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Item type:Publication, Towards adopting open and data‐driven science practices in bed form dynamics research, and some steps to this end(Wiley, 2020-01-15)Abstract In recent years, open and data‐driven science has fostered very important scientific breakthroughs. This study describes the challenges and opportunities for the scientific community devoted to bed form dynamics research in adopting such scientific paradigms through, for example, engineered data sharing, formal recognition of scientists who collect the data, and collaborative development of free accessible software. It highlights that once these actions are completed, the potential application of deep learning techniques could substantially improve bed form models and the scientific understanding of bed form dynamics. Likewise, it discusses the potential of Bedforms‐ATM, a free available software, to standardize some bed form data analysis techniques. We propose that the technical challenges be tackled by following scholarly accepted/proposed standards (e.g. FAIR Guiding Principles, Geoscience Papers of the Future), using the body of knowledge being built on the matter by some institutions (e.g. Federation of Earth Science Information Partners), and through technical discussions at scientific meetings such as MARID. © 2020 John Wiley & Sons, Ltd. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Spoilt for choice -- when to use which bedform identification tool for what purpose?(Wiley, 2021-12-28)Subaqueous dunes are fascinating morphological features that exist in diverse environments such as the deep sea, continental shelves and inland streams or rivers. Due to their rhythmic and oftentimes very frequent occurrence along the predominant flow direction, the analysis of these bedforms is usually assigned to bedform identification tools. Such algorithms automatically determine crest and trough locations and calculate dune dimensions accordingly. Over the last years, the number of these tools has notably increased with specialized methodologies for every environment and bedform scale. Although many of them are readily available to interested researchers, there may be uncertainty as to which method should be applied in view of a specific research question. As authors of some of the most recent bedform identification tools, we have started to systematically compare our approaches by analyzing an agreed set of diverse bathymetric data. The bed features assessed in this context range from river dunes formed under unidirectional flow over tidally constrained compound dunes to bed elevation profiles gained from flume experiments. The resulting dune characteristics, which each scientist obtained by applying his/her particular algorithm, are thereupon contrasted in a qualitative and quantitative manner uncovering the similarities and differences between individual methodologies. Our preliminary results suggest a strong influence of the original focus of each algorithm and therefore corroborate the need for systematic comparison. In the next step, the gained insights will be used to find and explain the optimum fields of application and, in the end, provide user-oriented guidelines that may support the bedform community in deciding which identification tool should be used for what purpose. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Hydrometeorological data-based methodology for navigability risk analysis at waterways: case study for Magdalena River(American Society of Civil Engineers (ASCE), 2021-09-01)The characterization and quantification of risk in port activities are essential to determine the main factors that may cause incidents and to establish risk mitigation strategies to improve the safety and operability of ports. This study presents a novel methodology to analyze the hydrometeorological risk of navigation in fairways and port activities, which is applied to the study case of the 22-km section of the lower Magdalena River, near the port of Barranquilla (Colombia). The methodology is based on probabilistic models of dominant hydrometeorological variables (e.g., water depth, flow velocity, wind magnitude, and wave height) identified via hazard and operative (HAZOP) studies. It allowed for quantifying likelihood and vulnerability levels obtained by empirical functions representing monthly spatio-temporal risk. It can be applied at any stage of fairway design and is highly replicable at other geographical conditions. The results for the study area show that the main risk factors for the reference vessel (i.e., SUPRAMAX) are the wave height and the fairway depth, which on up to 15% of the cases restrict navigation and induce deviations and economic losses to the port authority. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Bridging worlds in bedform research with an open access, universal toolbox: the Bedform Analysis Toolbox(Wiley, 2021-12-21)Bedforms (ripples, dunes, sandwaves) are ubiquitous features in many sandy subaqueous settings. They have been observed in a wide variety of flows, including rivers, the surf zone, estuaries, tidal inlets, shallow seas, and deep waters. Bedforms exert a major influence on a range of processes, from small-scale turbulence and sediment transport to large-scale coastal geomorphology. Therefore, knowledge on the dimensions, morphological characteristics and dynamics of large bedforms is relevant for a range of fundamental and applied research. Several methods have been developed over the years to characterise bedform dimensions from bathymetric data. Each method has been created for a specific (e.g. discriminate bedform scale, calculate bedform size and/or shape, detect crestlines) and environment (unidirectional, constrained tidal or open marine) and with a certain accuracy (precise time-consuming detection or coarse rapid detection). Although some of these methods are freely available, it may be difficult for scientists to use them due to the specificity of their design. A unique toolbox which combines the available methods into one easy-to-use software would help the bedform community advance knowledge on bedform research by facilitating the analysis of bedform characteristics. This should also include recommendations of which method should be used for which purpose. The present project aims at creating a Bedform Analysis Toolbox which combines several methods already available. The toolbox will be made open source and freely available. Feedback on the need of the community or required design and specificity would help us create a toolbox which is useful to many scientists. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Development and validation of a novel metric for describing the three-dimensionality of bed forms(Elsevier, 2021-10-01)Description and characterization of bed forms in different environmental settings requires an assessment of three-dimensionality. This is related to the irregularity of the bed form shape and the degree of dissimilarity from strictly 2D bed forms, those bed forms that are straight, continuous, lack of defects and are arranged in groups with an aligned pattern. Three-dimensionality assessments are commonly vague and subjective, and even when some numeric relations for three-dimensionality quantification exist, they are based mainly on the characteristics of the bed form crest and cannot be easily implemented or automated to be applied to bed form fields. In this work an objective and general method is presented for the assessment of bed form three-dimensionality. The method introduces a three-dimensionality index Tb, which considers the correlation between bed profiles orthogonal to a target direction and a reference mean longitudinal bed profile. It is shown that the suggested method can serve as an objective characterization tool for ranking the three-dimensionality of groups of bed forms at different scales, with a continuous scale between 0 and 1. For archetypical bed forms, which were synthetically generated from sinusoidal functions, Tb successfully reproduced the intuitive hierarchy of the degree of three-dimensionality. Moreover, when applied to real subaqueous dunes in one-directional decelerating flows, Tb was able to reveal a gradual decrease of the bed configuration three-dimensionality with flow strength increase. The method also proved to be useful to automatically infer the orientation angle of bed forms by finding the angle of minimum three-dimensionality. This is exemplified with superimposed ripples on a Martian barchan-dune, using the grey scale of a high-resolution image instead of bed elevations. The new approach may be also useful to validate morphodynamic models, and to develop three-dimensionality maps for identifying heterogeneous regions or zones with a bad quality of survey data. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Agricultural land degradation in Peru and Bolivia(Springer Nature, 2022-01-01)Soil erosion is the most prominent evidence of soil degradation and is regarded as the main type of agricultural land degradation worldwide. The objective of this contribution is to assess soil degradation associated with agricultural lands in Peru and Bolivia. The assessment is mainly based on a recent soil erosion survey; maps describing soil erosion rates across 5 km grids for the years 1990, 2000, 2010, and 2020; and global observations of agricultural land areas. We observe that soil erosion rates in agricultural lands from Peru and Bolivia are steadily growing. We also observe that (1) the highest quantities of soil erosion are found in the Andean highlands and the largest areas of soil denudation in the Amazonian sections, and (2) there is a positive relation between erosion degree and soil organic carbon stock. The main drivers of soil erosion are the intensive agriculture production and fertilizer use that have increased in Peru and Bolivia. This land use intensification in both countries is also the driver of other land degradation factors such as soil salinization and soil pollution. The use of sewage (e.g., gray water) in urban and peri-urban agricultural areas increases the risk to soil health by inducing the dispersion of microplastics assisted by soil erosion. Overgrazing affects a large portion of the highlands from both countries. Very limited information of the extent of slash-and-burn fire agriculture exists; however, this practice is mostly observed in the Department of Santa Cruz (Bolivia). To prevent or minimize the pressure on soil resources associated with soil erosion or soil pollution, we highlight the need to support sustainable soil management practices and responsible use of fertilizers in agricultural land. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Combining hands-on and virtual experiments for enhancing fluid mechanics teaching: A design-based research study(John Wiley and Sons Inc, 2022-11-01)Fluid Mechanics courses comprise both theoretical and laboratory modules. In developing nations, computer‐assisted techniques are not commonly applied in Fluid Mechanics instruction. Forced by the COVID‐19 pandemic, South American universities are, however, using them for online teaching. This contribution presents an 8‐semester (2016–2019) educational intervention over an undergraduate Fluid Mechanics course. It mainly blends physical (hands‐on) and virtual experiments (computer fluid dynamics‐based simulations) for the laboratory module, which are complemented by flipped classroom‐based prompts for the theoretical module. The intervention follows design‐based research as a research method and is guided via conjecture mapping and fidelity of implementation standards. Our results suggest that the intervention improves fluid mechanics laboratory instruction, although improvements depend upon the participation of other educational actors such as teaching assistants and laboratory technicians to some extent. Laboratory report grades (the assessment instrument) follow the Gompertz probability distribution. Following UNESCO standards, a portion of the intervention output is shared as open educational resources. This contribution encourages upscaling the educational intervention through the formation of cooperative clusters to build common‐pool Fluid Mechanics resources. Learning scientists have underlined the need to better understand laboratory instruction processes. They have been addressed in very few instances in developing countries. We believe that this study has the potential to provide valuable insights on the matter. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Parsimonious cumulative process-based workflow for early sanitation infrastructure evaluation (CPESI): Case study of Riohacha, Colombia(Elsevier Ltd, 2024-09-01)In small and medium-sized cities from developing countries, the early selection of integrated wastewater management systems is challenging due to the lack or limitations in the availability of basic information and skilled professionals. This study presents CPESI, a cumulative processes-based parsimonious workflow for early evaluation of sanitary infrastructure. CPESI is aimed to provide a simple, objective, and systematic analysis framework at the early stages of development of sanitary systems in underdeveloped nations. CPESI was applied to evaluate sanitation system alternatives for Riohacha (Colombia) in three stages, namely, (1) an initial assessment of citizens acceptability of the alternatives and analysis of basic laboratory testing; (2) a process analysis and technical-economic evaluation of alternatives based on CAPEX and OPEX indicators; and (3) engineering judgment to select the most viable alternative through multi-criteria evaluation. Our results suggest that CPESI could be highly replicable in developing countries and that it has the potential to expedite the alternatives assessment process when compared to data-intensive methods and expert requirements. Several researchers have highlighted the need to develop tools suitable to evaluate SDG 6 in developing nations. We believe that CPESI has the potential to contribute to that end. - Some of the metrics are blocked by yourconsent settings
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Item type:Publication, Bedforms characterization of the Magdalena River Estuary: A comparative analysis using the Mahalanobis distance(American Geophysical Union, 2024-10-25)This study comprehensively analyzes the bedforms within the Magdalena River Estuary (MRE). Three sets of high-resolution bathymetric surveys conducted under varying climatological conditions were used to quantify the morphometry of the bedforms and analyze their evolution. Bedform dynamics were linked to hydrodynamic and sedimentologic processes previously documented for the MRE. The bedforms’ geometry of the MRE was compared with those of several estuaries and rivers using the Mahalanobis distance. The results show that during the low-discharge season, the salt wedge intrusion into the MRE inhibits the development of bedforms, resulting in a lower-stage plane bed. Meanwhile, larger dunes become predominant along the river channel when the salt wedge is flushed out of the estuary during high discharges. However, the symmetric shape of these dunes reflects the tidal influence on the river channel dynamics even during high discharges. Applying the Mahalanobis distance to the MRE and other fluvial and estuarine systems allowed us to systematically identify several geometric characteristics distinguishing between estuarine and fluvial bedforms. This research also proposes a nomenclature for standardizing geometric features in bedform studies.