Analyzing the determinants of farmers' choice of adaptation methods and perceptions of climate change in the Nile Basin of Ethiopia:

"This study identifies the major methods used by farmers to adapt to climate change in the Nile Basin of Ethiopia, the factors that affect their choice of method, and the barriers to adaptation. The methods identified include use of different crop varieties, tree planting, soil conservation, early and late planting, and irrigation. Results from the discrete choice model employed indicate that the level of education, gender, age, and wealth of the head of household; access to extension and credit; information on climate, social capital, agroecological settings, and temperature all influence farmers' choices. The main barriers include lack of information on adaptation methods and financial constraints. Moreover, the analysis reveals that age of the household head, wealth, information on climate change, social capital, and agroecological settings have significant effects on farmers' perceptions of climate change." from authors' abstractAdaptation, Perception on climate change, Agriculture, Climate change, Nile Basin of Ethiopia,

Calibration and evaluation of a semi-distributed watershed model of Sub-Saharan Africa using GRACE data

International audienceIrrigation development is rapidly expanding inmostly rainfed Sub-Saharan Africa. This expansion underscoresthe need for a more comprehensive understandingof water resources beyond surface water. Gravity Recoveryand Climate Experiment (GRACE) satellites provide valuableinformation on spatio-temporal variability in water storage.The objective of this study was to calibrate and evaluatea semi-distributed regional-scale hydrologic model basedon the Soil and Water Assessment Tool (SWAT) code forbasins in Sub-Saharan Africa using seven-year (July 2002–April 2009) 10-day GRACE data and multi-site river dischargedata. The analysis was conducted in a multi-criteriaframework. In spite of the uncertainty arising from the tradeoffin optimising model parameters with respect to two noncommensurablecriteria defined for two fluxes, SWAT wasfound to perform well in simulating total water storage variabilityin most areas of Sub-Saharan Africa, which havesemi-arid and sub-humid climates, and that among variouswater storages represented in SWAT, water storage variationsin soil, vadose zone and groundwater are dominant. Thestudy also showed that the simulated total water storage variationstend to have less agreement with GRACE data in aridand equatorial humid regions, and model-based partitioningof total water storage variations into different water storagecompartments may be highly uncertain. Thus, future workwill be needed for model enhancement in these areas with inferiormodel fit and for uncertainty reduction in componentwiseestimation of water storage variations

Identifying Most Probable Negotiation Scenario in Bilateral Contracts with Reinforcement Learning

This paper proposes an adaptation of the Q-Learning reinforcement learning algorithm, for the identification of the most probable scenario that a player may face, under different contexts, when negotiating bilateral contracts. For that purpose, the proposed methodology is integrated in a Decision Support System that is capable to generate several different scenarios for each negotiation context. With this complement, the tool can also identify the most probable scenario for the identified negotiation context. A realistic case study is conducted, based on real contracts data, which confirms the learning capabilities of the proposed methodology. It is possible to identify the most probable scenario for each context over the learned period. Nonetheless, the identified scenario might not always be the real negotiation scenario, given the variable nature of such negotiations. However, this work greatly reduces the frequency of such unexpected scenarios, contributing to a greater success of the supported player over time.This work has received funding from National Funds through FCT (Fundaçao da Ciencia e Tecnologia) under the project SPET – 29165, call SAICT 2017.info:eu-repo/semantics/publishedVersio

Water Resources, Agriculture and Pasture: Implications of Growing Demand and Increasing Scarcity

Key points 1. Water availability for irrigation is threatened in many regions by rapidly increasing demand for nonagricultural water uses in industry, households, and the environment. The scarcity of irrigation water will not only impact crop production, but also meat production, as much of the pasture used to feed livestock is irrigated. 2. Grassland is caught between two countervailing forces: a requirement for increasing meat demand that boosts the need for additional pasture to support livestock production, and rapidly increasing water scarcity that makes pasture irrigation uneconomical. 3. The most effective means of dealing with water scarcity is likely to be conserving water in existing water uses. Improvements in the irrigation sector to increase water use efficiency must be made at the technical, managerial, and institutional levels. 4. Innovative water pricing policies that increase the prices for domestic and industrial water while preserving incomes for farmers and the rural poor will encourage water-saving innovation

Water Resources, Agriculture and Pasture: Implications of Growing Demand and Increasing Scarcity

Water availability for irrigation is threatened in many regions by rapidly increasing demand for nonagricultural water uses in industry, households, and the environment. The scarcity of irrigation water will not only impact crop production, but also meat production, as much of the pasture used to feed livestock is irrigated. Grassland is caught between two countervailing forces: a requirement for increasing meat demand that boosts the need for additional pasture to support livestock production, and rapidly increasing water scarcity that makes pasture irrigation uneconomical. The most effective means of dealing with water scarcity is likely to be conserving water in existing water uses. Improvements in the irrigation sector to increase water use efficiency must be made at the technical, managerial, and institutional levels. Innovative water pricing policies that increase the prices for domestic and industrial water while preserving incomes for farmers and the rural poor will encourage water-saving innovation

Influence of bottom topography on integral constraints in zonal flows with parameterized potential vorticity fluxes

An integral constraint for eddy fluxes of potential vorticity (PV), corresponding to global momentum conservation, is applied to two-layer zonal quasi-geostrophic channel flow. This constraint must be satisfied for any type of parameterization of eddy PV fluxes. Bottom topography strongly influence the integral constraint compared to a flat bottom channel. An analytical solution for the mean flow solution has been found by using asymptotic expansion in a small parameter which is the ratio of the Rossby radius to the meridional extent of the channel. Applying the integral constraint to this solution, one can find restrictions for eddy PV transfer coefficients which relate the eddy fluxes of PV to the mean flow. These restrictions strongly deviate from restrictions for the channel with flat bottom topography

Signatures of exciton coupling in paired nanoemitters

An exciton formed by the delocalized electronic excitation of paired nanoemitters is interpreted in terms of the electromagnetic emission of the pair and their mutual coupling with a photodetector. A formulation directly tailored for fluorescence detection is identified, giving results which are strongly dependent on geometry and selection rules. Signature symmetric and antisymmetric combinations are analyzed and their distinctive features identified