Assessment of Climatic and Anthropogenic Controls on Bridge Deck Drainage and Sediment Removal

Bridge deck drainage is essential to prevent hydroplaning and maintain safety along major roadways. With projected changes in climate, current designs may not be sufficient and a better understanding of the primary controls (climate, bridge deck, and inlet design) on the hydraulic efficiency and sediment removal of drainage systems is needed to maintain public safety. To evaluate the controls on hydraulic drainage efficiency, 576 controlled laboratory experiments were conducted testing grate type (rectangular bar vs. curved vane) and downspout configuration (square vs. circular and 20 cm vs. 25 cm) across a range of flow rates, cross slopes, and longitudinal slopes. An additional 144 sediment erosion experiments were performed to identify controls on the removal of sediment. Hydraulic testing indicated that inflow driven by climate is a primary control on drainage efficiency and spread of water on a roadway. For anthropogenic controls, downspout opening size was found to be the primary control followed by longitudinal slope. Sediment removal results indicated that inflow regime and grate type were the primary controls on the sediment removal rate. Given that inflow, driven by climate, is a control on both hydraulic and sediment removal performance, hydraulic engineers should consider forecasted changes in rainfall intensity in their present-day drainage designs. We provide design guidance and discussion for developing a proactive approach to hydraulic infrastructure in the face of future climate uncertainty.

Cartographie de L’accessibilité et Gouvernance Locale des Infrastructures Hydrauliques dans la Commune D’avrankou Au Sud-Est du Benin

In the Municipality of Avrankou, the populations experience enormous difficulties in obtaining water supplies despite the availability of a large number of water points. This work aims to analyze the distribution of hydraulic infrastructures and their mode of management in the said Municipality. To map the availability of water points and study their management method, 115 households and 17 resource people were interviewed. Arc GIS 10.5 software was used for the spatialization of the data. The results reveal that the Municipality of Avrankou has 301 hydraulic infrastructures, of which 83 are functional and 218 are non-functional. The functional water points are made up of 42 Boreholes equipped with Human Motricity Pumps and 41 Fountains supplied by 2 Village Water Adductions. Out of the 84 villages of the Commune, only 39 villages have access to functional water points, either 46.42% and among them, 12 villages have double access to it. Thus, 45 villages would have access if the authorities repaired non-functional water points and 15 villages if other structures were built. The management methods of the hydraulic infrastructures adopted are leasing and delegated management. These management methods have enabled the town hall to mobilize resources to finance development actions. The unequal distribution of hydraulic infrastructure is proof of the lack of a regular maintenance system and the absence of spatial planning tools in this sector. To remedy this, it is therefore necessary to involve the populations more and make them responsible for the management of water points and also to repair non-functional hydraulic structures. Dans la Commune d’Avrankou, les populations éprouvent d’énormes difficultés pour s'approvisionner en eau malgré la disponibilité d’une importante quantité de points d’eau. Ce travail vise à analyser la répartition des infrastructures hydrauliques et leur mode de gestion dans ladite Commune. Pour cartographier la disponibilité des points d’eau et étudier leur mode de gestion, 115 ménages et 17 personnes ressources ont été interrogés. Le logiciel Arc GIS 10.5 a été utilisé pour la spatialisation des données. Les résultats révèlent que la Commune d’Avrankou dispose de 301 infrastructures hydrauliques dont 83 fonctionnelles et 218 non fonctionnelles. Les points d’eau fonctionnels sont constitués de 42 Forages équipés de Pompe à Motricité Humaine et 41 Bornes Fontaines alimentées par 2 Adductions d’Eau Villageoise. Sur les 84 villages de la Commune, seulement 39 villages ont accès aux points d’eau fonctionnels soit 46,42 % et parmi eux, 12 villages y ont doublement accès. Ainsi, 45 villages auraient accès si les autorités réparaient les points d’eau non fonctionnels et 15 villages si on construisait d’autres ouvrages. Les modes de gestion des infrastructures hydrauliques adoptées sont l’affermage et la gestion délégataire. Ces modes de gestion ont permis à la mairie de mobiliser des ressources pour financer les actions de développement. L’inégale répartition des infrastructures hydrauliques est la preuve de l’inexistence d’un système de maintenance régulier et de l’absence des outils de planification spatiale dans ce secteur. Pour y remédier, il faut donc impliquer davantage et responsabiliser les populations pour la gestion des points d’eau et réparer également les ouvrages hydrauliques non fonctionnels.

Study on the hydrothermal coupling characteristics of polyurethane insulation boards slope protection structure incorporating phase change effect

The canals are essential for agricultural irrigation, shipping and industry as important hydraulic infrastructure. In the seasonal freeze regions, the water conveyance canals are damaged due to the effects of freeze–thaw cycles. The freeze depth of soil in the water transfer canal varies considerably due to changes in temperature and water content. This paper compared the relationship of freeze depth, temperature and water content by field tests and numerical calculation methods by incorporating phase change. The results from present study showed that the decrease in temperature causes the water in the soil to freeze, the ice front migrated downwards, and the water in soil below ice front gradually migrated towards the ice front resulting in a large difference in water content of the soil before and after freezing. The Polyurethane insulation board + Concrete board slope structure (PC) as an insulation slope structure was proposed in this paper to mitigate the effect of freezing and thawing on the water conveyance canals. The freeze depth decreased significantly under the protective effect. In addition, this paper compared the anti-frost effect of different thicknesses of polyurethane insulation boards, and the results provided a reference for the anti-frost design of water conveyance canals.

Evaluation of Geology and Hydrogeology of the Water Leakage in Hammam-Grouz Dam, Algeria

Water has been known since antiquity as the catalyst and survival of mankind. Therefore, hydraulic structures have been constructed to resolve various hydraulic problems which are exposed such as: pollution, eutrophication, accelerated siltation, intense evaporation and water leakage. In Algeria, the problem of water leaks has appeared in many dams, among them the Hammam Grouz dam in the north-east of the country. Indeed, the hydro-technical work is considered as the most threatened in the country by this thorny problem. During the period between 1984-1987, there is a lack of suitable site for dam construction in this area led the services concerned to build this infrastructure in a cluse composed of limestone (Cenomanian) moderately karstic which are characterized by dissolutions concentrated along the joints. This site was consolidated and sealed during the construction of the dyke dam that allows its exploitation before a real test. However, it should be noted that the water level rose above the normal reservoir level for the first time (January 26, 2003) showed that this site can no longer withstand the strong pressure forces caused by the coastline water. In fact, significant water leaks have appeared at the lower gallery and downstream foot of the right bank. The following variation of water leaks over time, it can be observed that a convergence of stability of the level of the water level in the bowl to levels not exceeding 718 m which is the equivalent of less than 1/3 of the original storage capacity of the dam. The appearance of significant water leaks at the Hammam Grouz dam as soon as the spill was first discharged indicated that the sealing works carried out during the construction of the dyke had either lost their effectiveness or they were not perfect. The settlement works carried out today at the level of the basin and the banks of this hydraulic infrastructure. Despite having minimized the flow of the resurgences that appeared downstream of the dike, they did not solve the problem definitively. This may result in the appearance of a place of water leaks. Indeed, during the hydrological year 2007/2008, the appearance of a vortex in November 2007 within the lake rendering the dam of Hammam Grouz useless because it was empty during the first three months of the year 2008, in addition to the water loss that threaten them. This phenomenon floods the lower gallery of the dyke with each rise of the level of water beyond a limit threshold. Hence, it is impossible to perform some monitoring related to stability control. The harmful effects of the problem of water leakage, the stability of the dike and the quantity of water stored, especially with water scarcity in this semi-arid region, require treatment of this phenomenon. The most adapted techniques are the use of sealing materials. Having the same characteristics as the places to be waterproofed and which adapt sufficiently to their geological formations, the allocation of sealing works to a highly qualified co-contractor, are of great importance in order to provide satisfactory sealing results to make it watertight in order to operate it properly. Doi: 10.28991/HEF-2021-02-03-08 Full Text: PDF

GIS-based Assessment of Morphological and Hydrological Parameters of Ribeira dos Socorridos and Ribeira do Vigario Basins, Madeira Island, Portugal

The main objective is to identify hydraulic and hydrologic features of drainage basins of Ribeira dos Socorridos, and Ribeira do Vigário located in Madeira Island, (Câmara de Lobos).So, the research analyzed, theoretically, the sediment transport in the above-mentioned cases, and consequently, possible measures for torrential correction were studied. Thereby, hydrographic, geological, and hydrological features of this Archipelago were analyzed in the first phase. Thus, a geographic framing of drainage basins was made - using digital terrain models and deep characterization of the understudy drainage basins. In this regard, it was possible to obtain data regarding the geometric, relief, and drainage system components, using the Geographic Information Systems (GIS).In fact, the use of GIS makes it possible to characterize all descriptive indices/parameters of a hydrographic basin. These indices/parameters linked to the region's climate explain the need for human intervention to construct river hydraulic infrastructure and implement mitigation measures.Moreover, torrential correction techniques were presented to anticipate and mitigate this typology of events. Contextually, this study provides us several goals to consider in the future, including the most relevant actions and guidelines to enhance the characterization of drainage basins and clarify the characterization and accounting of sediment transport.

Assessment of Climate Change Impact on Probable Maximum Floods in a Tropical Catchment

Increased extreme rainfall due to climate change will increase the probable maximum flood (PMF) and pose a severe threat the critical hydraulic infrastructure like hydroelectric and flood protection dams. As the rainfall extremes in tropical regions are highly sensitive to global warming, increase PMF can be much higher in the tropics. A study has been conducted to assess the impact of climate change on PMF in a tropical catchment located in peninsular Malaysia. A lumped hydrological model, Mike NAM, is calibrated and validated with observed climate and inflow data of Tenmengor reservoir, located in the state of Perak of Peninsular Malaysia. Regional climate model projected rainfall is used to generate probable maximum precipitation (PMP) for future periods. The hydrological model is used to simulate PMF from PMP estimated for the historical and two future periods, early (2031−2045) and late (2060−2075). The results revealed the NAM model could simulate the river flow with a Nash–Sutcliffe efficiency of 0.74 and root mean square error of 0.51. The application of the model with projected rainfall revealed an increase in PMP by 162 to 507% and 259 to 487% during early and late periods for different return periods ranging from 5 to 1000 years. This would cause an increase in PMF by 48.9% and 122.6% during early and late periods. A large increase in PMF indicates the possibility of devastating floods in the study area due to climate change.

Unpacking Decades of Multi-Scale Events and Environment-Based Development in the Senegalese Sahel: Lessons and Perspectives for the Future

A major challenge faced by human societies is to promote development that truly makes difference for people without jeopardizing their environment. This is particularly urgent in developing countries where, despite decades of development programs, local populations often live under poverty thresholds. With this study, we participate in the ongoing debate about the necessary global revision of development theory and practice in the rural Sahel. We retrace the development trajectories in the Ferlo, the northern silvopastoral zone of Senegal. We highlight how development has evolved from the 1940s to the present, from centralized development action programs focused on hydraulic infrastructure to current polycentric development with growing environmental concerns. We highlight multi-scale events that have influenced the successive development paradigms in the area. Focusing on the past thirty years, we analyzed twenty-five environment and natural resource management-oriented projects, describing the evolution of their objectives and actions over time and identifying recurring flaws: redundancy, lack of synergy, and questionable relevance to local needs We put forth that a more resilient thinking-based development paradigm is necessary to guide the growing number of environment-oriented development actions, including the African Great Green Wall, for which massive investments are ongoing throughout Ferlo and across the Sahel.

Constructing the water works, constructing the narrative

The first decades of the 20th century were a great period in urban municipal politics that gave rise to the modern theory and practice of public health. In Toronto, the iconic R.C. Harris Filtration Plant (1941) stands as an emblem of modernity and the marvels of hydraulic engineering that assured every citizen of the social right to clean water. We no longer celebrate the material networks of water supply such as R.C. Harris and his public works department fought to achieve; filtered H20 has become another commodity with no reference to the production process. In this thesis I explore the local, historical specifics of water issues embedded in this site and suggest ways that they might contribute to the renewed visibility of hydraulic infrastructure; a re-imagined materiality that might in turn inspire a more sustainable, collective water citizenship.

Constructing the water works, constructing the narrative

The first decades of the 20th century were a great period in urban municipal politics that gave rise to the modern theory and practice of public health. In Toronto, the iconic R.C. Harris Filtration Plant (1941) stands as an emblem of modernity and the marvels of hydraulic engineering that assured every citizen of the social right to clean water. We no longer celebrate the material networks of water supply such as R.C. Harris and his public works department fought to achieve; filtered H20 has become another commodity with no reference to the production process. In this thesis I explore the local, historical specifics of water issues embedded in this site and suggest ways that they might contribute to the renewed visibility of hydraulic infrastructure; a re-imagined materiality that might in turn inspire a more sustainable, collective water citizenship.