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.

The seasonal fluctuation of river depths is a critical factor in designing cargo capacity for river convoys and logistics processes used for grain transportation in northern Brazil. Water level variations directly impact the load capacities of pusher convoys navigating the Amazon rivers. This paper presents a machine learning model based on a multilayer perceptron artificial neural network developed with the aim of estimating the cargo capacities of river convoys one year in advance, which is essential for determining load capacities during dry periods. The prediction model was applied to the Tapajós River in the Amazon Basin, Brazil, where grain transportation is significant and relies on inland waterways. Navigability conditions were evaluated in terms of depth and geometric parameters. The results of this case study were satisfactory, validating the computational tool and enabling the assessment of capacity losses during dry periods and the identification of navigation bottlenecks. The main contributions of this work include optimizing river logistics, reducing costs, minimizing environmental impacts, and promoting the sustainable management of water resources in the Amazon. Conclusions drawn from the study indicate that the developed model is highly effective, with an R² of 0.954 and RMSE of 0.095, demonstrating its potential to significantly enhance river convoy operations and support sustainable development in the region.

The design of an access channel is based on regulations and recommendations from each country after considering natural and vessel-related criteria and characteristics, always focusing on navigation safety. This paper presents a set of criteria and technical parameters necessary for the planimetric dimensioning, in straight and curved sections, of navigation channels for inland waterways and port access channels, using a computational tool developed and called DimChannel (Channel Dimensioning Navigation), based on the recommendations of the World Water Transport Infrastructure Association (PIANC). The DimChannel was supported by the technical criteria present in recommendations of the PIANC, in which the characteristics of the vessels and waterways adopted in the standard are like the characteristics of Brazilian inland navigation. The software was validated through a case study in the lower Tapajós River, Amazon, Brazil. The results obtained showed that DimChannel is a tool of great importance for the planimetric dimensioning of navigation channels.

The characterization of intense rainfall in engineering projects is fundamental, mainly regarding the estimate of design flows necessary for designing hydraulic works. Intense rainfall events are commonly measured by Equations and curves that relate their intensity, duration, and frequency. Such relations, known as IDF, enable the hydrological characterization of a given region. This article presents a methodological design and results from both determination and spatialization of IDF curve parameters for the state of Maranhão. Historical series of maximum daily rainfalls obtained from National Water and Sanitation Agency (ANA) were used in 126 rainfall gauge stations and the Gumbel probability distribution estimated the maximum daily rainfall for 5, 10, 15, 25, 50, and 100 return periods. The Isozonal Method obtained the IDF correlations of intense rainfall events for 0,1. 1, and 24 h durations, and their performance were conducted by Nash-Sutcliffe R2 coefficient and Root Mean Square Relative Error (RMSE). “K, a, b, and c” parameters of intense rainfall equations were determined by optimization and convergence processes and their spatialization was carried out by interpolation by Inverse Distance Weighted (IDW), which enabled to determine the values of each parameter in regions without physical measurements of rainfall. Similarly, rainfall intensity was spatialized for the entire state. According to the results, the rainfall distribution in the state of Maranhão shows a variation in the indexes of precipitation, with the highest values found in areas located in central-southern, southwestern, and southeastern regions.

Ship repair has gained prominence as a service offered at the shipyards following a crisis in the shipbuilding industry, which has seen a fall in demand for new constructions, causing many companies in the sector to stall, especially shipyards. For a repair yard to be economically viable, in times of crisis, cost reduction is essential to make a sustainable business, so this comparative study aims to check the technical and economic feasibility of this change in the type of dry-docking. The present work deals with a comparative study between the use of the longitudinal slipway and the airbags for dry-docking and repair of river barges. The study sought to identify data from the vessels used for this project, to verify the average displacement of these vessels to analyze the airbags' carrying capacity, as well as the size of the winch to perform the dry-docking service. Since most repair yards use leased areas, the flexibility achieved with the use of airbags, as well as the reduced need for investments in the area, are benefits provided by using them. This work presented satisfactory results for the use of river barge docking airbags as a competitive alternative in repair services.