Methodology for optimal pipeline routing using geographic information systems for rural water supply systems with gravity flow

This study presents a replicable methodology to define the optimal pipeline routing for rural gravity-fed water supply systems using geographic information systems (GIS). The research approach focused on areas characterized by low-income, semi-consolidated, and dispersed human settlements in high mountainous regions, posing significant challenges for water supply project planning. The methodology involved classification operations and weighted overlay of maps based on three main criteria: slope (Cr1), road network (Cr2), and coverage and land use (Cr3), which was classified into forest (Cr3-1), swamp (Cr3-2), crops (Cr3-3), lagoon (Cr3-4), bare soil (Cr3-5), pasture (Cr3-6), and shrub vegetation (Cr3-7). These criteria were assessed from four perspectives – environmental (P1), technical (P2), economic (P3), and social (P4) – weighted according to preference scales. The integration of these weighted criteria facilitated the identification of an optimal route, based on the calculation of the least-cost path that ensures satisfactory pressure conditions. The methodology was successfully applied in a real case study involving two analysis areas: an experimental area and an application area.