Mathematical Formulation

The estimation of return periods of hydrological events and the corresponding risks of failure of hydraulic structures that are associated with such events are important aspects in many water resource studies. For simple hydrologic events such as those related to independent annual floods, both the return period and the risk of failure can be readily calculated. However, no general applicable methods are available for the estimation of return periods, risk of failure, and reliability of service in cases of more complex hydrological events such as those related to dependent annual flows and droughts. In this paper, the definitions commonly employed for return period and risk of failure are reexamined and a general procedure for their estimation are presented, which may be applicable to a wide range of hydrological events related to floods, droughts, minimum flows, aquifer levels, and reservoir levels and outflows. Part II of this paper includes numerical examples and applications.

Modernity and Hybridity: Nature, Regeneracionismo, and the Production of the Spanish Waterscape, 1890–1930

Spain is arguably the European country where the water crisis has become most acute in recent years. The political and ecological importance of water is not, however, only a recent development in Spain. Throughout this century, water politics, economics, culture, and engineering have infused and embodied the myriad tensions and conflicts that drove and still drive Spanish society. And although the significance of water on the Iberian peninsula has attracted considerable scholarly and other attention, the central role of water politics, water culture, and water engineering in shaping Spanish society on the one hand, and the contemporary water geography and ecology of Spain as the product of centuries of socioecological interaction on the other, have remained largely unexplored. The hybrid character of the water landscape, or “waterscape,” comes to the fore in Spain in a clear and unambiguous manner. The socionatural production of Spanish society can be illustrated by excavating the central role of water politics and engineering in Spain's modernization process. In the first part of the paper, I develop a theoretical and methodological perspective that is explicitly critical of traditional approaches in water-resources studies, which tend to separate various aspects of the hydrological cycle into discrete and independent objects of study. My perspective, broadly situated within the political ecology tradition, draws critically from recent work by ecological historians, cultural critics, sociologists of science, critical social theorists, and political economists. My main objective is to bring together what has been severed for too long by insisting that nature and society are deeply intertwined. In the second part of the paper, I excavate the origins of Spain's early-twentieth-century modernization process (1890–1930) as expressed in debates and actions around the hydrological condition. The conceptual framework presented in the first part helps structure a narrative that weaves water through the network of socionatural relations in ways that permit the recasting of modernity as a deeply geographical, although by no means coherent, homogeneous, total, or uncontested project. In sum, I seek to document how the socionatural is historically produced to generate a particular, but inherently dynamic, geographical configuration.

A framework for the study of seasonal snow hydrology and its interannual variability in the alpine regions of the Southwest

A framework is developed to study variations in winter season precipitation and snow processes and spring season runoff in the alpine basins of the southwestern United States. The framework exploits available high‐elevation precipitation and snow water equivalent (SWE) data, and a regional climate model (RegCM) to study two contrasting winter/spring seasons (1994 and 1995). This work examines the influences of large‐scale atmospheric conditions on cold season hydrology in the Southwest, assesses the capability of the regional climate model for simulating snowpack and runoff in two major alpine basins and evaluates methodologies for employing high‐elevation observations on regional spatial scales and seasonal time‐scales. High elevation data and streamflow measurements from the winter/spring of 1995 show relatively wet conditions, larger snow accumulations and more substantial springtime streamflows in the Rocky Mountains and Sierra Nevada than observations from 1994. Analysis of the large scale atmosphere and surface station data during these periods reaffirms that the wintertime quasi‐stationary wave across North America is an important modulator of precipitation, snowpack, and streamflows in the west. The RegCM simulates the large‐scale circulations in these 2 years well. Errors are apparent in the simulated precipitation fields and are greater when comparing modeled and observed snowpack and runoff. While the simulated snowpack/streamflow errors are controlled by precipitation deficiencies in the Rocky Mountain region, in the Sierra Nevada region the errors are determined by elevation and associated temperature errors. Despite an underprediction of snowpack and runoff, the model is able to reproduce the overall patterns of precipitation and snowcover and to some extent the year to year hydrologic variations. Continued time series of the data employed in this study (high‐elevation precipitation and SWE and streamflow measurements) are crucial for seasonal and interannual studies of water resources in the west.

Solving the advection–dispersion equation using the discrete puff particle method

Abstract A flexible, mass-conservative numerical technique for solving the advection–dispersion equation for miscible contaminant transport is presented. The method combines features of puff transport models from air pollution studies with features from the random walk particle method used in water resources studies, providing a deterministic time-marching algorithm which is independent of the grid Peclet number and scales from one to higher dimensions simply. The concentration field is discretised into a number of particles, each of which is treated as a point release which advects and disperses over the time interval. The dispersed puff is itself discretised into a spatial distribution of particles whose masses can be pre-calculated. Concentration within the simulation domain is then calculated from the mass distribution as an average over some small volume. Comparison with analytical solutions for a one-dimensional fixed-duration concentration pulse and for two-dimensional transport in an axisymmetric flow field indicate that the algorithm performs well. For a given level of accuracy the new method has lower computation times than the random walk particle method.

Water Resources in Brazil and the Sustainable Development of the Semi-arid North East

This paper is the result and synthesis of several water resources studies carried out by a group of specialists within the 'ARIDAS Project-A Strategy for the Sustainable Developmentof North East Brazil'. The paper comprises basically: diagnosis of the water resources situation in the North East; analysis of water sustainability, vulnerability to droughts, current water policies, and implications for the future; and guidelines for the setting up of a new water resources policy taking into account the sustainable developmentof the region. Deficient or critical areas were identified in terms of quantity, quality and vulnerability. Patterns of sustainability and vulnerability indexes were suggested, as well as a few general lines of action.

A Study of Water Resources in Bangladesh

A Study of Water Resources in Bangladesh

A Case Study of the Adequacy of GCM Simulations for Input to Regional Climate Change Assessments

Abstract The Sacramento Basin is used as the focus for a case study testing whether general circulation models (GCMS) are capable of simulating the large-scale and synoptic-scale processes important in studies of regional water resources. Output from a variety of GCMs developed at GISS and NCAR were examined, but only results from Community Climate Model (CCM) simulations are presented since they are typical. The stationary waves, jet streams, and storm tracks in the North Pacific-North America region in the CCM simulators show major differences from the observations, both in the mean and in their interannual variations. In addition, although the stationary wave and jet stream patterns associated with individual storms in the basin exhibit robust differences from mean fields in the observations, these differences are not captured in the models. Consequently, the larger-scale fields necessary for driving nested models and impact models for the basin, or for western North America in general, are problematic...

A Study of Water Resources in Asian Humid Region

A Study of Water Resources in Asian Humid Region

Stochastic weather type simulation for regional climate change impact assessment

A stochastic model is developed for the synthesis of daily precipitation by weather type analysis. Daily rainfall at two sites in southern England is related to the Lamb weather types by using conditional probabilities. Time series of circulation patterns and hence rainfall are then generated using a Markov representation of matrices of transition probabilities between weather types. The model reproduces key aspects of the historic rainfall regime at daily, monthly, and annual temporal resolutions. The general validity of the methodology as a means of disaggregating general circulation model predictions into finer spatial scales for water resource studies is discussed. Several limitations are identified of which the subjectivity introduced by the weather type classification system and the nonstationarity of the precipitation characteristics are the most serious.