Márcia Maria Guedes Alcoforado de Moraes

Joint Water Quantity-Quality Management in a Biofuel Production Area—Integrated Economic-Hydrologic Modeling Analysis

Water management in the Pirapama River Basin in northeastern Brazil is affected by both water quantity and water quality constraints. The region is known for significant sugarcane-based ethanol production—which is the key to the Brazilian economy and expected to grow dramatically under recent changes in climate and energy policies. Sugarcane production in the region goes hand in hand with controlled fertirrigation practices with potentially significant adverse impacts on the environment. To assess sustainable water allocation in the basin, an integrated hydrologic-economic basin model is adapted to study both water quantity and quality aspects. The model results show that incorporating water quality aspects into water allocation decisions leads to a substantial reduction in application of vinasse to sugarcane fields. Embedding highly nonlinear water quality constraints in a basin optimization model is demonstrated to be an effective tool to address the water management problems in rapidly developing biofuel areas of Brazil and elsewhere. DOI: 10.1061/ASCEWR.1943-5452.0000049 CE Database subject headings: Water quality; River basins; Hydrologic models; Optimization; Biomass; Economic factors; Brazil. Author keywords: Water quality; River-basin management; Integrated economic-hydrologic modeling; Nonlinear optimization; Biofuel. Background The Pirapama River Basin is located in the metropolitan regions of Recife—locally known as Regiao Metropolitana do Recife RMR and the Pernambuco Mata in northeastern Brazil see Fig. 1. It covers an area of about 600 km 2 and the approximate length of its main waterway is 80 km. The Pirapama is the most important water source for the city of Recife, capital of the state of Pernambuco. The region is affected by a lack of adequate water and sewage treatment resulting in high levels of water pollution during dry spells Ribeiro 2000. Throughout the length of the river most currently monitored water quality standards cannot be

Bioenergy Development Policy and Practice Must Recognize Potential Hydrologic Impacts: Lessons from the Americas

Large-scale bioenergy production will affect the hydrologic cycle in multiple ways, including changes in canopy interception, evapotranspiration, infiltration, and the quantity and quality of surface runoff and groundwater recharge. As such, the water footprints of bioenergy sources vary significantly by type of feedstock, soil characteristics, cultivation practices, and hydro-climatic regime. Furthermore, water management implications of bioenergy production depend on existing land use, relative water availability, and competing water uses at a watershed scale. This paper reviews previous research on the water resource impacts of bioenergy production—from plot-scale hydrologic and nutrient cycling impacts to watershed and regional scale hydro-economic systems relationships. Primary gaps in knowledge that hinder policy development for integrated management of water–bioenergy systems are highlighted. Four case studies in the Americas are analyzed to illustrate relevant spatial and temporal scales for impact assessment, along with unique aspects of biofuel production compared to other agroforestry systems, such as energy-related conflicts and tradeoffs. Based on the case studies, the potential benefits of integrated resource management are assessed, as is the need for further case-specific research.

Curvas de demanda pelos recursos hídricos dos principais usos consuntivos no submédio da bacia do Rio São Francisco

A regiao do submedio da bacia do Rio Sao Francisco tem uma variedade deusos, com alguns conflitos ja estabelecidos. Curvas de demanda da agua saoimportantes para identificar o valor economico dado ao recurso hidrico pelousuario diante de diferentes quantidades disponibilizadas. O conhecimento detais curvas deve auxiliar no estabelecimento de politicas que criem incentivosadequados ao uso eficiente do recurso e evitem sua sobre‑exploracao.Este trabalho apresenta curvas de demanda pelos recursos hidricos estimadaspara os usuarios da agricultura irrigada e para o abastecimento humanousando o metodo de programacao matematica positiva e expansao de ponto.Os resultados para a agricultura irrigada nos dois metodos mostraram que omix de culturas e o fator mais relevante na disposicao a pagar dos usuarios pelorecurso hidrico e que, para o abastecimento humano, os valores economicosem relacao ao mesmo grau de disponibilidade hidrica foram mais elevadosem comparacao com a irrigacao.

The impact of global change on economic values of water for Public Irrigation Schemes at the São Francisco River Basin in Brazil

Economic values of water for the main Public Irrigation Schemes in the sub-middle region of the São Francisco River Basin, in northeastern Brazil, are determined in this study using an integration of a global agro-economic land and water use (MAgPIE) with a local economic model (Positive Mathematical Programming). As in the latter, the water values depend on the crops grown, and as Brazilian agriculture is strongly influenced by the global market, we used a regionalized version of the global model adapted to the region in order to simulate the crop land use, which is in turn determined by changes in global demand, trade barriers, and climate. The allocation of sugarcane and fruit crops projected with climate change by the global model, showed an impact on the average yields and on the water costs in the main schemes resulting in changes in the water values locally. The economic values for all schemes in the baseline year were higher than the water prices established for agricultural use in the basin. In the future, these water values will be higher in all the schemes. The highest water values currently and in the future were identified in municipalities with a significant proportion of area growing irrigated sugarcane. Being aware of current water values of each user in a baseline year and in a projected future under global climate and socioeconomic changes, decision makers should improve water allocation policies at local scale, in order to avoid conflicts and unsustainable development in the future.

Economic water management decisions: trade-offs between conflicting objectives in the sub-middle region of the São Francisco watershed

Hydro-economic models can measure the economic effects of different reservoir operating rules, environmental restrictions, maintenance of ecosystems, technical constraints, institutional constraints, land use change, and climate change. To determine the optimal economic water allocation, for its main uses in the sub-middle of the São Francisco River Basin, a hydro-economic optimization model was developed and applied. Demand curves were used rather than fixed requirements for water resources. The results show that operation rules of reservoirs and institutional constraints, such as priorities for human consumption, have high impacts on costs and benefits of the principal economic uses in the study area. Especially, costs of environmental demands, like minimum ecological river flow, have high impacts on the water resource management. Scarcity costs of irrigation users associated with maintaining ecosystems and environmental constraints are particularly significant. The results from this study provide a better understanding of the water trade-offs for future policymaking and efficient water management. Policymaking for the water resources should consider the food-water-energy-environment nexus at a regional scale to minimize environmental and economic cost under water scarcity and land use change.

The legacy of large dams and their effects on the water-land nexus

Man-made river dams and reservoirs have increasingly been constructed to modify free-flowing rivers to benefit society through hydropower generation, irrigation, and other water supplies, navigation, and flood prevention. However, this ongoing global boom (Zarfl et al. 2015) also triggers harmful outcomes to local, directly affected stakeholder groups, and the environment. Particularly, profound social impacts of involuntary resettlement need alleviatingmeasures and room for remembrance. Restoring vital characteristics of aquatic ecosystems after artificial reservoir establishment, to any possible degree, may contribute to higher welfare and sustainability. Large reservoirs cause both particularly large positive and negative effects on society, the economy, and the environment. In Brazil, reservoirs were initially constructed for the primary purpose of hydroelectricity generation, to prevent flooding, and to provide irrigation capacities in the dryer parts of the country. However, an increasing number of users and usages have increased the pressure on stored and flowing water. Their requirements differ in terms of river discharge, water quality, and reservoir levels, most often reducing the options of the water users downstream. The resolution of conflicts over water allocation and management has been legally supported by the Brazilian Water Act since 1997, which introduced the paradigm of multiple and equally important water uses. Several of these water uses are closely linked to land-use practices, particularly irrigated agriculture. By law, domestic supply for the river basin’s residents sets a priority for water consumption during pronounced water scarcity. In terms of accessibility and water quality, water abstraction for domestic supply is being affected by water levels. Domestic water supply is also directly linked to water pollution through dilution of untreated wastewater in the river or reservoir. The intertwined and often divergent necessities and externalities of water and land use call for a coordinated management and governance approach to mitigate conflicts. Yet many of

Custos de Oportunidade para Alocação de Efluentes nas Áreas Plantadas de Cana na Bacia do Rio Pirapama

This paper identifies the opportunity costs in effluent allocation over sugarcane crop acres located more than 2Km away from the agroindustry plant JB, during the harvest season. The optimization problem described herein explains why these opportunity costs are usually missed. Actually, these costs derive from the marginal values associated to the decision-making variables concerning an economic benefit maximization problem resolved using the General Algebraic Modeling System (GAMS) and from the dual analysis of the linearized problem therein. Besides, different effluent transportation and effluent treatment cost coefficients were considered in simulating possible impacts and benefits regarding effluent allocation. This approach supports the optimal definition of charging and/or subsidizing schemes best suited to allocate effluents over sugarcane crops located farther away from hub agroindustry plants, not just for more disseminated productivity gains, but also for best compliance with river water quality constraints.