Avaliação dos usos múltiplos das águas e viabilidade de aproveitamento sa água da chuva na Reserva Extrativista de São João da ponta, bacia hidrográfica do rio Mocajuba-Pa

Abstract

The supply of water with quality, quantity, continuity and reasonable cost are necessary to ensure the benefits for human health, especially in riverside and rural communities. Unsustainable anthropogenic activities, such as livestock farming and agriculture, release of polluted effluents into water bodies that may cause changes in the physical, chemical, biological and microbiological characteristics of water, consequently limiting its use. The objective of this work is to evaluate the multiple uses of water and the feasibility of using rainwater in the São João da Ponta Extractive Reserve area, belonging to the MocajubaPa river basin, considering the demand and the local conditions of water supply. A theoretical and practical methodology was implemented using secondary data from the Brazilian Institute of Geography and Statistics (IBGE), National Information System on Sanitation (SNIS), Secretariat of State for Environment and Sustainability (SEMAS) and Municipal Secretary of Health, Surveillance and Control of São João da Ponta. For the construction of the primary database, interviews were carried out at the Municipality of São João da Ponta, at the Municipal Health, Surveillance and Control Secretariat and the Municipal Environment Secretariat, and forms were applied in the municipal headquarters of São João da Ponta and in the community of Jacarequara. The data was organized in a quantitative database to characterize the water consumption. From this information, it was evidenced that 76% of the population in the municipality of São João da Ponta is in a situation of poverty vulnerability. The average water consumption per capita resulted in 146 liters per day. The water consumption in agriculture is approximately 12698.9 m3/ha, and livestock demands on average 28 m³ / day per animal. Along the amount of water used for these economic activities, a greater problem is that farmers use water from nearby rivers and streams, which are the same bodies of water used for leisure by the local population. Another persistent problem is the fishermen’s use of poison from a toxic plant, known as "timbó”, which is a source of water contamination and cause of death for aquatic fauna. In addition, the physico-chemical and microbiological parameters of the water consumed in São João da Ponta were analyzed through data provided by the Municipal Health, Surveillance and Control Department, where it can be seen that approximately 83% of the samples have presence of Total Coliforms and 36.8% of E. Coli bacteria. According to information from the technical reports from the municipal headquarters, of 35 water samples collected, 94.29% were identified as unsatisfactory in the final result. An evaluation of rainwater utilization was also carried out; where the amount of rainfall in the study region was evaluated using information from rain gauges at Castanhal, Vigia and Curuçá monitored by the National Water Agency, In a complementary way, the regional estimates obtained from 43 ANA pluviometric stations (period 1985-2014) generated by the Laboratory of Hydroenvironmental Studies and Modeling. The roof measurements were taken considering the procedures adopted by the Water Utilization Research Group Of the Rainfall in the Amazon of the Federal University of Pará, through the Environmental Nucleus (NUMA) in partnership with the Institute of Technology. For the water tank sizing, five (5) methods recommended in the NBR 15527 were considered: (a) Rippl method, (b) Brazilian Practical Method or Azevedo Neto Method, (c) German Practical Method, (d) Practical Method English and the (e) Australian Practical Method. With all this information, it can be observed the region presents a rainfall index that guarantees good water supply for human consumption and some economic activities. For the processing of the data, the multi-criteria method Multipol was implemented. This tool helped in the comparison of the different actions for problems related to the water uses, considering multiple criteria and policies. It was evidenced that policies/actions of environmental education, agricultural management and environmental and water resources management policies are necessary to maintain a Blue scenario, in where water supply with adequate quality, loss control, and with ample access is guaranteed.