• Energy Research

<p><strong>Abstract: </strong>Land use and climate change are recognized as two major drivers affecting surface streamflow. On the Chinese Loess Plateau, implementation of several land restoration projects has changed land cover in recent decades. The main objectives of this study were to understand how streamflow evolved on the Loess Plateau and how land use and climate change have contributed to this change. In this study, we selected 22 hydrological modelling studies covering 25 different watersheds in the Loess Plateau and we performed a meta-analysis by using the hydrological and metrological data collected from these studies. The results indicate a streamflow decrease in 41 of a total of 52 case studies whereas precipitation change was found to be non-significant in the majority of the cases. Streamflow reduction was estimated to be -0.46mm/year by meta-analysis across all case studies. Land use change was estimated to have 63.52% impact on the streamflow reduction whereas climate change accounted for 36.48% of the impact. Using meta-regression, an increasing soil and water conservation area was found to be positively correlated to streamflow reduction. We conclude that in the Chinese Loess Plateau, streamflow shows a decreasing trend and land restoration is the major cause of this reduction. To the knowledge of the authors, this is the first study that estimates streamflow dynamics across many watersheds on the entire Loess Plateau.</p>

AbstractDespite the potential of diversification strategies to achieve sustainability, diversified systems such as agroforestry are still not widely implemented by farmers, which indicates the need to further understand and adequately assess the impacts of diversification to inform the design of complex systems. In this paper, we conduct a systematic literature review focused on agroforestry coffee systems, to assess (i) how current methods and indicators are used to quantify the impact of diversification on multiple dimensions of system sustainability, and (ii) to assess the impact of diversification through coffee agroforestry on multiple dimensions of sustainability. Our analysis was based on 215 selected papers and all the indicators identified could be classified in one of the sustainability dimensions proposed in our framework: ecosystem services (57.2%), biodiversity (35.6%), input use (4%), socio-economic sustainability (2.7%) and resilience capacity (0.5%). Despite the broad scope of the indicators, individual studies were found to often lack interdisciplinarity and a systemic view on agroecosystems. Besides, not only were there few studies that included the impacts of diversification on input use, socio-economic sustainability and resilience capacity, but specific biodiversity attributes (e.g. functional diversity, landscape diversity) and ecosystem services (e.g. soil biological quality, water regulation, pollination) were generally underreported. The impact of diversification was more positive than negative in all dimensions of sustainability, with the exception of crop productivity. Yet, diversified systems are associated with reduced costs and high yields can still be achieved in diversified systems with appropriate agricultural management (e.g. adequate number and type of shade trees). Key to reaping the benefits of diversified systems is that the diversity of elements is carefully integrated considering the impact on multiple dimensions of system sustainability. A better understanding of synergies and trade-offs remains crucial for the customized design of diverse and sustainable systems for a variety of geo-climatic conditions.

It is likely that climate change will increase irrigation water demand and, consequently, reduces water security in the Mediterranean Basin if current irrigation supply and demand conditions are maintained. Climate change adaptation can be achieved by (1) decreasing irrigation water demand through more efficient irrigation techniques, (2) increasing irrigation water supply by adopting new technological advances, (3) converting to rainfed agriculture, and (4) implementation of Nature-based Solutions for water retention. The aim of this study was to assess the effectiveness of different combinations of these adaptation options on water security through analysis of contrasting scenarios of socio-economic development. We defined plausible scenarios of climate change, land use change and adaptation measures for an intensively irrigated catchment in south-eastern Spain under three Shared Socioeconomic Pathways (SSP), representing different storylines of socio-economic development. We considered three SSP scenarios, including the Sustainability pathway (SSP1), the Middle of the Road pathway (SSP2) and the Fossil-fueled Development pathway (SSP5). Future land use distributions were obtained with the iClue land use change model by accounting for differences in irrigation water demand and supply, resulting in a decrease (SSP1), a constant (SSP2) and an increase (SSP5) in irrigated agriculture. The impact of each scenario on a series of water security indicators was quantified using the SPHY-MMF hydrology-soil erosion model. The SSP2 scenario, which considers very limited climate change adaptation, projects the most severe impacts on water security, including an increase in plant water stress, flood discharge, hillslope erosion and sediment yield. Under SSP1, which accounts for most climate change adaptation strategies, irrigation water demand is significantly reduced due to a shift from irrigated to rainfed agriculture and the implementation of reduced deficit irrigation, while Nature-based Solutions reduce the impact on other water security indicators. Under SSP5, a conversion from rainfed to irrigated agriculture causes a significant increase in irrigation water demand, which is met by increasing irrigation water supply from desalination. SSP5 shows intermediate impacts on other water security indicators, which is explained by a strong decrease in annual precipitation. This study helps exploring how different future socio-economic pathways affect water security and thereby supports evidence-based policy development.

This chapter explores the changing fire regime with reasons and consequences for forest ecosystems as well as the wildfire effects on forest soils. Furthermore, the usage and effects of post-fire salvage logging have been analyzed. The three main reasons for fire regime changes with their effects are: (1) climate change, which reduces moisture in fuels and increases the chance of wildfire ignition; (2) rural depopulation and agricultural abandonment, which lead to fuel accumulation; and (3) current policies of wildfire management focusing on fire suppression rather than on its prevention. Due to the changing fire regime, wildfires are expected to further increase in size, severity, and frequency in the future. An adequate knowledge on wildfire prevention measures (e.g., prescribed fire, salvage logging, and afforestation with less flammable species) may help land managers to identify the most effective actions for specific forest ecosystems against the prevention of irreversible land degradation.

Description: This meta-data on development and management of community managed small-scale irrigation schemes in Ethiopia is presented in a spreadsheet as a table after reviewing 83 published articles. The dataset contains research focus, data collection and analysis method, spatial scale, irrigation typology, irrigation water sources, source of energy for water conveyance from the source, main research results, scheme management systems, identified problems and provided solutions from each research article when available. The spatial scale was categorized as national, regional, district, basin, watershed or scheme, based on the spatial coverage of the research done. The irrigation typology was categorized as large-scale, medium-scale and small-scale based on the Ethiopian classification. Surface water sources such as river, lake, reservoir and flash flood and ground water sources of wells and springs or a combination of more than one source were mentioned as the water sources for irrigation schemes. The sources of energy for water abstraction were categorized as gravity, pump or a combination of both. Year of irrigation scheme commencement, available irrigation scheme infrastructure, number of beneficiaries (households), and stakeholders in scheme management were also extracted when available in the literature. Spatial coverage: Data was collected from community managed small-scale irrigation schemes located in different parts of Ethiopia. Location of some irrigation schemes (in UTM) is indicated in the dataset spreadsheet.

Pour mieux comprendre l'application mondiale des modèles de prédiction de l'érosion des sols, nous avons examiné de manière approfondie la littérature de recherche pertinente évaluée par des pairs sur la modélisation de l'érosion des sols publiée entre 1994 et 2017. Nous avons cherché à identifier (i) les processus et les modèles les plus fréquemment abordés dans la littérature, (ii) les régions dans lesquelles les modèles sont principalement appliqués, (iii) les régions qui restent non traitées et pourquoi, et (iv) la fréquence des études menées pour valider/évaluer les résultats des modèles par rapport aux données mesurées. Pour mener à bien cette tâche, nous avons combiné les connaissances collectives de 67 scientifiques spécialistes de l'érosion des sols de 25 pays. La base de données résultante, intitulée « Global Applications of Soil Erosion Modelling Tracker (GASEMT) », comprend 3030 enregistrements de modélisation individuels provenant de 126 pays, englobant tous les continents (à l'exception de l'Antarctique). Sur les 8471 articles identifiés comme potentiellement pertinents, nous avons examiné 1697 articles appropriés et systématiquement évalué et transféré 42 attributs pertinents dans la base de données. Cette base de données GASEMT fournit des informations complètes sur l'état de l'art des modèles d'érosion des sols et des applications de modèles dans le monde entier. Cette base de données vise à soutenir la prochaine évaluation mondiale de l'érosion des sols par les Nations Unies basée sur les pays, en plus d'aider à éclairer les priorités de recherche sur l'érosion des sols en construisant une base pour de futures analyses ciblées et approfondies. GASEMT est une base de données open-source à la disposition de l'ensemble de la communauté des utilisateurs pour développer la recherche, corriger les erreurs et faire des extensions futures. Para comprender mejor la aplicación global de los modelos de predicción de la erosión del suelo, revisamos exhaustivamente la literatura de investigación relevante revisada por pares sobre modelos de erosión del suelo publicada entre 1994 y 2017. Nuestro objetivo fue identificar (i) los procesos y modelos abordados con mayor frecuencia en la literatura, (ii) las regiones dentro de las cuales se aplican principalmente los modelos, (iii) las regiones que permanecen sin abordar y por qué, y (iv) con qué frecuencia se realizan estudios para validar/evaluar los resultados del modelo en relación con los datos medidos. Para realizar esta tarea, combinamos el conocimiento colectivo de 67 científicos de erosión de suelos de 25 países. La base de datos resultante, denominada 'Global Applications of Soil Erosion Modelling Tracker (GASEMT)', incluye 3030 registros de modelado individuales de 126 países, que abarcan todos los continentes (excepto la Antártida). De los 8471 artículos identificados como potencialmente relevantes, revisamos 1697 artículos apropiados y evaluamos y transferimos sistemáticamente 42 atributos relevantes a la base de datos. Esta base de datos GASEMT proporciona información integral sobre el estado del arte de los modelos de erosión del suelo y las aplicaciones de modelos en todo el mundo. Esta base de datos tiene la intención de apoyar la próxima evaluación mundial de la erosión del suelo de las Naciones Unidas basada en los países, además de ayudar a informar las prioridades de investigación de la erosión del suelo mediante la creación de una base para futuros análisis específicos y en profundidad. GASEMT es una base de datos de código abierto disponible para toda la comunidad de usuarios para desarrollar investigaciones, rectificar errores y realizar futuras expansiones. To gain a better understanding of the global application of soil erosion prediction models, we comprehensively reviewed relevant peer-reviewed research literature on soil-erosion modelling published between 1994 and 2017. We aimed to identify (i) the processes and models most frequently addressed in the literature, (ii) the regions within which models are primarily applied, (iii) the regions which remain unaddressed and why, and (iv) how frequently studies are conducted to validate/evaluate model outcomes relative to measured data. To perform this task, we combined the collective knowledge of 67 soil-erosion scientists from 25 countries. The resulting database, named 'Global Applications of Soil Erosion Modelling Tracker (GASEMT)', includes 3030 individual modelling records from 126 countries, encompassing all continents (except Antarctica). Out of the 8471 articles identified as potentially relevant, we reviewed 1697 appropriate articles and systematically evaluated and transferred 42 relevant attributes into the database. This GASEMT database provides comprehensive insights into the state-of-the-art of soil- erosion models and model applications worldwide. This database intends to support the upcoming country-based United Nations global soil-erosion assessment in addition to helping to inform soil erosion research priorities by building a foundation for future targeted, in-depth analyses. GASEMT is an open-source database available to the entire user-community to develop research, rectify errors, and make future expansions. للحصول على فهم أفضل للتطبيق العالمي لنماذج التنبؤ بتآكل التربة، قمنا بمراجعة شاملة للأدبيات البحثية ذات الصلة التي استعرضها الأقران حول نمذجة تآكل التربة المنشورة بين عامي 1994 و 2017. كنا نهدف إلى تحديد (1) العمليات والنماذج التي يتم تناولها بشكل متكرر في الأدبيات، (2) المناطق التي يتم فيها تطبيق النماذج في المقام الأول، (3) المناطق التي لا تزال دون معالجة ولماذا، و (4) عدد المرات التي يتم فيها إجراء دراسات للتحقق من صحة/تقييم نتائج النموذج بالنسبة للبيانات المقاسة. لأداء هذه المهمة، جمعنا المعرفة الجماعية لـ 67 عالمًا في مجال تآكل التربة من 25 دولة. تتضمن قاعدة البيانات الناتجة، المسماة "التطبيقات العالمية لتتبع نمذجة تآكل التربة (GASEMT )"، 3030 سجل نمذجة فردي من 126 دولة، تشمل جميع القارات (باستثناء القارة القطبية الجنوبية). من بين 8471 مقالة تم تحديدها على أنها ذات صلة محتملة، قمنا بمراجعة 1697 مقالة مناسبة وقمنا بتقييم ونقل 42 سمة ذات صلة بشكل منهجي إلى قاعدة البيانات. توفر قاعدة بيانات GASEMT هذه رؤى شاملة حول أحدث نماذج تآكل التربة وتطبيقات النماذج في جميع أنحاء العالم. تهدف قاعدة البيانات هذه إلى دعم التقييم العالمي المقبل لتآكل التربة الذي تجريه الأمم المتحدة على المستوى القطري بالإضافة إلى المساعدة في توجيه أولويات أبحاث تآكل التربة من خلال بناء أساس للتحليلات المتعمقة المستهدفة في المستقبل. GASEMT هي قاعدة بيانات مفتوحة المصدر متاحة لمجتمع المستخدمين بأكمله لتطوير البحث وتصحيح الأخطاء وإجراء التوسعات المستقبلية.