Janiro Costa Rêgo

Influence of sewage disposal on the water quality of the Sucuru River alluvial aquifer in the municipality of Sumé-PB, Brazil

The objective of this study was to evaluate the influence of sewage discharge on the quality of the water exploited from the Sucuru River alluvial aquifer, located in the municipality of Sumé, Paraíba state, Brazil. The study was based on physical-chemical and microbiological analyses of the waters from nine wells located along the alluvium. The results of the indicators showed that the alluvial aquifer studied has the capacity to filter and disperse pollutants. It is possible to observe a gradual reduction of chlorides, chemical oxygen demand and total dissolved solids along the alluvial perimeter. Thus, urban sewage becomes a source of water recharge with potential to be reused. We concluded that the utilization of water from this type of aquifer, which has been intensified in recent dry years, can be established in a safe and sustainable way. However, a strict monitoring plan for controlling recharge groundwater levels is highly necessary. Further studies in this direction should lead to a model of adequate use of this system, which can be reproduced in the Brazilian semi-arid region.

Limits and conditions for the exploitation of alluvial aquifers in the Brazilian semi-arid region

Easily exploitable aquifers are formed along river beds in the Brazilian semi-arid region and present characteristics that enable the construction of underground dams. The estimate of the potential effective exploitation of these aquifers must take into account the pumping limits of the wells, the upstream groundwater inflows and the flows to downstream reaches and through the underground dam, whose reduction influences the downstream supply. The current research presents a real case study about an aquifer reach, with underground dam and wells, which was analyzed through computational model. We simulated the groundwater flow patterns according to different exploitation scenarios and found that there should be water extraction limitations to assure the required downstream flows. The limitations can be minimized through appropriate well locations and exploitation regimes, as well as through the implementation of underground dams. The definition of these measures becomes possible through the sound use of computational simulation, but their effective implementation will depend on negotiations among users at the basin scale, so that appropriate water permits can be issued.

GERENCIAMENTO DA ÁGUA SUPERFICIAL NO PERÍMETRO IRRIGADO DE SUMÉ-PB USANDO GIS-MCDA

GERENCIAMENTO DA AGUA SUPERFICIAL NO PERIMETRO IRRIGADO DE SUME-PB USANDO GIS-MCDA SUENIO ANDERSON FELICIANO DA SILVA ALVES 1 ; IANA ALEXANDRA ALVES RUFINO 2 E JANIRO COSTA REGO 3 1 Mestrando do Programa de Pos-graduacao em Engenharia Civil e Ambiental, Universidade Federal de Campina Grande – UFCG, Rua Aprigio Veloso, 882 - Universitario, Campina Grande - PB, Brasil, sueniof@gmail.com 2 Professor Associado da Unidade Academica de Engenharia Civil – CTRN, Universidade Federal de Campina Grande – UFCG, Rua Aprigio Veloso, 882 - Universitario, Campina Grande - PB, Brasil, iana.alexandra@ufcg.edu.br 3 Professor Associado da Unidade Academica de Engenharia Civil – CTRN, Universidade Federal de Campina Grande – UFCG, Rua Aprigio Veloso, 882 - Universitario, Campina Grande - PB, Brasil, janiro_rego@yahoo.com.br 1 RESUMO Este trabalho tem por objetivo utilizar uma Analise de Decisao Multicriterial em um Sistema de Informacao Geografica ( GIS-MCDA ) para encontrar alternativas no que concerne ao gerenciamento e uso da agua advinda de um reservatorio (barragem de Sume) no perimetro irrigado de Sume-PB. Para tanto, utilizou-se criterios tecnicos, economicos e ambientais para auxiliar na tomada de decisao em uma metodologia de Analise Hierarquica (AHP). A partir de um diagnostico da agua superficial sao observadas as possibilidades de irrigacao, tendo em vista a adequada qualidade quimica e microbiologica da agua do reservatorio e a sua disponibilidade. Com base nas restricoes e na modelagem espacial adotada sao elaboradas duas alternativas e, respectivamente, dois cenarios. A Alternativa I evidenciada pela preferencia ao criterio economico aponta uma area de 60 hectares inadequados e, consequentemente, a criacao de um cenario com irrigacao de 118 hectares distribuidos no decorrer do perimetro. A Alternativa II que estabelece preferencia ao criterio tecnico, inviabiliza a irrigacao em aproximadamente 167 hectares, com um cenario apresentando uma irrigacao de 112 hectares localizados proximos ao reservatorio. Palavras-chave: analise multicriterio, tomada de decisao, recursos hidricos. ALVES, S. A. F. da S.; RUFINO, I. A. A.; REGO, J. C. MANAGEMENT OF SURFACE WATER IN THE IRRIGATED PERIMETER SUME-PB USING GIS-MCDA 2 ABSTRACT This work presents a GIS-based Multiple-Criteria Decision Analysis (GIS-MCDA) for helping on water management in an irrigated area. The main water source is a reservoir called “Sume” (Sume Dam). Technical, environmental and economic criteria are used for a better decision-making process. The Analytic Hierarchical Process (AHP) is the methodology approach. Irrigation possibilities are considered based on an initial diagnosis about the surface water available. Chemical and microbiological quality are analyzed in order to obtain a suitable water for each irrigated lot. There are some restrictions established by the spatial modelling, and the results shows two alternatives and two scenarios. First, when the economical criterion is the priority, the model shows that an area of about 60 hectares is not suitable. For the second alternative, when the technical criterion is the priority, a huge area is showed as not suitable (about 167 hectares). In the latter scenario, only areas close to the reservoir should be irrigated. Keywords: multiple-criteria analysis, GIS, water resources.

Rule curve for seasonal increasing of water concessions in reservoirs with low regularized discharges

Regions with high hydrological variability are usually supplied by reservoirs that regularize discharges inter-annually, with low discharge of regularization, seasonally subject to large overflow and evaporation losses in their periods of high water levels. The Brazilian semiarid is one of such regions. This work looks at the possibility of using water that would be evaporated and/or spilled, in regions with such characteristics, to supply demands that would not be otherwise provided by the maximum legally allowed withdrawal discharge. The proposed method was applied to the operation of a large reservoir, located in the semiarid region of Brazil. Through simulation of the water budget and optimization, a rule curve was developed for reservoir operation for achieving the maximum exploitable reservoir withdrawal in rainy periods. The results show that it is possible to use the excess water in periods of large inflows with no damage to water supply during dry periods.