Water Resources Infrastructure Research Articles

Determination of optimized sediment rating equation and its relationship with physical characteristics of watershed in semiarid regions: A case study of Pol-Doab watershed, Iran

Managers always consider the precise estimation of sediments in watersheds due to various conditions, such assoil and water resources management, construction, infrastructure and economical and social issues. In this condition,an optimized determination of sediment rating equation (typical method until now for sediment yield estimation) isessential to investigate sediment yield in rivers. In this study, the best sediment rating equation was determined forfour hydrometric stations of Pol-Doab watershed in Markazi province using sediment rating curves types (singlelinear,multi-linear, mean loads) together with bias correction factors (FAO, Quasi-Maximum Likelihood Estimator[QMLE], Smearing, Minimum Variance Unbiased Estimator [MVUE] and β). The results showed that the optimizedequation in stations is the mean loads (MVUE), which can used for prediction of sediment yield in annual scale.Moreover, FAO factor is more accurate for the estimation of sediment yield in high variability conditions formonthly, weekly and daily scales. According to the obtained results, accurate representation of variability intensity ofsediment yield is associated with the rating curves types, since the monthly rating curve is more accurate. Also, theresults indicated that the watershed average slope has direct relation with b coefficient of rating equation, and whenusing this parameter, the rate of sediment yield can be determined for month, season and hydrological periods. Basedon the obtained results, with increase in the watershed average slope, the slope of suspended sediment concentration(SSC) equation is also increased.

Quantifying the uncertainties of climate change effects on the storage-yield and performance characteristics of the Pong multi-purpose reservoir, India

Abstract. Climate change is predicted to affect water resources infrastructure due to its effect on rainfall, temperature and evapotranspiration. However, there are huge uncertainties on both the magnitude and direction of these effects. The Pong reservoir on the Beas River in northern India serves irrigation and hydropower needs. The hydrology of the catchment is highly influenced by Himalayan seasonal snow and glaciers, and Monsoon rainfall; the changing pattern of the latter and the predicted disappearance of the former will have profound effects on the performance of the reservoir. This study employed a Monte-Carlo simulation approach to characterise the uncertainties in the future storage requirements and performance of the reservoir. Using a calibrated rainfall-runoff (R-R) model, the baseline runoff scenario was first simulated. The R-R inputs (rainfall and temperature) were then perturbed using plausible delta-changes to produce simulated climate change runoff scenarios. Stochastic models of the runoff were developed and used to generate ensembles of both the current and climate-change perturbed future scenarios. The resulting runoff ensembles were used to simulate the behaviour of the reservoir and determine "populations" of reservoir storage capacity and performance characteristics. Comparing these parameters between the current and the perturbed provided the population of climate change effects which was then analysed to determine the uncertainties. The results show that contrary to the usual practice of using single records, there is wide variability in the assessed impacts. This variability or uncertainty will, no doubt, complicate the development of climate change adaptation measures; however, knowledge of its sheer magnitude as demonstrated in this study will help in the formulation of appropriate policy and technical interventions for sustaining and possibly enhancing water security for irrigation and other uses served by Pong reservoir.

The question of Sudan: a hydro-economic optimization model for the Sudanese Blue Nile

Abstract. The effects of development and the uncertainty of a changing climate in eastern Africa pose myriad challenges for water managers along the Blue Nile. Sudan's large irrigation potential, hydroelectric dams, and prime location within the basin mean that Sudan's water management decisions will have great social, economic and political implications for the region. At the same time, Sudan's water use options are constrained by tradeoffs between upstream irrigation developments and downstream hydropower facilities as well as by the country's commitments under existing or future transboundary water sharing agreements. Here, we present a model that can be applied to evaluate optimal allocation of surface water resources to irrigation and hydropower in the Sudanese portion of the Blue Nile. Hydrologic inputs are combined with agronomic and economic inputs to formulate an optimization model within the General Algebraic Modeling System (GAMS). A sensitivity analysis is performed by testing model response to a range of economic conditions and to changes in the volume and timing of hydrologic flows. Results indicate that changing hydroclimate inputs have the capacity to greatly influence the productivity of Sudan's water resource infrastructure. Results also show that the economically optimal volume of water consumption, and thus the importance of existing treaty constraints, is sensitive to the perceived value of agriculture relative to electricity as well as to changing hydrological conditions.

Quantifying coastal system resilience for the US Army Corps of Engineers

The US Army Corps of Engineers (USACE) is responsible for the management of the Nation’s water resource infrastructure and is presently challenged to continue the safe operation and management of that aging infrastructure. These challenges span from changes in climate patterns to increased environmental concerns, greater coastal population densities and associated infrastructure, and limited budgets. One way to mitigate these issues is the concept of resilience. In 2013, the Coastal Engineering Research Board (CERB) began to define resilience and understand its relation to coastal water infrastructure needs. This work was a step forward in facilitating the USACE’s integration of resilience into coastal engineering assessment and project design. The CERB has defined resilience using the four concepts of “prepare,” “resist,” “recover,” and “adapt.” These four concepts are utilized in a system-wide approach that encompasses not only water resource engineered infrastructure (that the USACE builds and manages), but also considers community and ecological infrastructure. Using this framework and literature from previous federal and academic studies, three methods were developed that incorporate different levels of expert and data-driven assessment. Two of these methods, herein named Tier 1 and Tier 3, were tested in a pilot study in Jamaica Bay, NY. Building off of the results from Jamaica Bay, Tier 1 is being refined and Tier 2 is in development.

Selection of the Best Inland Waterway Structure: A Multicriteria Decision Analysis Approach

This study explains the role and effectiveness of Multicriteria Decision Analysis (MCDA) approaches for decision support to rank the best option(s) to reconstruct and rehabilitate the inland waterway structure by demonstrating a case study of River Ilmenau in Germany. Considering the involvement of several stakeholders and community with the status and functionality of the Ilmenau river, this paper also considers the importance of stakeholder participation in the decision making process by an intensive stakeholder interview. A total of 27 criteria were selected that represent a wide range of environmental and socio-economic aspects of the Ilmenau River and the activities related to this river. The ranking of the alternatives were performed by combining AHP (Analytical Hierarchy Process) with PROMETHEE (Preference Ranking Organisation METHod for Enrichment Evaluations) to achieve a rigorous solution of the objective. 23 stakeholders such as decision-makers, experts, and researchers from environmental, administrative, recreational, and socio-economical fields were interviewed to determine the criteria to be weighed. The stakeholders’ opinions showed ecological continuity is one of the most important criteria to be considered. They also gave significant importance to nature protection laws and directives. Among the socio-economic criteria, flood protection was the most important one. Removal of weirs and installation of ground ramps was suggested to be the best option to consider for further investigation and implementation. This study clearly demonstrates the importance of stakeholder and community participation to decision-making process and contributes new information, especially stakeholders’ attitude towards decision making for water resources infrastructure selection.

Note from the Editor-in-Chief

The escalation of tensions between Ethiopia and Egypt over the construction of the Grand Renaissance is at least partly based on a misunderstanding of the nature of the risks this dam poses to Egypt. There is a two-part, win–win deal that can defuse tensions between Egypt and Ethiopia. First, Ethiopia needs to agree with Egypt and Sudan on rules for filling the Grand Renaissance Dam (GRD) reservoir and on operating rules during periods of drought. Second, Egypt needs to acknowledge that Ethiopia has a right to develop its water resources infrastructure for the benefit of its people based on the principle of equitable use, and agree not to block the power trade agreements that Ethiopia needs with Sudan to make the GRD financially viable. Sudan has a big stake in Egyptian–Ethiopian reconciliation over the use of the Nile. Although Sudan’s agricultural and hydropower interests now align with those of Ethiopia, there does not seem to be a formal agreement between Ethiopia and Sudan for the sale of hydropower from the GRD. Because the economic feasibility of the GRD and other Ethiopian hydropower projects will depend on such agreements, Sudan has leverage with both Ethiopia and Egypt to encourage this win–win deal.

Assessment of Potential Dam Sites in the Kabul River Basin Using GIS

The research focuses on Kabul River Basin (KRB) water resources infrastructure, management and development as there are many dams already in the basin and many dams are planned and are being studied with multi-purposes objectives such as power generation, irrigation and providing water to industry and domestics. KB has been centralized all water resources related information in an integrated relational geo-database this KB is centralized repository for information river basin management with the main objectives of optimizing information collection, retrieval and organization. In addition, in this paper information and characteristics of the KRB has been presented such as drainage network or hydrology, irrigation, population, climate and surface pattern other necessary features of the basin by the use of GIS in order to invest and implement infrastracture projects. The first step in doing any kind of hydrologic modeling involves delineating streams and watersheds, and getting some basic watershed properties such as area, slope, flow length, stream network density, etc. Traditionally this was (and still is) being done manually by using topographic/contour maps. With the availability of Digital Elevation Models (DEM) and GIS tools, watershed properties can be extracted by using automated procedures. The processing of DEM to delineate watersheds is referred to as terrain pre-processing. Besides that, it produced the necessary thematic maps, base maps and other detailed maps for illustrating of basin characteristics and features GIS Based.

Assessing competing policies at Ubonratana reservoir, Thailand

As the main water resources infrastructure in the region, the Ubonratana reservoir has played and continues to play a significant role in the socio-economic well-being of north-eastern Thailand. For such a multi-purpose system serving flood protection and various water demand needs, it is important that the reservoir is effectively operated to ensure that the overall performance of the system is enhanced. Consequently, this study has evaluated the performance of the Ubonratana reservoir with four competing operating policies, namely: (a) the pre-2002 policy (P1); (b) a post-2002 policy, following the catastrophic flood of 2002 (P2); (c) a policy derived in the current study to address the limitations of P2 in relation to water shortages (P3); and (d) the standard operating policy, SOP (P4). The simulation analyses were implemented using a water evaluation and planning system model of the reservoir meeting domestic (first priority), industrial (second priority), irrigation (third priority) and in-stream (fourth priority) needs. The performance was summarised in terms of reliability, vulnerability, resilience and sustainability. The results showed that overall, P4 was the best, followed by P3, P1 and P2 in that order. This is a useful demonstration of how rule curves can successfully guide the operation of multi-purpose reservoir systems.

Flow regime change in an endorheic basin in southern Ethiopia

Abstract. Endorheic basins, often found in semi-arid and arid climates, are particularly sensitive to variation in fluxes such as precipitation, evaporation and runoff, resulting in variability of river flows as well as of water levels in end-point lakes that are often present. In this paper we apply the indicators of hydrological alteration (IHA) to characterise change to the natural flow regime of the Omo–Ghibe Basin in southern Ethiopia. Little water resource infrastructure has been developed in the basin to date, and it is considered pristine. The basin is endorheic and is the main source of flow to Lake Turkana in the East African Rift Valley. The water level in Lake Turkana shows significant fluctuation, but increase of its level can be observed over the past 20 years. The reasons are currently not well understood. Of the five groups of hydrological characteristics in the IHA (magnitude, timing, duration, frequency and variability), only those related to magnitude were found to show significant trends, with the main trend being the increase of flow during the dry season. This trend was not reflected in climatological drivers such as rainfall, evaporation and temperature (which shows a positive trend), but rather is attributed to the substantial changes in land use and land cover in the basin. The change in the basin hydrology is apparent mainly in the more humid part of the basin. The significant shift from forest and woodland to grassland and cropland results in a decrease of actual evaporation and subsequent increase in (dry season) runoff. The long-term trend of the increasing levels in Lake Turkana are related to these trends in dry season flows, while shorter-term fluctuations of the lake levels are attributed primarily to anomalies in consecutive wet and dry season rainfall.

The Grand Renaissance Dam and prospects for cooperation on the Eastern Nile

The escalation of tensions between Ethiopia and Egypt over the construction of the Grand Renaissance is at least partly based on a misunderstanding of the nature of the risks this dam poses to Egypt. There is a two-part, win–win deal that can defuse tensions between Egypt and Ethiopia. First, Ethiopia needs to agree with Egypt and Sudan on rules for filling the Grand Renaissance Dam (GRD) reservoir and on operating rules during periods of drought. Second, Egypt needs to acknowledge that Ethiopia has a right to develop its water resources infrastructure for the benefit of its people based on the principle of equitable use, and agree not to block the power trade agreements that Ethiopia needs with Sudan to make the GRD financially viable. Sudan has a big stake in Egyptian–Ethiopian reconciliation over the use of the Nile. Although Sudan's agricultural and hydropower interests now align with those of Ethiopia, there does not seem to be a formal agreement between Ethiopia and Sudan for the sale of hydropower from the GRD. Because the economic feasibility of the GRD and other Ethiopian hydropower projects will depend on such agreements, Sudan has leverage with both Ethiopia and Egypt to encourage this win–win deal.

Water resources planning under climate change: Assessing the robustness of real options for the Blue Nile

AbstractThis article presents a methodology for planning new water resources infrastructure investments and operating strategies in a world of climate change uncertainty. It combines a real options (e.g., options to defer, expand, contract, abandon, switch use, or otherwise alter a capital investment) approach with principles drawn from robust decision‐making (RDM). RDM comprises a class of methods that are used to identify investment strategies that perform relatively well, compared to the alternatives, across a wide range of plausible future scenarios. Our proposed framework relies on a simulation model that includes linkages between climate change and system hydrology, combined with sensitivity analyses that explore how economic outcomes of investments in new dams vary with forecasts of changing runoff and other uncertainties. To demonstrate the framework, we consider the case of new multipurpose dams along the Blue Nile in Ethiopia. We model flexibility in design and operating decisions—the selection, sizing, and sequencing of new dams, and reservoir operating rules. Results show that there is no single investment plan that performs best across a range of plausible future runoff conditions. The decision‐analytic framework is then used to identify dam configurations that are both robust to poor outcomes and sufficiently flexible to capture high upside benefits if favorable future climate and hydrological conditions should arise. The approach could be extended to explore design and operating features of development and adaptation projects other than dams.

How well do general circulation models represent low‐frequency rainfall variability?

AbstractGeneral circulation models (GCMs) provide reliable simulations of global‐ and continental‐scale atmospheric variables, yet have limited skill in simulating variables important for water resource management at regional to catchment scales. GCM simulations suffer from a range of uncertainties leading to transient (changing over time) and systemic (consistent over time) biases in the output when compared to observed records. An important GCM bias in managing water resources infrastructure is the underrepresentation of low‐frequency variability a characteristic central to the simulation of floods and droughts. This study presents a performance metric, the aggregated persistence score (APS), which is used to assess the reliability of GCMs in simulating low‐frequency rainfall variability. The APS identifies regions where GCMs poorly represent the amount of variability seen in the observed precipitation. This study calculated the APS at monthly aggregations for GCM precipitation as well as GCM precipitation that was bias‐corrected to better represent low‐frequency variability. It was found that there were (1) large spatial variations in the skill of GCMs to capture observed rainfall persistence, (2) widespread undersimulation of rainfall persistence characteristics in GCMs, and (3) substantial improvement in rainfall persistence after applying bias correction.

Waterway Performance Monitoring with Automatic Identification System Data

Fiscal constraints at the federal level drive the need for more robust and objective performance evaluation methodologies for use by the U.S. Army Corps of Engineers as it carries out its civil works mission in support of the nation's water resources infrastructure. One specific area of need concerns functional performance evaluation of dredged navigation channels at the local level as well as performance evaluation of systems of navigation projects. The nationwide automatic identification system (NAIS) for vessels that operate in coastal waters was instituted after the terrorist attacks of September 2001 and is maintained by the U.S. Coast Guard. The system constitutes an enabling technology to provide the data required for quantitative performance assessments of corps-maintained navigation infrastructure. In this paper, several applications are presented of archival NAIS data toward waterway performance evaluation. An assessment and comparison also are presented of several deep-draft coastal ports with respect to the sensitivity of vessel transit timing to tidal elevations. The NAIS data archive is applied toward a point-to-point transit time monitoring strategy at the local and regional levels. The corps confronts an uncertain fiscal outlook and constrained budgets for annual operations and maintenance activities. These metrics, as well as other potential applications of archival NAIS data, can play a valuable role in the provision of objective, quantitative assessments of waterway performance.

More than the Fish: Environmental Flows for Good Policy and Governance, Poverty Alleviation and Climate Adaptation

Environmental flows continue to shift conceptually from a utilitarian means of protecting ‘environmental’ needs – often equated with specific fish species of economic and/or conservation value – within the water resources planning and management cycle to a process underpinning the adaptive, sustainable management of social-ecological aquatic systems for multiple benefits and at multiple scales. We explore some of the ways in which environmental flows are clearly transitioning from a discipline designed mainly to conserve aquatic species, through improved site-level water resources infrastructure operations, to a more sophisticated vehicle for achieving the ever challenging goals for sustainable water management and human well-being. These goals are achieved through good governance and policy, and by setting targets for socioeconomic development and climate-resilient resource management. As these dimensions of the policy and practice evolve, the need grows to engage with and draw upon the expertise of a broader community of stakeholders, from the public and private sectors, the social sciences and civil society.

Effects of Marine Overwash for Atoll Aquifers: Environmental and Human Factors

Inundation of atoll islands by marine overwash is a serious threat to fresh groundwater, which can be a critical emergency water resource after artificial storage or other water resource infrastructure has been exhausted or destroyed. In contrast to drought, which slowly exhausts water supplies and often can be forecasted in time, overwash can occur with little warning and can ruin both rain catchment storage and groundwater reserves. In this study, a SUTRA-based model is applied to estimate how groundwater contamination by overwash and subsequent recovery of fresh groundwater are influenced by geologic factors (aquifer hydraulic conductivity, dispersivity, and the presence or absence of a reef flat plate), the seasonal timing of the event (wet vs. dry), and the presence of hand-dug wells that penetrate the reef flat plate. Actual tidal and rainfall data from regions in the western Pacific are applied to simulated 30-month recovery periods for hypothetical islands with properties and conditions characteristic of the western Pacific. For all scenarios, results indicate that 12 to 16 months are required to achieve 60% recovery of fresh groundwater. However, the time required to restore useful quantities of groundwater to acceptable salt concentration at depths typical of hand-dug wells is only 3 to 6 months. Of particular interest is the influence of the reef flat plate, which acts as a barrier to infiltrating seawater, thus preserving a pocket of confined freshwater during an overwash event and the recovery, which could probably be utilized if the necessary tools and equipment are on hand.

Rainfall Variability and Landuse Conversion Impacts to Sensitivity of Citarum River Flow

The objective of this study is to determine the sensitivity of Citarum river flow to climate change and land conversion. It will provide the flow information that required in the water resources sustainability. Saguling reservoir is one of the strategic reservoirs, which 75% water is coming from the inflow of Upper Citarum measured at Nanjung station. Climate variability was identified as rainfall variability. Sensitivity was calculated as the elasticity value of discharge using three-variate model of statistical approach. The landuse conversion was calculated used GIS at 1994 and 2004. The results showed that elasticity at the Nanjung station and Saguling station decreased from 1.59 and 1.02 to 0.68 and 0.62 respectively. The decreasing occurred in the before the dam was built period (1950-1980) to the after reservoirs operated period (1986-2008). This value indicates that: 1) Citarum river flow is more sensitive to rainfall variability that recorded at Nanjung station than Saguling station, 2) rainfall character is more difficult to predict. The landuse analysis shows that forest area decrease to ± 27% and built up area increased to ± 26%. Those implied a minimum rainfall reduction to± 8% and minimum flow to ± 46%. Those were caused by land conversion and describing that the vegetation have function to maintain the base flow for sustainable water resource infrastructure.

The urban water cycle approach in small development areas

Water cycle studies have been undertaken in several regional growth points in the UK as a strategic basis to support development planning in terms of assessing the adequacy of the existing water resource infrastructure. In this paper the application of the water cycle approach to the assessment of water and drainage availability for smaller site-based urban developments is evaluated, with an emphasis on the role of the storm-water component. A 170 ha urban regeneration site in the city of Birmingham, UK, is used to illustrate the process by identifying the principal water resource constraints, water usage rates and drainage issues associated with the development proposal. The scaled-down urban water cycle approach provides a valuable initial scoping of the development constraints and opportunities associated with water availability and drainage infrastructure provision. The analysis identifies the positive contributions that the storm-water component can make to other water resource functions and to reducing overall demands for water.

A comparison between the Gumbel-Hougaard and distorted Frank copulas for drought frequency analysis

Drought is a global phenomenon and is a common characteristic of extreme climate. It is widely considered as the world’s costliest natural disaster since their effects are especially devastating to the agricultural and social economy. Effective water resource infrastructure and management is required for the mitigation of drought, and this requires drought risk assessment. Essential characteristics of drought are severity, average intensity and duration, which are highly correlated. Copulas are multivariate uniform distribution functions with uniform marginals, which provide a flexible approach to model their relationship. For an extreme drought event to be modelled, the upper-tail dependence must be investigated. The construction of an alternative copula form is introduced through a transformation called a distortion, to allow for more versatile modelling of tail dependence. Data from a rainfall district in New South Wales is considered and the Gumbel-Hougaard copula and distorted Frank copulas are fitted to the drought characteristics. Goodness-of-fit and upper tail correlations of these copulas are analysed and discussed. Finally, conditional annual drought recurrence intervals are calculated and compared for these fitted copulas.

Irrigation Outreach in Afghanistan: Exposure to Afghan Water Security Challenges

Abstract:The authors, from Colorado State University were invited by the United Sates Department of Agriculture's Foreign Agriculture Service and Afghanistan's Ministry for Agriculture Irrigation and Livestock to lead a “train‐the‐trainer” workshop with Afghanistan's best and brightest irrigation outreach professionals. The six day workshop on the outskirts of Kabul helped clarify that prolonged conflict has damaged agriculture's access to what should be a plentiful supply of irrigation water. The violence of two wars still lingers today continuing to inhibit foreign aid's ability to rebuild Afghanistan's water resources infrastructure. In spite of these challenges participants in the workshop demonstrated remarkable resourcefulness and courage helping producers throughout Afghanistan take advantage of improvements as they came online. With continued assistance from Western researchers and extension professionals that is sensitive to the traditional methods of water administration, there is reason to be hopeful for the future success of Afghanistan's agricultural sector.

Water management institutions for more resilient societies

The management of water resources under conditions of uncertainty and scarcity is a fundamental determinant of the ability of societies to withstand unexpected shocks and extreme events. Conventional approaches to water resource planning aim to create reliable supplies. Practitioners often fail to identify their contribution to the broader goal of achieving social resilience rather than just technical system reliability. Recent work on understanding resilience in socio-ecological systems as well as on the management of ‘common pool’ natural resources such as water suggests that the contribution of planning processes to social resilience may in its turn contribute to the achievement of the narrow goal of system reliability. To illustrate this, the development of the water resource infrastructure system that underpins the South African economy is described with particular attention to the institutional processes that guide project selection and system operation.