Ticiana Marinho de Carvalho Studart

An Historical Perspective on the Administration of Water in Brazil

Abstract This article focuses on two instruments of water resources management—charging for water and reallocation of water use through a water market. Charging for water in nature has been practiced for centuries in some cases. On the other hand, a culture of free access to water was dominant in most countries during ancient times. An historical review of the charging of water and its administration is presented. The article covers the time of ancient Rome to the present. A current example is the model practiced in the semi-arid region of Ceará State in northeast Brazil. Regarding water use reallocation by a water market, as an alternative to improve water efficiency, the experience presented comes from the south of Ceará State one century ago. Based on past experience, the article then presents a model to implement a water market bounded in space to an irrigation district, and in time to periods of water deficit in reservoirs. Six prerequisites of market-based transfers of water are analyzed, and it is shown that in the proposed model they can be addressed.

Conflitos por águas e alocação negociada: o caso do vale dos Carás no Ceará

The paper describes a water conflict for using the water regulated by the Thomas Osterne and Manoel reservoirs in Caras river basin in southern part of Ceara State. Along the river, farmers have built small dams to withdraw waters released in the river from the reservoirs. In times of droughts, the conflict settled in due to the retention of water in upstream that prevented it came to users of downstream. The article also describes the Ceara States institutional model and the way it deals with water conflicts. It is analyzed the practice of negotiating the water allocation as a strategy for conflict mediation. The main actors involved in conflict and its mediation were: users, technical water managers, prosecutors, political, and environmental institutions. As a result, it has been achieved, peacefully, the removal of earths dams that interfered in the free flow of water.

Reservoir yield intercomparison of large dams in Jaguaribe Basin-CE in climate change scenarios

Climate changes can have different impacts on water resources. Strategies to adapt to climate changes depend on impact studies. In this context, this study aimed to estimate the impact that changes in precipitation, projected by Global Circulation Models (GCMs) in the fifth report by the Intergovernmental Panel on Climate Change (IPCC-AR5) may cause on reservoir yield (Q90) of large reservoirs (Castanhão and Banabuiú), located in the Jaguaribe River Basin, Ceará. The rainfall data are from 20 GCMs using two greenhouse gas scenarios (RCP4.5 and RCP8.5). The precipitation projections were used as input data for the rainfall-runoff model (SMAP) and, after the reservoirs’ inflow generation, the reservoir yields were simulated in the AcquaNet model, for the time periods of 2040-2069 and 2070-2099. The results were analyzed and presented a great divergence, in sign (increase or decrease) and in the magnitude of change of Q90. However, most Q90 projections indicated reduction in both reservoirs, for the two periods, especially at the end of the 21th century.

Calculation method for charging water on shrimp farming

The increase of global water demand has stimulated the application of water charging to seek its rational use. However, the establishment of the water tariff for a certain use is not an easy task, given that this tariff must have an elevated value, sufficient to encourage the rational use, but not so elevated, in a manner that compromises or prevents the development of production activities. The present study aimed to evaluate different water tariff values proposed and applied to the shrimp farming industry in Ceara, from 2003 to 2016, and analyze the sensitivity of the industry to these values. The analyses considered the productive performance of the shrimp farming observed by the producers, production costs for the activity, and incomes earned by the producers in 2008. The present study demonstrated that the only tariff value that makes the sector financially attractive is R

Trade-off between reservoir yield and evaporation losses as a function of lake morphology in semi-arid Brazil

1.00/1,000m3, a lower value than the one previously proposed by the state of Ceara (R

Reservoir Yield Vulnerability Under Global Change

31.20/1,000m3), which was reduced in the following years. In this context, a model was developed to fix tariffs for shrimp farming, which considers the payment capacity of the entrepreneur and the production costs to cultivate shrimp.

From Drought to Water Security: Brazilian Experiences and Challenges

This study investigates the relationships between yield and evaporation as a function of lake morphology in semi-arid Brazil. First, a new methodology was proposed to classify the morphology of 40 reservoirs in the Ceará State, with storage capacities ranging from approximately 5 to 4500 hm3. Then, Monte Carlo simulations were conducted to study the effect of reservoir morphology (including real and simplified conical forms) on the water storage process at different reliability levels. The reservoirs were categorized as convex (60.0%), slightly convex (27.5%) or linear (12.5%). When the conical approximation was used instead of the real lake form, a trade-off occurred between reservoir yield and evaporation losses, with different trends for the convex, slightly convex and linear reservoirs. Using the conical approximation, the water yield prediction errors reached approximately 5% of the mean annual inflow, which is negligible for large reservoirs. However, for smaller reservoirs, this error became important. Therefore, this paper presents a new procedure for correcting the yield-evaporation relationships that were obtained by assuming a conical approximation rather than the real reservoir morphology. The combination of this correction with the Regulation Triangle Diagram is useful for rapidly and objectively predicting reservoir yield and evaporation losses in semi-arid environments.

Flood damping by reservoirs: proposition of a graphical parametric method

There is no scientific consensus on how climate changes will modify the hydrological cycle. Climate models still need to be improved in order to better evaluate accurately these changes. Predictions of regional effects on the hydrological cycle vary significantly among different models. Nevertheless, there is a consensus on global precipitation and evaporation increase.

Regional envelope curves for the state of Ceará: a tool for verification of hydrological dam safety

Water security is a relevant concept for public well-being and sustainable development. The word ‘security’ often refers to the idea of predictability, control, and assurance. These are relevant concepts in our changing world. Change involves social and natural processes on a planetary scale that shape and transform local realities. In this framework, the concept of water security must be understood as dialectically related to the concept of risk. In the past few years, the concept of water security has been increasingly disseminated in Brazil, owing to severe droughts that have struck several of the country’s regions. Between 2013 and 2015, South-East Brazil experienced the worst drought ever recorded there. In North-East Brazil, a similar episode began in 2011 and still persists in 2017. The impacts of these events, which are associated with climate risk and societal adaptation, have placed the issue of water security on the Brazilian political agenda, but decision makers’ conceptual approach is still fragile. This chapter describes the Brazilian experience with water security that emerged from the water crises in two large metropolitan regions: Sao Paulo, in Sao Paulo State, the economic power of the wet South-East Region; and Fortaleza, in Ceara State, a semi-arid part of the North-East Region that has dealt with the impacts of drought throughout its history. The respective droughts are described, as well as the water security strategies that were adopted during each of those crises, the lessons learned, and challenges for the future.

ERRO TIPO I E “PODER” DE TESTES DE ADERÊNCIA PARA POSTOS PLUVIOMÉTRICOS NO CEARÁ

Flood reduction constitutes an important characteristic of surface reservoir design. Thus, to ensure that minimum safety standards are met, the Safety Dams Act was approved in 2010. Many multipurpose surface reservoirs are aging and getting out of the current technical standards. In Ceará State, Brazil, there are several dams built for many decades, with spillways sized by empirical formulae which are currently outdated. This article contributes to improve the understanding of the morphological and hydrological factors involved in the process of damping floods in reservoirs and the development of a simple application method that estimates the damping, from such factors. To do so, hydrological simulations of several scenarios representative of reservoir and hydrographic basins configurations were performed. As a result, the impact of each parameter on flood damping was determined. A graphical method was proposed in which all the morphological parameters of the basin and the reservoir were aggregated into a single dimensionless parameter the Reservoir Damping Index (Φ). With the value of Φ calculated, it is possible to estimate the damping capacity of the reservoir. This method can be used for the design of new reservoirs or for the verification of reservoir spillways already constructed with other methodologies.