Hydraulic Infrastructure Research Articles

Uncertainty compliant design flood estimation

Hydraulic infrastructures are commonly designed with reference to target values of flood peak, estimated using probabilistic techniques, such as flood frequency analysis. The application of these techniques underlies levels of uncertainty, which are sometimes quantified but normally not accounted for explicitly in the decision regarding design discharges. The present approach aims at defining a procedure which enables the definition of Uncertainty Compliant Design (UNCODE) values of flood peaks. To pursue this goal, we first demonstrate the equivalence of the Standard design based on the return period and the cost-benefit procedure, when linear cost and damage functions are used. We then use this result to assign an expected cost to estimation errors, thus setting a framework to obtain a design flood estimator which minimizes the total expected cost. This procedure properly accounts for the uncertainty which is inherent in the frequency curve estimation. Applications of the UNCODE procedure to real cases leads to remarkable displacement of the design flood from the Standard values. UNCODE estimates are systematically larger than the Standard ones, with substantial differences (up to 55%) when large return periods or short data samples are considered.

Taking advantage of a new hydraulic infrastructure to study the sediment yield in a small basin of central Spain

Predicting the sediment yield at a catchment scale is one of the main challenges regarding fluvial geomorphology, however, it involves some difficulties. In this study, we have taken advantage of the construction of a new hydraulic infrastructure to study the sediment yield in its drainage basin between 2007 and 2010. This infrastructure is a small dam constructed in the riverine zone of the Entrepeñas Reservoir (upper Tagus catchment, central Spain), which generates a small water body, the Pareja Limno-reservoir (0.94 hm3), with a drainage area of 88 km2. It was built to mitigate the environmental and socioeconomic impacts of the construction and use of the Entrepeñas Reservoir, including the “arid band” phenomenon.Sediment yield was studied taking three sediment cores in the shallowest section, the central part and the deepest zone of the limno-reservoir. The layer of surface sediment was analized and a decreasing thickness of sediment towards the deepest zone of the limno-reservoir was observed. After assigning an area of the limno-reservoir to each core record, estimated annual sedimentation rate was 2032 Mg year-1, which supposes an annual storage capacity loss around 0.3% and a specific sediment yield in the drainage basin around 0.23 Mg ha-1 year-1. Comparing this value with previous soil loss studies performed in the basin, sediment delivery ratio in the basin varies from 2.2% to 3.8%.Both sediment yield and sediment delivery ratio showed low values for the Mediterranean context. The characteristics of the basin (small area, elongated shape with one main river channel, abundant vegetation), the absence of other erosive processes than rill and interrill erosion and the lower aggressiveness of rainfall in the center of the Iberian Peninsula may explain these results. The presence of the National Road N-204 surrounding the limno-reservoir may play a role in the low sediment delivery, especially from the adjoining hillslopes.

Análisis locacional de los yacimiento pétreos para la planeación territorial de infraestructura: El caso de la red pavimentada de Veracruz, México

The aim of the present work is to highlight the importance of territorial planning in the sustainable use of the raw material deposits located in the state of Veracruz, ranking first at the national level according to the National Inventory of Raw Material Deposits (NIRMD) 2011/2012 of the Secretariat of Communications and Transport (SCT). Raw material deposits are geological deposits of materials essential for the construction, maintenance and modernization of the basic infrastructure -communications and transport, electrical and hydraulic infrastructures-,social infrastructure–facilities to supply services and housing infrastructure-, and productive infrastructure –works aimed at the production and marketing of goods and services.

Methodology for Detecting Critical Points in Pressurized Irrigation Networks with Multiple Water Supply Points

The modernization processes of hydraulic infrastructures from old open channels to pressurized networks have increased water use efficiency along with a dramatic increase of energy consumptions. The significant energy requirements associated with the increment of the energy tariffs for irrigation involve higher production costs for farmers. Therefore, strategies to reduce energy consumption in irrigation districts are strongly demanded. Methodologies based on sectoring and critical points control have been applied to branched networks with a single water supply point, obtaining significant energy savings. In this work, a new critical point control methodology for networks with multiple sources has been developed: the WEPCM algorithm, which uses the NSGA-II multi-objective evolutionary algorithm to find the lowest energy consumption operation rule of a set of pumping stations connected to an irrigation network that satisfies the pressure requirements, when the critical points are successively disabled. WECPM has been applied to a real irrigation district in Southern Spain. The obtained results were compared with those achieved by the WEBSOM algorithm, developed for sectoring multiple source networks. The control of critical points by the replacement of two pipes and the installation of four booster pumps provided annual energy savings of 36 % compared to the current network operation. Moreover, the control of critical points was more effective than sectoring, obtaining an additional annual energy saving of 10 %.

Irrigation water management in Southern continental oasis of Tunisia

Although the available water resource is sufficient, it doesn't manage to satisfy the requirements of practiced crop (mainly date palms) in the small continental oasis Lazala (75 ha) situated in the South of Douz (Southern Tunisia). Indeed, the oasis showed a low frequency of water delivery turn for the whole irrigated surface (especially in summer). This incited us to evaluate the irrigation performance. To reach this objective, a comparative survey of the features of exploited water resource (60 l/s), the crop water requirements, the proprieties of irrigation network and the water management within the plots has been undertaken. The flow rate measurements that were carried along the hydraulic network and the spatial and temporal following of water management in some plots (experimental plots) during the 2012/13 irrigation season showed a poor overall irrigation efficiency (Eo = 28.41 %), a relatively low water application efficiency (Ea = 44.6 %) and a moderate value of water distribution uniformity (DU = 67 %) which are related mainly to the context of the region (climatic conditions and soil type), the technical dysfunctions of the hydraulic infrastructure and the individual farmer's practices within the plots (high irrigation duration, absence of water-saving systems in many irrigated areas and the bad land leveling).

Infraestructura hidráulica en Guadalajara para el abastecimiento de agua potable: el caso de sustentabilidad en las galerías filtrantes de Guadalajara

En el presente artículo se analiza la construcción de la infraestructura hidráulica para el abastecimiento de agua a la ciudad de Guadalajara y su continuidad, específicamente, la primera obra que permitió el abastecimiento de agua de manera colectiva; las galerías filtrantes, que basan su funcionamiento en aguas phreáticas y subterráneas. A su vez se describe la región hidrológica de Guadalajara y la importancia de los actores sociales que participaron en su construcción, así como la tecnología utilizada, que hicieron posible llevar agua a la ciudad. Por otra parte, se da seguimiento, en el tiempo, de las galerías filtrantes y su impacto en las zonas de extracción, sustentabilidad y permanencia de éstas como fuente de abastecimiento para la ciudad, considerando la riqueza de sus acuíferos, los cuales han sido olvidados o no tomados en cuenta por cuestiones políticas y económicas.

Decentralized water resources management in Mozambique: Challenges of implementation at the river basin level

In the context of integrated water resources management implementation, the decentralization of water resources management (DWRM) at the river basin level is a crucial aspect for its success. However, decentralization requires the creation of new institutions on the ground, to stimulate an environment enabling stakeholder participation and integration into the water management decision-making process. In 1991, Mozambique began restructuring its water sector toward operational decentralized water resources management. Within this context of decentralization, new legal and institutional frameworks have been created, e.g., Regional Water Administrations (RWAs) and River Basin Committees. This paper identifies and analyzes the key institutional challenges and opportunities of DWRM implementation in Mozambique. The paper uses a critical social science research methodology for in-depth analysis of the roots of the constraining factors for the implementation of DWRM. The results obtained suggest that RWAs should be designed considering the specific geographic and infrastructural conditions of their jurisdictional areas and that priorities should be selected in their institutional capacity building strategies that match local realities. Furthermore, the results also indicate that RWAs have enjoyed limited support from basin stakeholders, mainly in basins with less hydraulic infrastructure, in securing water availability for their users and minimizing the effect of climate variability.

Optimal Cost of Irrigation Network Design using Epanet

irrigation system is a hydraulic infrastructure that conveys water from the source to the consumers. The aim of the irrigation network design is to find the optimal pipe diameter for each pipe in the network for a given layout, demand loading conditions, and an operation policy. In this paper, we propose a model that uses Genetic Algorithm as an optimization scheme and link this algorithm with Epanet network solver to identify the least cost of pipes used in irrigation systems. Genetic Algorithm, being evolutionary, identifies the pipe diameters in a way that the total cost of the network so obtained, will be minimum. Our model selects the optimal pipe sizes in the final network satisfying all implicit constraints (e.g. conservations of mass and energy), and explicit constraints (e.g. pressure head and design constraints). The hydraulic constraints, deal with hydraulic head at certain nodes to meet a specified minimum value. If the hydraulic head constraint is violated, the penalty cost is added to the network cost.

Hydrochemical and physical processes influencing salinization and freshening in Mediterranean low-lying coastal environments

Ground- and surface water chemistry and stable isotope data from the coastal zone near Ravenna (Italy) have been examined to determine the geochemical conditions and processes that occur and their implications for fresh water availability in the various brackish/saline coastal environments. Fresh water in shallow coastal aquifers is often not enough to provide drinking water but it may sustain agriculture and natural environments such as pine forests, dunes and lagoons. The hydrochemistry and stable O and H isotopes of the ground and surface water near Ravenna were investigated in relation to these particular environments: rivers, drainage channels, lagoons, coastal dunes, paleo dunes, agricultural fields, and gravel pit lakes. Emphasis was put on the spatial distribution of ground water bodies with similar hydrochemistry. Most water samples are of the brackish to saline NaCl− type (NaCl concentration 300–20,000mg/L) with a negative Base Exchange Index (BEX) that is indicative of cation-exchange reactions caused by water rock interactions during the infiltration of saline water in a fresh water aquifer. Calcium-dominated fresh water is found only in the rivers, in the irrigation and drainage channels, and in a few ground water samples. The analysis of stable isotopes and SO42-/Cl- and δ18O/Cl− ratios shows that the major chemical and physical processes determining the salinity in the area are evaporation, mixing with saline water, cation exchange, oxidation of organic matter, migration and seepage of (hyper) saline water. The migration and upward seepage of (hyper) saline water driven by the hydraulic gradients induced by the drainage system causes the aquifer to become more saline over time. The areas where natural recharge occurs have always been small and this in combination with the Mediterranean climate results in very little natural recharge. Therefore, unless drastic changes to the hydraulic infrastructure are made, the coastal aquifer near Ravenna will become more saline and will threaten the ecology of current natural areas as well as the farmland.

From hydraulic infrastructures to basin management plans: limits and uncertainty on development of “protection from water” law

The law activity for soil protection and water discipline, normally still to the imposition of the hydrological constraint, shows a gradual change towards a stronger planning activity able to recognize an homogeneous basin area, although through great gaps and uncertainties of Public Administration about prediction, prevention and mitigation works. The privates intervention is also ignored, getting worse the soil fragility and the answer to the climatic emergences requiring, in this way, an improvement in participation and responsibility about destination property choices, sheltered for hydrogeological risk.

Integration of hydraulic infrastructure in metropolitan São Paulo. Prospects of change in a context of growing vulnerability

Integration of hydraulic infrastructure in metropolitan São Paulo. Prospects of change in a context of growing vulnerability

Challenges and Opportunities for Transboundary Water Cooperation in Central Asia: Findings from UNECE's Regional Assessment and Project Work

This paper provides an overview of topical issues and problems related to transboundary water resources in Central Asia and their management in the light of the Second Assessment carried out under the UNECE Water Convention (2009– 2011) as well as experiences from ongoing projects. The conflict between water use for hydropower and for agriculture, land degradation and negatively impacted ecosystems resulting from reduced flows and degraded water quality, poor condition of the hydraulic infrastructure, and the legacy of pollution all have implications for health, economy, and stability in the region. The outdated legal framework for regional cooperation on shared waters requires improvement to help find sustainable long-term solutions for reasonable and equitable use of shared water resources.

CHASING WATER: DIVERGING FARMERS' STRATEGIES TO COPE WITH THE GROUNDWATER CRISIS IN THE COASTAL CHAOUIA REGION IN MOROCCO

ABSTRACTIn many developing countries where agricultural groundwater use led to aquifer overexploitation, direct control over farmers' groundwater use is difficult to implement. This calls for the setting up, at least in the short term, of indirect policies, the efficiency of which will depend on farmers' strategies. The different strategies adopted by farmers to cope with the groundwater crisis are analysed in the Chaouia region in Morocco, where intensive agricultural groundwater use for the past 50 years has led to seawater intrusion in the seashore part and falling groundwater levels further inland. First, strategies may be based on ‘chasing’ groundwater, by deepening boreholes, bringing fresh water in sufficient quantity to the farms or renting fields in areas with sufficient fresh groundwater, so as to maintain a water‐intensive farming system. Second, strategies that may be designated as adaptive, entail adapting the farming system to the water available on‐farm given existing hydraulic infrastructures. These strategies may be considered as more sustainable with regard to water resources. Most of analysed strategies were not at the same time economically and environmentally sustainable. Possible policies to achieve economically and environmentally sustainable activities differ not only in the difficulty of implementing them, but also in the types of farms likely to benefit from them. Copyright © 2012 John Wiley & Sons, Ltd.

Water reservoirs, irrigation and sedimentation in Central Asia: a first-cut assessment for Uzbekistan

Water reservoirs play an important role in areas with limited and erratic precipitation where water is stored and re-distributed later for different purposes. Irrigation is primarily a major water consumer in arid countries of Central Asia for the economic development, employment and food security of the region. The major rivers of Central Asia (e.g., Amu Darya, Syr Darya, and Zerafshan) are turbid watercourses. Sedimentation reduces the main reservoir asset i.e., its volume capacity. In addition, vast territories of the region's countries have been transformed for agriculture to grow water intensive crops such as cotton, rice and wheat during the Soviet Union that dramatically accelerated soil erosion by water and wind. Thus, many man-made water reservoirs are affected by high sedimentation rates. Moreover, uneven spatial and temporal water resources and a Soviet-inherited unified hydraulic infrastructure have raised transboundary reservoir management issues over water resources allocation among the countries in the region such as Kyrgyzstan, Tajikistan, Kazakhstan, Uzbekistan and Turkmenistan. The rivers such as Syr Darya and Amu Darya are already regulated by more than 78 and 94 %, respectively and attempts for new reservoir projects upstream raises increased concerns of the downstream countries (e.g., the Rogun hydropower station in Tajikistan and the Toktogul reservoir in Kyrgyzstan). For instance, the uncoordinated use of reservoirs has caused the Arnasai lake problem in Uzbekistan with environmental, material damage and social unrest. The aim of this paper is first to review the present conditions and the role of man-made water reservoirs for irrigation in Central Asia with special focus on Uzbekistan, second to document past and current reservoir sedimentation conditions in Uzbekistan and third to discuss research carried out by Soviet and present-time local research community in the domain of erosion and sedimentation in the region.

From private initiative to public intervention in Spanish water management: the case of the Muga and Fluvià rivers (1850–1930)

During the second half of the nineteenth century and the first third of the twentieth century, Spain, along with some other European countries, underwent a process of transition regarding water resources management. One of the most obvious transformations that occurred during this period was the increasing lead taken by the government in the building of large hydraulic structures and the subsequent decrease in the influence of private initiative in this matter. The government's aim was to exploit the water resources provided by the rivers to their full, and in particular to use the water that was destined for irrigation to maximum effect. The repeated failure of projects promoted by private companies led the government, not without problems, to enact regulations and create hydraulic plans to be put into motion by the public sector. This change in focus is the key to understanding the frenetic pace of hydraulic infrastructure construction that occurred later and which made Spain one of the world's leading nations in terms of indicators such as the number of large reservoirs in use. This article focuses on the transition from private initiative to public intervention and evaluates the main stages of this process in Spain. The cases of the basins of the Muga and Fluvià rivers, located in the extreme north-east of the Iberian Peninsula in Catalonia, are described in light of this process. This research attempts to verify that despite their modest size and their distance from the main decision-making centres, these two cases reflected the situation at the national level. This was just one of the many local effects of the transition process of water resources management in Spain, even though the results of this transformation would be neither immediate nor effective in the short term.

Review: The Waters of Rome: Aqueducts, Fountains, and the Birth of the Baroque City by Katherine Wentworth Rinne

Katherine Wentworth Rinne. The Waters of Rome: Aqueducts, Fountains, and the Birth of the Baroque City . New Haven and London: Yale University Press, 2010, 262 pp., 47 color and 120 b/w illus. $65, ISBN 9780300155303 The copious literature on Rome's water supply extends back to Sextus Julius Frontinus's treatise on the ancient aqueducts, written late in the first century. Frontinus memorably remarked, “With such an array of indispensable structures carrying so many waters, compare, if you will, the idle Pyramids or the useless, though famous, works of the Greeks.” The Waters of Rome shares much with Frontinus's book, the fons et origo of studies on Rome's hydraulic infrastructure, including the emphasis that Katherine Rinne places on engineering over art and utility over display. In stressing utility, she also recalls Vitruvius, who considered water to be “the chief requisite for life, happiness, and for everyday use.” By comparison with the aqueducts supplying ancient Rome, the revival of the city's water supply in the Renaissance has received relatively less scholarly attention. Art historical interest has centered on the striking fountain displays of the seventeenth and eighteenth centuries, to the neglect of the more modest and utilitarian fountains of the sixteenth century. This neglect is even more evident where the largely invisible system of settling tanks and conduits that supply Rome's fountains, together with the drains that recycle and ultimately dispose of the water that flows from them, are concerned. The Waters of Rome, by telling the story of how the city's water supply came to be revived in the period 1560–1630, not only fills a significant gap in the scholarly literature but also underscores the linkage between water and urban development. Technology and topography figure prominently in Katherine Rinne's account. So, too, do patronage and social history; the question of how water was used by people from different strata of Roman society, from fullers and laundresses to princes and popes, emerges as a recurrent theme. The nine chapters comprising the book examine a number …

The role of statutory and local rules in allocating water between large- and small-scale irrigators in an African river catchment

This paper presents a case study of large- and small-scale irrigators negotiating for access to water from Nduruma River in the Pangani River Basin, Tanzania. The paper shows that despite the existence of a formal statutory water permit system, all users need to conform to the existing local rules in order to secure access to water. The spatial geography of Nduruma is such that smallholder farmers are located upstream and downstream, while large-scale irrigators are in the midstream part of the sub-catchment. There is not enough water in the river to satisfy all demands. The majority of the smallholder farmers currently access water under local arrangements, but large-scale irrigators have obtained state-issued water use permits. To access water the estates adopt a variety of strategies: they try to claim water access by adhering to state water law; they engage with the downstream smallholder farmers and negotiate rotational allocation; and/or they band with downstream farmers to secure more water from upstream farmers. Estates that were successful in securing their water access were those that engaged with the local system and negotiated a fair rotational water-sharing arrangement. By adopting this strategy, the estates not only avoid conflict with the poor downstream farmers but also gain social reputation, increasing chances of cooperative behaviours from the farmers towards their hydraulic infrastructure investments. Cooperative behaviours by the estates may also be due to their dependence on local labour. We further find diverging perspectives on the implementation of the state water use permits – not only between the local and state forms of water governance, but also between the differing administrative levels of government. The local governments are more likely to spend their limited resources on ‘keeping the peace’ rather than on enforcing the water law. At the larger catchment scale, however, the anonymity between users makes it more difficult to initiate and maintain cooperative arrangements.Keywords: water rights, legitimacy, conflict, subsistence irrigated agriculture, Tanzania

Modeling the fluid/soil interface erosion in the Hole Erosion Test

Soil erosion is a complex phenomenon which yields at its final stage to insidious fluid leakages under the hydraulic infrastructures known as piping and which are the main cause of their rupture. The Hole Erosion Test is commonly used to quantify the rate of piping erosion. In this work, The Hole Erosion Test is modelled by using Fluent software package. The aim is to predict the erosion rate of soil during the hole erosion test. The renormalization group theory – based k–ε turbulence model equations are used. This modelling makes it possible describing the effect of the clay concentration in flowing water on erosion. Unlike the usual one dimensional models, the proposed modelling shows that erosion is not uniform erosion along the hole length. In particular, the concentration of clay is found to increase noticeably the erosion rate.

The Role of Statutory and Local Rules in Allocating Water between Large- and Small-Scale Irrigators in an African River Catchment

This paper presents a case study of large- and small-scale irrigators negotiating for access to water from Nduruma River in the Pangani River Basin, Tanzania. The paper shows that despite the existence of a formal statutory water permit system, all users need to conform to the existing local rules in order to secure access to water. The spatial geography of Nduruma is such that smallholder farmers are located upstream and downstream, while large-scale irrigators are in the midstream part of the sub-catchment. There is not enough water in the river to satisfy all demands. The majority of the smallholder farmers currently access water under local arrangements, but large-scale irrigators have obtained state-issued water use permits. To access water the estates adopt a variety of strategies: they try to claim water access by adhering to state water law; they engage with the downstream smallholder farmers and negotiate rotational allocation; and/or they band with downstream farmers to secure more water from upstream farmers. Estates that were successful in securing their water access were those that engaged with the local system and negotiated a fair rotational water-sharing arrangement. By adopting this strategy, the estates not only avoid conflict with the poor downstream farmers but also gain social reputation, increasing chances of cooperative behaviours from the farmers towards their hydraulic infrastructure investments. Cooperative behaviours by the estates may also be due to their dependence on local labour. We further find diverging perspectives on the implementation of the state water use permits – not only between the local and state forms of water governance, but also between the differing administrative levels of government. The local governments are more likely to spend their limited resources on ‘keeping the peace’ rather than on enforcing the water law. At the larger catchment scale, however, the anonymity between users makes it more difficult to initiate and maintain cooperative arrangements.

Tras la tempestad, no llegó la calma: el Medio Vinalopó ante los temporales de septiembre de 1793

Las lluvias torrenciales del 7 y 8 de septiembre de 1793 afectaron de forma considerable a las tierras meridionales valencianas. El presente estudio analiza sus repercusiones en el Medio Vinalopó y los problemas que acarreó la ulterior reconstrucción de las infraestructuras viarias e hidráulicas en la villa de Aspe.