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Understanding the impacts of climate change on water resources is of utmost importance to successful water management and further adaptations strategies. The objective of this paper is to assess the impacts of climate change on river discharge dynamics in Oueme River basin in Benin. To this end, this paper used the distribution based scaling approach to improve usability of regional climate model projections for hydrological climate change impacts studies. Hydrological simulations in Bétérou and Bonou sub-catchments of the Oueme River were carried out with a lumped conceptual hydrological model. The main contribution of this paper is to use the hydrological model based on the least action principle (HyMoLAP), which is designed to minimize uncertainties related to the rainfall-runoff process and scaling law, for this assessment. The bias correction approach allows reducing the differences between the observed rainfall and the regional climate model (HIRHAM5 and RCA4) rainfall data. Corrected and raw HIRHAM5 and RCA4 rainfall data were compared with the observed rainfall using Mean Absolute Error (MAE) and Root Mean Square error (RMSE). The results of the bias correction show a decrease in the RMSE and MAE of the raw HIRHAM5 and RCA4 rainfall data of approximately 91% to 98% in both catchments. The results of the simulation indicate that the HyMoLAP is suitable for modelling river discharge in the Oueme River basin. For the future projection based on RCP4.5 scenarios, the projected mean annual river discharge by using HIRHAM5 and RCA4 in Bétérou and Bonou decrease with the magnitude ranging respectively from −25% to −39% and −20% to −37% in the three time horizons 2020s (2011–2040), 2050s (2041–2070) and 2080s (2071–2100), representing the early, middle and late of 21st century. As regards the future projection based on RCP8.5 scenarios, the projected mean annual river discharge by using HIRHAM5 and RCA4 in Bétérou and Bonou decrease with the magnitude ranging respectively from −15% to −34% and −18% to −36% in the three time horizons. The model uncertainties projections indicated that the entire discharge distribution shifted toward more extreme events (such as drought) compared to the baseline period.

Under the urgency of rational water resource allocation and effective urban flooding control, a multi-objective interval birandom chance-constrained programming (MIBCCP) model is developed for supporting regional water resource management under multiple uncertainties and climate change in this study. Two objectives were included in this model, which are the minimization of total system costs and the maximization of total pollutant treatment amounts. The major advantage of the proposed MIBCCP model is that it realized the effective combined utilization of conventional and nonconventional water sources under complexities and uncertainties through incorporating compromise programming, birandom chance-constrained programming, and interval linear programming within a general framework. This way effectively overcomes water shortage issue and reduces urban flood frequency under climate change. A water supply management system of the educational park in Tianjin was used as a study case for demonstration. A variety of adaptive water allocation alternatives and construction schemes for LID (low-impact development) projects under RCP4.5 and RCP8.5 (representative concentration pathway 4.5 and 8.5) scenarios were obtained to deal with possible changes arising from increasing rainfall and runoff in the future. It is concluded that the proposed MIBCCP model provided the effective linkage between the utilization of nonconventional water resources and urban flood prevention and offered insights into the trade-off between economic benefits and environmental protection.

AbstractBiofuels are both a promising solution to global warming mitigation and a potential contributor to the problem. Several life cycle assessments of bioethanol have been conducted to address these questions. We performed a synthesis of the available data on Brazilian ethanol production focusing on greenhouse gas (GHG) emissions and carbon (C) sinks in the agricultural and industrial phases. Emissions of carbon dioxide (CO2) from fossil fuels, methane (CH4) and nitrous oxide (N2O) from sources commonly included in C footprints, such as fossil fuel usage, biomass burning, nitrogen fertilizer application, liming and litter decomposition were accounted for. In addition, black carbon (BC) emissions from burning biomass and soil C sequestration were included in the balance. Most of the annual emissions per hectare are in the agricultural phase, both in the burned system (2209 out of a total of 2398 kg Ceq), and in the unburned system (559 out of 748 kg Ceq). Although nitrogen fertilizer emissions are large, 111 kg Ceq ha−1 yr−1, the largest single source of emissions is biomass burning in the manual harvest system, with a large amount of both GHG (196 kg Ceq ha−1 yr−1). and BC (1536 kg Ceq ha−1 yr−1). Besides avoiding emissions from biomass burning, harvesting sugarcane mechanically without burning tends to increase soil C stocks, providing a C sink of 1500 kg C ha−1 yr−1 in the 30 cm layer. The data show a C output: input ratio of 1.4 for ethanol produced under the conventionally burned and manual harvest compared with 6.5 for the mechanized harvest without burning, signifying the importance of conservation agricultural systems in bioethanol feedstock production.

Les données sur la récolte de riz et la perte post-récolte en Afrique subsaharienne (Ass) sont rares, ce qui rend difficile pour les parties prenantes d'apprécier la perte et de définir des domaines prioritaires pour la réduction des pertes tout au long de la chaîne de valeur. Pour résoudre ce problème, un protocole a été développé et validé pour la quantification de la perte post-récolte (PHL) en Ass. Les pertes quantitatives à chaque segment ont été déterminées par des mesures sur le terrain. L'effet interactif de l'origine du riz (national contre importé) et du type de transformation (blanc contre étuvé) sur le prix du riz dans 33 marchés en Afrique a été utilisé pour estimer la perte qualitative pour le riz blanc et étuvé. La PHL totale du riz en Afrique subsaharienne en 2018 est estimée à environ 10,24 milliards de dollars américains, ce qui représente 47,63 % de la production totale attendue. La perte la plus élevée enregistrée était une perte quantitative avant et pendant la récolte, suivie d'une perte qualitative tout au long de la chaîne de valeur, d'une perte quantitative pendant le broyage, l'étuvage et le battage dans cet ordre, la plus faible étant une perte quantitative pendant le séchage. Des domaines prioritaires à cibler pour la réduction de la PHL en Afrique subsaharienne et certains outils et technologies d'atténuation des pertes pilotés ou adaptés à l'Afrique subsaharienne sont proposés. Los datos sobre la cosecha de arroz y la pérdida poscosecha en el África subsahariana (SSA) son escasos, lo que dificulta que las partes interesadas aprecien la pérdida y establezcan áreas prioritarias para la reducción de pérdidas a lo largo de la cadena de valor. Para abordar este problema, se desarrolló y validó un protocolo para la cuantificación de pérdidas poscosecha (PHL) en SSA. Las pérdidas cuantitativas en cada segmento se determinaron mediante mediciones de campo. Se utilizó el efecto interactivo del origen del arroz (nacional versus importado) y el tipo de procesamiento (blanco versus parboiled milled) en el precio del arroz en 33 mercados de África para estimar la pérdida cualitativa tanto para el arroz blanco como para el parboiled milled. El PHL total para el arroz en SSA en 2018 se estima en alrededor de US$ 10.24 mil millones, lo que representa el 47.63% de la producción total esperada. La pérdida más alta registrada fue la pérdida cuantitativa antes y durante la cosecha, seguida de la pérdida cualitativa a lo largo de toda la cadena de valor, la pérdida cuantitativa durante la molienda, la parbolización y la trilla, en ese orden, siendo la más baja la pérdida cuantitativa durante el secado. Se proponen áreas prioritarias para la reducción de PHL en SSA y algunas herramientas y tecnologías de mitigación de pérdidas experimentadas o adecuadas para SSA. Data on rice harvest and postharvest loss in Sub-Sahara Africa (SSA) is scanty making it difficult for stakeholders to appreciate the loss and set priority areas for loss reduction along the value chain. To address this problem, a protocol was developed and validated for postharvest loss (PHL) quantification in SSA. Quantitative losses at each segment were determined by field measurements. Interactive effect of origin of rice (domestic versus imported) and type of processing (white versus parboiled milled) on rice price in 33 markets in Africa was used to estimate qualitative loss for both white and parboiled milled rice. Total PHL for rice in SSA in 2018 is estimated at about US$ 10.24 billion, representing 47.63% of the expected total production. The highest loss recorded was quantitative loss before and during harvesting, followed by qualitative loss along the entire value chain, quantitative loss during milling, parboiling, threshing in that order, with the lowest being quantitative loss during drying. Priority areas to be targeted for PHL reduction in SSA and some loss mitigation tools and technologies piloted or suitable for SSA are proposed. البيانات المتعلقة بحصاد الأرز وفقدان ما بعد الحصاد في أفريقيا جنوب الصحراء ضئيلة مما يجعل من الصعب على أصحاب المصلحة تقدير الخسارة وتحديد المجالات ذات الأولوية للحد من الخسارة على طول سلسلة القيمة. ولمعالجة هذه المشكلة، تم وضع بروتوكول والتحقق من صحته من أجل التحديد الكمي لخسائر ما بعد الحصاد في جنوب الصحراء الكبرى بأفريقيا. تم تحديد الخسائر الكمية في كل قطاع من خلال القياسات الميدانية. تم استخدام التأثير التفاعلي لمنشأ الأرز (المحلي مقابل المستورد) ونوع المعالجة (الأبيض مقابل المطحون المسلوق) على سعر الأرز في 33 سوقًا في إفريقيا لتقدير الخسارة النوعية لكل من الأرز الأبيض والمطحون المسلوق. يقدر إجمالي PHL للأرز في جنوب الصحراء الكبرى في عام 2018 بحوالي 10.24 مليار دولار أمريكي، وهو ما يمثل 47.63 ٪ من إجمالي الإنتاج المتوقع. كانت أعلى خسارة مسجلة هي الخسارة الكمية قبل وأثناء الحصاد، تليها الخسارة النوعية على طول سلسلة القيمة بأكملها، والخسارة الكمية أثناء الطحن، والغليان، والدرس بهذا الترتيب، مع أقل خسارة كمية أثناء التجفيف. يتم اقتراح المجالات ذات الأولوية التي سيتم استهدافها لخفض مستوى المعيشة في الفلبين في جنوب الصحراء الكبرى وبعض أدوات وتقنيات التخفيف من الخسائر التي تم تجريبها أو المناسبة لجنوب الصحراء الكبرى.

Rainfed agriculture is becoming increasingly vulnerable to climate change. This situation is expected to worsen under most future climate projections, which might increase the risks linked to food security and economies which depend on it. Providing insights about the potential responses of rainfed crops to climate change will helps on designing future adaptation strategies. In this study, large amount of data and the agro-hydrological model SWAT have been used to investigate future climate change impacts on rainfed wheat and sunflower crops in a semiarid watershed in Morocco (R’dom watershed). Downscaled CORDEX climate projections were used in generating future plants growth simulation for R’dom watershed in the 2031 to 2050 horizon under two Representative Concentration Pathways (RCPs): 4.5 and 8.5. The main results of climate change scenarios highlighted that R’dom watershed will undergo significant decrease in water resources availability with more impact under the scenario RCP 8.5. Water productivities of both studied crops could be lower by up to -21% in comparison with baseline situation. Different sustainable management strategies have been simulated using SWAT model under climate change context. The adopted approach succeeded in building up sustainable management strategies toward secured food security in the future.

AbstractAt high latitudes, longwave radiation can provide similar, or higher, amounts of energy to snow than shortwave radiation due to the low solar elevation (cosine effect and increased scattering due to long atmospheric path lengths). This effect is magnified in mountains due to shading and longwave emissions from the complex topography. This study examines longwave irradiance at the snow surface in the Wolf Creek Research Basin, Yukon Territory, Canada (60° 36′N, 134° 57′W) during the springs of 2002 and 2004. Incoming longwave radiation was estimated from standard meteorological measurements by segregating radiation sources into clear sky, clouds and surrounding terrain. A sensitivity study was conducted to detect the atmospheric and topographic conditions under which emission from adjacent terrain significantly increases the longwave irradiance. The total incoming longwave radiation is more sensitive to sky view factor than to the temperature of the emitting terrain surfaces. Brutsaert's equation correctly simulates the clear‐sky irradiance for hourly time steps using temperature and humidity. Longwave emissions from clouds, which raised longwave radiation above that from clear skies by 16% on average, were best estimated using daily atmospheric shortwave transmissivity and hourly relative humidity. An independent test of the estimation procedure for a prairie site near Saskatoon, Saskatchewan, Canada, indicated that the calculations are robust in late winter and spring conditions. Copyright © 2006 John Wiley & Sons, Ltd.

Habitat characteristics play a critical role in structuring reef fish communities subjected to fishing pressure. The line intercept transect (LIT) method provides an accurate quantitative description of the habitat, but in a very narrow corridor less than 1 m wide. Such a scale is poorly adapted to the wide-ranging species that account for a significant part of these assemblages. We developed an easy-to-use medium scale approach (MSA), based on a semi-quantitative description of 20 quadrats of 25 m 2 (500 m 2 in total). We then simulated virtual reef landscapes of different complexities in a computer, on which we computed MSA using different methods of calculation. These simulations allowed us to select the best method of calculation, obtaining quantitative estimates with acceptable accuracy (comparison with the original simulated landscapes: R 2 ranging from 0.986 to 0.997); they also showed that MSA is a more efficient estimator than LIT, generating percentage coverage estimates that are less variable. A mensurative experiment based on thirty 50-m transects, conducted by three teams of two divers, was used to empirically compare the two estimators and assess their ability to predict fish–habitat relationships. Three-factor multivariate ANOVAs (Teams, Reef, Methods) revealed again that LIT produced habitat composition estimates that were more variable than MSA. Canonical analyses conducted on fish biomass data successively aggregated by mobility patterns, trophic groups, and size classes, showed the higher predictive power of MSA habitat data over LIT. The MSA enriches the toolbox of methods available for reef habitat description at intermediate scale (b1000 m 2 ), between the scale where LIT is appropriate (b100 m 2 ) and the landscape approach (N1000 m 2 ).