Carlos de Oliveira Galvão

Influência das atividades antrópicas na qualidade das águas da bacia hidrográfica do Rio Salitre

Avaliar os impactos das atividades agricolas sobre a qualidade das aguas da bacia hidrografica do Rio Salitre, foi o objetivo deste estudo. Para isto, 92 fontes hidricas localizadas em areas irrigadas ou nao, foram analisadas nos periodos de chuva e sem chuva de 2001, avaliando-se os principais indicadores para consumo humano e irrigacao. A partir dos resultados, observou-se a influencia da irrigacao sobre a qualidade das aguas, ocorrendo aumentos significativos na condutividade eletrica da agua e no extrato de saturacao dos solos; esses aumentos indicam baixa eficiencia dos sistemas de producao, constatando-se que, em media, 35 e 77% das fontes hidricas foram classificadas como C3 e C4, respectivamente; tambem, que 78% dessas fontes estao localizadas sob formacoes calcarias, cuja influencia sobre a qualidade das aguas pode ser notada pelos elevados teores de solidos dissolvidos totais (SDT = 7.940,0; 5.060,0 mg L-1), relacao de adsorcao de sodio (RAS = 25,27; 6,71 mmol L-1)1/2), dureza total (DT = 2.999,6; 2.940,0 mg L-1) e percentual de cloretos (ClP = 97,51; 94,59%), entre outros, limitando sua utilizacao; tais resultados apontam para a necessidade de medidas de preservacao e de conservacao dos recursos hidricos e dos solos desta bacia hidrografica para permitir a sustentabilidade ambiental.

Fostering collaboration to better manage water resources

Good water management is literally vital for the arid and semi‐arid regions of the planet. Yet good water management requires multidisciplinary expertise, since one must consider climatic, hydrological, economical and social aspects to make balanced decisions on water usage. We here present SegHidro, a Grid portal designed to foster scientific, technical and operational collaboration to improve water resources management. The portal targets researchers and decision makers, enabling them to execute and couple their computational models in a workflow. The portal provides a framework which allows seamless integration of the models, meaning that each phase of the flow may be executed by a different expert and that the resulting data are shared among other portal users. Due to the nature of these applications and the need to execute many prospective scenarios, their execution requires high computing power. However, we go beyond providing high‐performance computational Grid capabilities. We also enable people to complement each others expertise in understanding the trade‐offs in the water allocation decisions. The SegHidro portal is about sharing: human expertise, data and computing power. Copyright

Uso de análise multivariada na classificação das fontes hídricas subterrâneas da bacia hidrográfica do Salitre

Este estudo teve por objetivo identificar as variaveis responsaveis pela maior variabilidade da qualidade das aguas subterrâneas da bacia hidrografica do Rio Salitre - BA, e detectar as fontes que apresentam caracteristicas semelhantes, visando a subsidiar medidas de monitoramento e gestao da qualidade das aguas da bacia. Para isso, foram utilizadas tecnicas de analise multivariada referente a analise fatorial em componentes principais e de agrupamento. A analise fatorial permitiu agrupar as variaveis em tres fatores principais que explicaram 86,99%; 72,08% e 68,33% da variância total acumulada em 1984 e 2001, nos periodos de chuvas e sem chuvas, respectivamente. As variaveis priorizadas estao relacionadas com a salinidade das aguas. Assim, medidas de melhoria da qualidade das aguas nessa bacia devem necessariamente priorizar a salinidade das aguas, a qual esta associada a sua geologia. As fontes hidricas foram classificadas em tres classes, de forma que C1 agrupou as fontes de melhor qualidade das aguas, totalizando 25,0%; 74,3% e 61,7% das fontes hidricas, cujos valores medios dos solidos dissolvidos totais variaram de 199,00 mg L-1, em 1984, para 724,86 e 650,34 mg L-1, em 2001, respectivamente. A maioria das fontes enquadradas como C1, em 1984, permaneceu em 2001, decorridos 16 anos.

Adaptation to Climate Change: Institutional Analysis

There are many challenges for water management under climate change. Institutional capacity for enabling adaptation is one of those challenges, which have to consider uncertainties, participatory processes, and monitoring. Elinor Ostrom, a Nobel winner, produced many relevant contributions to understanding institutional governance. Her work pointed to requirements of adaptive governance, institutional design principles for local common pool resources systems, and social-ecological framework analysis. Recently, Ostrom’s institutional principles have been extended for the governance of adaptation to climate change in the water sector. Adaptation in water sector is a continuous process of learning. Drought management in the present and past is also a way of learning considering experiences on institutions dealing with this challenge. This chapter illustrates how Ostrom’s principles, in the context of a drought management experience in Brazil, might provide a continuous way for assessing if institutions are capable to play their roles in the process of adaptation to climate variability and change.

A Science Gateway for Biodiversity and Climate Change Research.

Climate and biodiversity systems are closely interlaced across a wide range of scales. To better understand the mutual interaction between climate change and biodiversity there is a strong need for multidisciplinary skills, tools and a large variety of heterogeneous, distributed data sources. In this regard, the EUBrazilCloudConnect project provides a user-centric research environment built on top of a federated cloud infrastructure across Europe and Brazil to serve scientific needs. One of the test cases implemented in this project focuses on climate change and biodiversity research. The BioClimate is the Science Gateway of the use case. It aims at providing the end-users with a highly integrated environment, addressing mainly data analytics requirements. This paper presents a complete overview about BioClimate and the scientific environment delivered to the user community at the end of the project.

Sub-hourly rainfall patterns by hyetograph type under distinct climate conditions in Northeast of Brazil: a comparative inference of their key properties

The lack of process-based classification procedures may lead to unrealistic hyetograph design due to complex oscillation of rainfall depths when assimilated at high temporal resolutions. Four consecutive years of sub-hourly rainfall data were assimilated in three study areas (Guaraíra, GEB, São João do Cariri, CEB, and Aiuaba, AEB) under distinct climates (very hot semi-arid and tropical wet). This study aimed to define rainfall events (for Minimum Inter-event Time, MIT, and Minimum Rainfall Depth, MRD, equal to 30 min and 1.016 mm, respectively), classify their hyetograph types (rectangular, R, unimodal with left-skewed, UL, right-skewed, UR, and centred peaks, UC, bimodal, B, and shapeless, SL), and compare their key rainfall properties (frequency, duration, depth, rate and peak). A rain pulse aggregation process allowed for reshaping SL-events for six different time spans varying from 2 to 30 min. The results revealed that the coastal area held predominantly R-events (64% events and 49% rainfall depth), in western semi-arid prevailed UL-events (57% events and 63% rainfall depth), whereas in eastern semi-arid mostly were R-events (61% events and 30% rainfall depth) similar to coastal area. It is concluded that each cloud formation type had important effects on hyetograph properties, differentiating them even within the same climate.

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.

Climate Change Impacts and Water Resource Management and Planning

Sustainable water resource planning for climate change is a process of assessing risks related to climate change, evaluating and selecting strategies that are based on current hydrological knowledge, using climate models, monitoring existing conditions, and providing guidelines for adaptation and the optimal use of available water resources for the benefit of the society. This chapter provides a road map to show how climate projections can be incorporated into water management decisions. In particular, it explores which projections to use and how to relate them to planning assumptions on water supplies, water demands, and operating restraints, and it also provides useful recommendations on how to improve water resource planning and management and on how to proceed with effective water policy actions considering climate variability and change.

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.

Dimensionamento de sistema de microirrigação através de programação não linear considerando-se diferentes demandas hídricas

In this work the optimum microsprinkler system design is analyzed through optimization model using non linear programming, with the objective of minimizing operational and investment costs, for three sceneries of the water demand in two localities of the Northeast region of Brazil: Iguatu, Ceara State, with annual and monthly water balances, and Joao Pessoa, Paraiba State, with monthly water balance. The model has as decision variables: the lengths of the pipe sections with their respective diameters, the daily irrigation total time, the emission uniformity, the irrigation frequency and the emitter mean operation pressure. The results evidenced that in semi-arid climate areas, as Iguatu, there are not important differences in the design system with the demands obtained through the annual or monthly water balances. The investment cost was not affected by the demands, but just the operational and total system costs. Regions with smaller daily and annual water requirement, as Joao Pessoa, allow larger number of operational units of the system and, therefore, larger reduction of the investment cost. However, for same number of the subunit and operational units the water demands differences do not affect the design. The maximum daily water demand of the crop has larger effect on the hydraulic system than the annual water demand. The system with optimum design depends on the combined analysis of the subunit number and of operational units of the system and the energy cost should not be ignored.