16,970 research outputs found

    Optimal Exploitation of Groundwater and the Potential for a Tradable Permit System in Irrigated Agriculture

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    A great challenge facing future agricultural water policy is to explore the potential for transition from the current myopic competitive (common) exploitation of groundwater resources to a long-term efficient and sustainable allocation. A number of economic and/or command and control instruments can be used by the relevant water authority in order to deal with the economic and environmental problems generated by competitive exploitation. However, according to previous experience in both developed and developing countries, tradable permits seem as one of the most effective and efficient instruments, especially under conditions of limited water availability. On this account, the aim of the current study is to explore the feasibility and implementation of a tradable permit system in irrigated agriculture. To this end, two distinct optimization models are applied and compared: (a) an individual farmer’s model (representing the myopic non-cooperative exploitation of groundwater) and (b) a social planner’s model (representing the cooperative and sustainable allocation). The deviation of their results shows the rationale for using a tradable permit system, while the final allocation of the social planner’s model, solved as an optimal control problem that maximizes the social welfare under specific water policy objectives, denotes the equilibrium state of this system. The two models are then applied in a typical rural area of Greece where groundwater is the only source of irrigated agriculture. The derived time paths for water consumption and water availability illustrate the significant environmental benefits from the future implementation of a tradable permit system.Tradable Water Permits, Sustainable Water Use, Irrigated Agriculture

    ASSESSING ECONOMIC AND TECHNICAL IMPACTS OF NON EXPECTED WEATHER EVENTS ON FRENCH SUCKLER COW FARMS DYNAMICS: A DYNAMIC RECURSIVE FARM MODEL

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    Weather variability can threaten French suckler cow farms which rely on rather extensive forage production. However, flexibility of the production system can help farmer to face crop production shocks. This study aims at assessing how crop yield shocks impact on farms outcomes when adaptive capacity is taken into account. Our objectives are to develop a dynamic model which enables us 1) to predict the optimal mix of production adjustments to face crop yield shocks, 2) to quantify how far the system moves from the equilibrium and how long it takes to return and 3) to measure impact of shocks on economic results when adaptive capacity is taken into account. An original dynamic recursive bio-economic farm model integrating detailed technical and biological constraints and coupled with biological sub-models has been built and calibrated to represent an average farm producing charolais finished animals. Crop yield shocks of intensities ranging between -60% and +60% of their average values are simulated in between average years. A preference for maintaining animal sales and animal live weight at the expense of crop products trade balance is found. Thought, when intensities of shocks get higher, forced sales and important variations of the area of pasture cut are observed. Essential of loss (or gain) of net profit is felt the year of the shock but can be remnant for several years. In addition, gains for good years do not totally compensate loss of symmetric bad ones. Consequently, farms capacity to face risk could be weaken over time. Minimum consumption needs, probability distribution of shocks and successions or combinations of shocks would have thought to be taken into account to assess real capacity of farms to maintain over time.livestock farm model, dynamic recursive model, crop yield variability, Livestock Production/Industries,

    Modeling water resources management at the basin level: review and future directions

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    Water quality / Water resources development / Agricultural production / River basin development / Mathematical models / Simulation models / Water allocation / Policy / Economic aspects / Hydrology / Reservoir operation / Groundwater management / Drainage / Conjunctive use / Surface water / GIS / Decision support systems / Optimization methods / Water supply

    Seasonality in cocoa spot and forward markets: empirical evidence

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    This paper first describes the main features of supply and demand in cocoa spot markets. A state- variable model is proposed to describe the random evolution of cocoa forward curves over time, which essentially adapts to agricultural commodities, introduced by Borovkova and Geman (2006) for energy. In contrast to most of the literature on the subject, the first state variable is not the spot price, as it combines seasonal and stochastic features and may not be observable, instead, the average value of all liquid futures contracts is a quantity devoid of seasonality and conveys a robust representation of the forward curve level. The second state variable is a quantity analogous to the stochastic convenience yield, which accounts for the random changes in the shape of the forward curve. We conduct estimation procedures for the cocoa market over the period of 1980 to 2009 and exhibit an interesting result on cocoa seasonality as well as an extension of the Samuelson effect

    Terrestrial applications: An intelligent Earth-sensing information system

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    For Abstract see A82-2214

    Bio-inspired optimization in integrated river basin management

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    Water resources worldwide are facing severe challenges in terms of quality and quantity. It is essential to conserve, manage, and optimize water resources and their quality through integrated water resources management (IWRM). IWRM is an interdisciplinary field that works on multiple levels to maximize the socio-economic and ecological benefits of water resources. Since this is directly influenced by the river’s ecological health, the point of interest should start at the basin-level. The main objective of this study is to evaluate the application of bio-inspired optimization techniques in integrated river basin management (IRBM). This study demonstrates the application of versatile, flexible and yet simple metaheuristic bio-inspired algorithms in IRBM. In a novel approach, bio-inspired optimization algorithms Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO) are used to spatially distribute mitigation measures within a basin to reduce long-term annual mean total nitrogen (TN) concentration at the outlet of the basin. The Upper Fuhse river basin developed in the hydrological model, Hydrological Predictions for the Environment (HYPE), is used as a case study. ACO and PSO are coupled with the HYPE model to distribute a set of measures and compute the resulting TN reduction. The algorithms spatially distribute nine crop and subbasin-level mitigation measures under four categories. Both algorithms can successfully yield a discrete combination of measures to reduce long-term annual mean TN concentration. They achieved an 18.65% reduction, and their performance was on par with each other. This study has established the applicability of these bio-inspired optimization algorithms in successfully distributing the TN mitigation measures within the river basin. Stakeholder involvement is a crucial aspect of IRBM. It ensures that researchers and policymakers are aware of the ground reality through large amounts of information collected from the stakeholder. Including stakeholders in policy planning and decision-making legitimizes the decisions and eases their implementation. Therefore, a socio-hydrological framework is developed and tested in the Larqui river basin, Chile, based on a field survey to explore the conditions under which the farmers would implement or extend the width of vegetative filter strips (VFS) to prevent soil erosion. The framework consists of a behavioral, social model (extended Theory of Planned Behavior, TPB) and an agent-based model (developed in NetLogo) coupled with the results from the vegetative filter model (Vegetative Filter Strip Modeling System, VFSMOD-W). The results showed that the ABM corroborates with the survey results and the farmers are willing to extend the width of VFS as long as their utility stays positive. This framework can be used to develop tailor-made policies for river basins based on the conditions of the river basins and the stakeholders' requirements to motivate them to adopt sustainable practices. It is vital to assess whether the proposed management plans achieve the expected results for the river basin and if the stakeholders will accept and implement them. The assessment via simulation tools ensures effective implementation and realization of the target stipulated by the decision-makers. In this regard, this dissertation introduces the application of bio-inspired optimization techniques in the field of IRBM. The successful discrete combinatorial optimization in terms of the spatial distribution of mitigation measures by ACO and PSO and the novel socio-hydrological framework using ABM prove the forte and diverse applicability of bio-inspired optimization algorithms
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