Avaliação da eficiência de cisternas utilizadas no P1MC frente aos diferentes regimes pluviais do Rio Grande do Norte

Abstract

This research proposes an analysis of 16-cubic-meters cisterns’ efficiencies used in standardized way in the Program 1 Million Cisterns (P1MC). The efficiencies were calculated through simulations of the cistern’s water balance for a period of more than 53 years of daily precipitation data. Rainfall data was used for four regions of homogeneous precipitation in the RN state and the roof area for water catchment was varied in 40 m², 60 m², 80 m² and 100 m². The other parameters were used according to the P1MC’s practice, demand of 14 liters.inhabitant-1.day-1; 5 inhabitants per residence; it was considered a runoff coefficient of 0,80 and a First-Flush of 1mm. The results indicated that only in regions located in the state’s semi-arid region and catchment areas below 60 m², the efficiencies were below 90%, value that NBR 15.527 indicates as desirable. For these cases, which represent less than 32% of the simulation results, it had been confirmed a program`s ineffectiveness due to low efficiencies shown. It was concluded the necessity of more size types of tanks or extension of the catchment area where there is low efficiency to achieve 90% efficiency to meet the priority human demands.