Determinação dos custos de Caminhos de Serviço utilizando o algoritmo de Least-Cost com auxílio do QGIS

Abstract

Haul routes (or services paths) are the roads through which the trucks responsible for transporting the soil necessary to carry out an earthwork project. The planning of these paths is generally donetrying to achieve the shortest distance between origin and destination locals of the material. Not choosing an optimal path increases the final cost of transportation, in addition to generating environmental and social upheavals. Thus, this research aims to compare the costs of haul routes generated by a Least-Cost Path algorithm using the costs of the shortest service paths. For this, a case study of duplicating the highway CE-040, located in the city of Caucaia, Ceará was carried out. QGIS , a free software that allows viewing, editing, creating, and analyzing maps through georeferenced data (also allowing the simulation of different scenarios), was also used in the study. With the help of QGIS, it was possible to identify different land uses in an area of 500 meters around the highway. After defining the cut and earth fill locations, the mineral deposits that would provide material for the filled areas were identified, and simulations of service paths were executed (by conventional analysis of shorter service paths, and using the Least-Cost Path algorithm, considering the criteria of slope of the terrain, existence of roads, presence of water bodies, and the possibility of deforestation. The costs for these variables were defined based on the literature, while its ponderation factors were based on the answers of 21 professionals in the area of Transport Infrastructure (obtained through a questionnaire). The average cost per kilometer for service paths with the shortest distance was R$ 8,508,165 while for the algorithm paths it was R$ 518,351. This difference is a consequence of the cost of environmental compensation necessary to carry out the project. However, in cases where the service paths with the shortest distance do not cross protected areas, the average cost is much lower than the costs of the paths generated by the algorithm. It is concluded that, in situations where the service paths do not cross bodies of water, the shortest path will have the lowest cost. Similar results are expected in cases of overcoming physical obstacles.