Harmonizing and combining existing land cover/land use datasets for cropland area monitoring at the African continental scale

Mapping cropland areas is of great interest in diverse fields, from crop monitoring to climate change and food security. Recognizing the value of a reliable and harmonized crop mask that entirely covers the African continent, the objectives of this study were to (i) consolidate the best existing land cover/land use datasets, (ii) adapt the Land Cover Classification System (LCCS) for harmonization, (iii) assess the final product, and (iv) compare the final product with two existing datasets. Ten datasets were compared and combined through an expert-based approach to create the derived map of cropland areas at 250m covering the whole of Africa. The resulting cropland mask was compared with two recent cropland extent maps at 1km: one derived from MODIS and one derived from five existing products. The accuracy of the three products was assessed against a validation sample of 3591 pixels of 1km regularly distributed over Africa and interpreted using high resolution images, which were collected using the Geo-Wiki tool. The comparison of the resulting crop mask with existing products shows that it has a greater agreement with the expert validation dataset, in particular for places where the cropland represents more than 30% of the area of the validation pixel.JRC.H.4-Monitoring Agricultural Resource

Reativação Tectônica Quaternária no Domínio Sul da Província Borborema, NE do Brasil: Integração de Dados Morfométricos, Geológicos e Geofísicos da Bacia do Rio Una

Integração de dados em diferentes escalas foi realizada com o objetivo de identificar possíveis efeitos de reativações tectônicas cenozoicas (pós-rifte), relacionadas ao embasamento adjacente à Bacia Pernambuco, sobre o qual está localizada a bacia hidrográfica do Rio Una. O estudo foi baseado na integração de parâmetros morfométricos do canal do Rio Una, modelados a partir de imagens de radar, dados de geologia de superfície e dados de sísmica de reflexão multicanal 2D adquiridos no canal do rio, próximo às cidades de Barreiros e Palmares. A análise morfométrica se baseou no cálculo da relação declividade vs. extensão (RDE) ao longo do perfil longitudinal do Rio Una. Dados geológicos foram coletados em afloramentos no embasamento próximo aos municípios de Barreiros e Palmares. Também foram investigados os depósitos da Formação Barreiras na região costeira, próximo ao município de São José da Coroa Grande. A análise do perfil longitudinal mostrou que o Rio Una está implantado sobre três superfícies criadas por eventos sucessivos de soerguimento e erosão, as quais controlaram a compartimentação de sua bacia hidrográfica. O estudo do índice RDE mostrou a ocorrência de anomalias de primeira ordem, no médio curso, e de segunda ordem, no médio e baixo curso do rio. As anomalias de primeira e segunda ordem estão localizadas sobre as principais zonas de cisalhamento pré-cambrianas que cortam o embasamento com orientação NE-SW. As anomalias também estão relacionadas a falhas e fraturas mais jovens com direção NW-SE. A interpretação dos dados sísmicos mostrou um arranjo de falhas e fraturas de alto ângulo no embasamento que afetaram depósitos sedimentares de idade quaternária e holocênica. Também foram observadas falhas em depósitos da Formação Barreiras (Mioceno) depositados sobre o embasamento próximo a borda da Bacia Pernambuco. A geometria dos planos de falha é indicativa de estruturas do tipo flor, relacionadas a um regime de reativação transcorrente que está atuando sobre a margem continental, com compressão máxima E-W e extensão N-S. Este regime afetou a morfologia do canal do Rio Una, bem como os depósitos sedimentares associados à sua bacia de drenagem

Economics of hunger : several methods, levels and scales

Chronic or acute malnutrition are still a daily reality for more than 852 millions of people in the world. The reasons for this are numerous. Natural disasters, wars, chronic poverty, information asymmetries and market imperfections are some of them. This thesis aims to cover a large range of issues, from the household to the international level, which underlie the food insecurity problem in Niger. Its purpose is to help decision makers in their fight against hunger. It aims to do so by, giving a better understanding of the mechanisms that jeopardize access to food and, by developing decision support tools. First, in terms of food production, the author analyses how the actual spatial dispersion of the fields of a household influences its fertilization strategies. The results show that farmers are able to adopt complex spatial fertilization strategies in order to reduce the agricultural risk of their farm. Moreover, they demonstrate that the low rate of adoption of modern fertilization techniques can be explained by a wish of diversification. However, food security can only be achieved if grains can move from surplus areas to deficit areas. The author therefore proposes a technique that measures the integration among cereal markets and determines what can be done to improve their functioning. The integration seems to vary significantly among the Nigerien markets. In addition, improving communication infrastructures appeared to be a promising policy for increasing market integration. Finally, as humanitarian interventions are still needed in Niger, a new vulnerability assessment methodology, namely Econometric-Kriging-Bayesian (EKB), was elaborated so as to make an efficient use of all available data and to map vulnerable zones at the village level. In addition, the present Nigerien food aid mechanism has been shown to engender market distortions that may cause a food crisis through self-fulfilling expectations.Doctorat en sciences agronomiques et ingénierie biologique (AGRO 3)--UCL, 200

Characterization of the Operation of a BESS with a Photovoltaic System as a Regular Source for the Auxiliary Systems of a High-Voltage Substation in Brazil

Substation (SS) auxiliary systems (SAux) are facilities responsible for hosting the alternating (AC) and direct current (DC) busbar to serve the equipment and systems that perform the substation’s protection, control, and supervision. External and internal power supplies typically ensure the continuity of such a facility. The electricity support will be restricted to diesel emergency generators (DG) if the external power supply is unavailable due to a contingency. The DG present a slower response time and are susceptible to starting failures. Microgrids with Battery Energy Storage Systems (BESS) paired with photovoltaic systems (PV) are presented as an innovative and reliable solution for powering the SAux. In this article, tests were carried out on the microgrid of the Edson Mororó Moura Institute of Technology (ITEMM) in Brazil to support the use of microgrids BESS/PV in the SAux of a transmission SS of the São Francisco Hydroelectric Company (Chesf). Without an external power supply, BESS commands the action of islanded operation, maintaining both voltage and frequency requirements of the microgrid without load shedding. It was possible to observe all operations of the microgrid. The experimental results showed that the solution proposed in the paper implements a dependable self-dispatchable autonomous power supply

Neotropical freshwater fisheries : A dataset of occurrence and abundance of freshwater fishes in the Neotropics

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data