Antonio Lanna

A economia dos recursos hídricos: os desafios da alocação eficiente de um recurso (cada vez mais) escasso

O artigo apresenta e analisa os cenarios prospectivos de recursos hidricos com base nos quais foram estabelecidas as diretrizes, as metas e os programas do Plano Nacional de Recursos Hidricos (PNRH). Em razao das informacoes, sao analisadas as perspectivas futuras dos quatro setores usuarios de agua com maiores dinâmicas e possibilidades de conflito: agricultura irrigada, geracao de energia, navegacao e saneamento basico. Uma questao que nao pode ser desconsiderada e a das mudancas climaticas e como poderao afetar as disponibilidades e os usos da agua. Dessa analise, algumas conclusoes e recomendacoes vao ser enunciadas, tendo por objetivo a antecipacao do futuro e o preparo dos agentes publicos, privados e do terceiro setor para essa tarefa de promocao do uso racional da agua, tendo em vista o desenvolvimento sustentavel. Ou, como dizem economistas, de alocacao otima de um recurso escasso.

Management of Navigation in the Jacui River

ABSTRACT Management of a river system is usually a difficult task due to conflicting water use purposes. The Jacui river (southern Brazil) has a drainage area of 70000 km2, with hydroelectric plants in its upper reach and three navigation dams in the middle and lower reaches. The former dams are used to meet peak power demand, producing great flow variations during weekdays and volume reduction during weekends. The navigation dams do not allow year round navigation due to sediment deposition, low-flow and upstream flow fluctuation. A hydrodynamic model was used to study flow routing, to test operation rules for the navigation dams and to forecast the levels in real time. In this paper, the calibration of the model and the operational criteria to be applied to each of the navigation dams during low-flow periods are presented. The model was calibrated with two recorded events showing maximum errors compatible with the river navigation requirements. Dam operation simulations showed that with the help of the ...

MARGINAL EXPECTATIONS IN RESERVOIR OPERATION

An algorithm is developed for a problem of optimal reservoir operation when future inflows are uncertain. The approach to the algorithm is similar to Stochastic Dynamic Programming. A stopping-rule for searching for the optimal release in each time interval is imbedded in the algorithm. Furthermore, a systematic search procedure for the Optimal release is additionally provided when the economic law of diminishing returns applies to reservoir operation These characteristics of the algorithm are believed to enhance its computational efficiency as compared to Stochastic Dynamic Programming. Computational details and application tests are presented for purposes of comparisons.

Water and Economy

This paper addresses one of the important issues that face water against its economic aspects: the use of economic instruments to manage water resources. First, historic and conceptual issues are considered. In a second part, the Brazilian water resource legislation is analyzed. In a third part, the water user pays principles (UPP) and water polluter pays principles (PPP) are considered, with their contributions towards adoption of economic instruments for water resources management. Finally, a comparison between these principles and the reality of the current Brazilian water resources management is presented, showing that there is still much to move.

Análise Econômica de uma Alternativa de Baixo Custo para a Irrigação de Pequenas Propriedades em Regiões Acidentadas

This study deals with a set of methods for classifying land regarding its potential use in coop irrigation with low operational and investment costs applicable in regions with an irregular relief. The use of a Geographic Information System and Remote Sensing techniques together with soil data and classification, hydrological, agricultural and economic information, allowed the identification and classification of areas suitable for irrigation techniques based on gravity flow at the scarp of the Rio Grande do Sul Plateau, occupied by a large number of agricultural smallholdings. The model was applied to the Santa Cruz do Sul region in Rio Grande do Sul, Brazil, superposing thematic maps of water resources, soil production potentials, relief and native forest cover. In this 759 km2 area, comprising the municipality of Santa Cruz do Sul, an area totaling 512.45 km2 suitable for the use of irrigation techniques based on gravity flow, was identified; 9% of this area presents conditions for economically feasible irrigation projects with low investment costs. In two of them experimental tests were applied for production cost and benefit analysis, and information collected which allowed the determination of areas where irrigation is economically feasible. Key-words: Low-cost irrigation, rural smallholdings.

Um Modelo de Seguro Agrícola para a Gestão de Riscos na Agricultura em Sequeiro

One of the public policy objectives in agriculture-dependent countries is to provide decision-making criteria to cope with risk and uncertainty. In order to do so, it is necessary to evaluate how much “cost of uncertainty” society is willing to pay, or to reduce it using risk transfer instruments such as Insurance. Crop insurance provides protection against reduced income for the farmer as a result of low productivity, caused by critical hydrological events, or other adverse natural events, or the decrease in market prices. This paper deals with the first of these causes (it does not take into account the variability in market prices) through a capitalization model with the following characteristics: i) financial sustainability, by means of an annuity to be paid by the beneficiaries, without a need for the systematic use of public resources and ii) social protection, through a minimum income warranty to the farmers The model is tested on agricultural activity in the Argentine Chaco. Key-words: crop insurance; risk; cost.