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Waterway transport is of great importance for the population of the Amazon Region. It is responsible for moving, according to Agência Nacional de Transportes Aquaviários (Antaq, 2018), approximately 9.8 million passengers and 3.4 million tons of cargo distributed by state, interstate longitudinal transport interstate and crossing. However, despite the great importance, there are several blockages related to the conditions of the roads and vessels in certain routes. The study in question proposes the use of a mathematical tool to analyze vessels from the relative efficiency involving parameters of input and output for two analysis scenarios: Energy Efficiency Analysis and Modality Analysis, being analyzed variables such as power, consumption, total time of the trip, total distance of the line of action, passenger capacity and ticket price. For that, the data of 652 vessels used in the Amazon region registered in the Brazilian states (Pará, Amazonas, Amapá and Rondônia) were verified, and from these data, a sample space of 148 vessels from the same utilization level was selected. With these data, a model was developed using the Data Envelopment Analysis (DEA) methodology, with the aid of the DEA-Solver software. After the use of the solver, the relative efficiency indexes of each vessel were obtained, allowing to rank and measure the efficient and inefficient Decision Units (DMU'S). Lastly, analysis of the general characteristics of efficient vessels were made in order to stratify the parameters that may have transformed them into efficient DMU`s, making it possible to trace a profile of the type of vessel employed in each type of line, thus helping in decision making of new projects.

Measurement of planktonic chlorophyll‐a—a proxy for algal biomass—in rivers may represent local production or algae transported from upstream, confounding understanding of algal bloom development in flowing waters. We modeled 3 years of chlorophyll‐a transport through a 394‐km portion of the Illinois River and found that although algal biomass is longitudinally widespread, most net production occurs at river control points in the upper reaches (up to 3.7 Mg chlorophyll‐a y−1 km−1). Up to 69% of the algal biomass in the upper river was a result of within‐reach production, with the remainder recruited from headwaters and tributaries. High chlorophyll‐a measured farther downstream was largely because of transport from source‐area control points, with substantial net losses of algal biomass occurring in the lower river. Modeling the often‐overlooked river transport component is necessary to characterize where, when, and why planktonic algae grow and predict how far and fast they move downstream. Plain Language Summary Planktonic algae in rivers may accumulate during periods of high productivity stimulated by favorable light, temperature, nutrient, and flow conditions, which can disrupt ecological processes and affect human uses including recreation and drinking water supply. Planktonic algae observed in rivers may occur because of local growth or transport from upstream source areas. Therefore, considering both local and upstream conditions may improve early warnings of potentially harmful blooms. Along a 394‐km stretch of the Illinois River, we found that most of the algae grew in the upper reaches and was then transported to downstream reaches, contributing to potential downstream harms such as excessive turbidity, organic carbon, biological oxygen demand, and algal toxins. We demonstrate how the often‐overlooked river transport component can be quantified to better identify where, when, and why algae grow in river networks. Key Points Planktonic algal biomass is pervasive in the Illinois River, yet production is favored at certain locations and times Most planktonic algal biomass was produced in upper‐reach control points that supplied downstream areas Transport analysis using local and upstream data improves understanding of river algal blooms

Plastic environmental pollution is threatening water resources, aquatic ecosystems, and human wellbeing but is still highly uncertain with global fluxes to sea of 0.4–13 Mt\\yr, and up to 517 Mt of mismanaged plastics on land. Catchment modelling tools are required to challenge current knowledge, simulate impacts of management initiatives, and complement global and observation-based studies. Here we present the first spatiotemporally explicit model for mismanaged plastic mobilization and transport from land to sea from the INtegrated CAtchment (INCA) family. INCA-Macroplastics encompasses all components of the catchment, is driven by available data (weather, population, solid waste) and enables calibration and validation against diverse observations (river monitoring, household surveys). INCA-Macroplastics was applied to the Imus River, Philippines, one of World's most polluted rivers. Given large uncertainties on catchment plastic retention, two calibrations and two emission scenarios were developed to describe catchment plastic fluxes, residence time and stocks over 1990–2020. Plastic fluxes to the sea are highly variable over years and seasons (55–75% exported during the wet season) and have increased exponentially over 1990–2020 from 5–100 to 2000–15000 tons\\yr. INCA-Macroplastics is the first model handling plastic accumulation on land and highlights the importance of extreme flooding events in mobilizing and transporting legacy plastics. Model outputs explicitly show that current land plastic pollution can impact fluxes to the ocean for up to 30 years into the future. INCA-Macroplastics is useful to provide tailored recommendations for local monitoring, testing waste management scenarios and pointing towards future research avenues.

Sustainability of transport systems is a key issue in transport. The main question is whether high levels of road and railway transport in areas along navigable waterways is an effective solution for this issue. The Danube waterway is an example. Generally, it is not observed that traffic performance is not as high as on the Rhine. This paper deals with the revelation of the available capacity of this waterway based on approximation functions and their comparison with real transport performances. This methodology points to the level of use of waterways. The connection of this model with the production of fossil fuels creates a basis for a case study. The case study in this paper offers a possibility for a sustainable and environmentally friendly transition from road transport to inland water transport on the example of specific transport routes. The main contribution of this paper is a presentation of the application of sustainable models of use transport capacity to increase the share of environmentally friendly and sustainable inland water transport. The conclusion based on the case study and materials is that the available capacity of inland water transport on the Danube could support the transition of traffic performances to sustainable and environmentally friendly means of transport.

The analysis of shoreline changes is very important for coastal planning and management. In territories such as Calabria (Italy), characterized by significant anthropogenic pressures and various eroded coasts, the knowledge of the shoreline changes, and the factors that influence them, is necessary for management and planning of coastal areas. In fact, shoreline position is one of the most important indicators of coastal dynamics. From this point of view recent advances in remote sensing and GIS techniques allow to estimate with great precision the shoreline changes over the years. The paper analyzes the shoreline changes near the mouth of the Sant'Agata River (Reggio Calabria, Italy), carried out through the comparison of various cartography data. Furthermore, the paper analyzes the main factors influencing the coastal dynamics in order to identify possible correlation between these factors and the shoreline changes. The analysis of these factors shows that, in this case study, the rainfall regime has a considerable influence on shoreline change. The methodology described in this paper is particularly useful for better understanding the factors that most influence the coastal balance and, therefore, is applicable to many contexts which are similar to the Sant'Agata river mouth.

This paper examines the distinctive distribution patterns of Amphore Crétoise (AC) 4 amphoras within Roman trade networks through critical assessment of the morphological attributes of this amphora type compared to AC1–3 jars and through consideration of the mechanisms that underlie these patterns. This builds on a growing number of studies that have focused on the design attributes of amphoras as important factors tied to their economic role. It also demonstrates the importance of engaging in more nuanced and detailed investigations that question assumptions about amphora distribution within the Roman world. The AC4 is the primary, and often only, Cretan type found at sites in Rome's northwestern provinces and along the Danube frontier. A narrower profile and smaller capacity appear to have made this amphora type more attractive than other Cretan forms for transport along river and overland routes.

The Danube has a length of 588 km in the Republic of Serbia. The water transport on this river is underused. The hazardous events have a great impact on the traffic on this river, and the understanding of these events is of great importance. This study focuses on hazardous events on the Danube with the main focus on the port of Novi. The hazardous events used in this study are extreme air temperatures, devastating winds, drought, and heavy precipitation. The hazardous events were represented using geographic information systems (GIS), geostatistics, and numerical methods. The potential of the river transport network and the port capacity were analyzed and compared with the hazardous events of the last 30 years. The results showed that three areas of the port are of great importance for port security, and two areas are extremely affected by hazardous events. The distance of the port of Novi Sad from heavy precipitation events is 6.8 km in the southwestern direction. The periods of extremely low precipitation (climatic drought) were in 1994, 2008, 2012, 2015, 2019, and 2021. Extreme average maximum temperatures were in 1995, 2008, 2010, 2013, 2015, and 2019. On the other hand, minimum average temperatures were in 1994, 1996, 1998, 1999, 2017, and 2018, and the strongest winds were in 1995, 1998, 2003, 2009, 2012, and 2014. The methods and techniques of GIS, used in this research, have confirmed new potential geographical positions of the port that can be better adapted to future climate changes. Another main objective of this research is to recommend better spatial planning and construction of new green corridors.

Small hydropower (SHP) facilities, defined variably but usually by installed capacities of <10–50 MW, are proliferating around the world, particularly in tropical and subtropical regions. Compared to larger dams, SHPs are generally viewed as having less environmental impact, although there has been little research to support that assertion. Numerous SHPs have been built, and many more are in development or proposed, in rivers that drain into the Pantanal, a world-renowned floodplain wetland system located mostly in Brazil. The upland tributaries are important sources of nutrients to the Pantanal, affecting the biological productivity of downstream floodplains. This study presents measurements from upstream and downstream of 25 current hydropower facilities, most of which are SHPs, throughout the upland watersheds of the Upper Paraguay River basin to reveal how these facilities may affect the concentrations and transport of nutrients in rivers flowing to the Pantanal. Artificial neural network models estimated the impact of building 80 future SHPs on nutrient transport into the Pantanal, based on observations at current facilities as well as the spatial distribution of future facilities. Overall impacts of current hydropower facilities were not large, and in most cases were indistinguishable based on comparisons between upstream and downstream. The short water residence times of reservoirs associated with SHPs likely explain their tendency to have little or no effect on nutrient transport. However, model predictions for hydropower facilities that may be built in the future, many on rivers with higher discharge and sediment loads, point to significant reductions in overall TN (8%) and TP (29%) transport, with potential negative consequences for river and floodplain productivity. Negative impacts may be either because the rivers carry low nutrient concentrations and are thereby sensitive to oligotrophication, or they are particularly important overall nutrient sources supporting ecosystem productivity in downstream rivers and floodplains. Together with a parallel study of sediment transport, these results support recommendations that several river systems presently lacking dams in their lower reaches should be excluded from future hydropower development to maintain the nutrient and sediment supply to the Pantanal.

Thirty-eight samples were taken from the banks of the Sanaga River and its main tributaries draining different plant ecosystems, but also from rivers in the coastal basins of Cameroon. This study aims to characterize the origins of pollen and the dominant mode of transport of pollen inputs to the continental shelf. The classical method of pollen spectra analysis and multivariate statistical analysis revealed three groups of samples corresponding to the three main ecosystems in which the samples were taken. Pollens typical of the northern savannas are found in the spectra of samples taken further downstream from the Sanaga River in forest areas and not in samples from rivers draining mainly the forested coastal basins. The level of similarity between groups and the spatial evolution of spectra from upstream to downstream are related to the fluvial transport of pollen.

The case study presents the results of numeric simulations of deformations of Vistula River bed downstream the Włocławek Dam, with and without development of the downstream dam cascade. Calculations were performed using a one-dimensional flow model MIKE11 with a river transport module. Using synthetic inflow hydrographs, predictions were performed for 39 year period (2016–2055). Results indicate that the construction of the dam cascade will reduce the erosion of the river bed downstream the Włocławek dam.