Publications of Joost Wellens
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See detailSimulating and analysing climate change impacts on crop yields in Morocco using the CARAIB dynamic vegetation model driven by Med- CORDEX projections
Loudiyi, Iliass ULiege; Jacquemin, Ingrid ULiege; Tychon, Bernard ULiege et al

Conference (2020, May 08)

Morocco, by its geographical position and its climate, is strongly affected by climate change and presents an ever-increasing vulnerability. In fact, the country's economy, being very dependent on ... [more ▼]

Morocco, by its geographical position and its climate, is strongly affected by climate change and presents an ever-increasing vulnerability. In fact, the country's economy, being very dependent on agriculture, would be greatly affected. It is therefore necessary to further develop knowledge about climate change and strengthen forcasting systems for predicting the impacts of climate change. The agriculture in Morocco is largely dominated by rainfed crops and therefore dependent on pluviometry. According to the Global Yield Gap Atlas, about 43% of arable land is devoted to cereals, 7% to plantation crops (olives, almonds, citrus, grapes, dates), 3% to pulses, 2% to forage, 2% to vegetables, 2% to industrial crops (sugar beets, sugar cane, cotton) and oilseeds, and 42% is fallow. In this project we are going to focus on cereals, olives, potatoes and sugar beets. Regarding the climate, Morocco is characterized by a wide variety of topographies ranging from mountains to plains, oasis and Saharan dunes. For this reason, the country experiences diverse climatic conditions with large spatial and intra- and inter-annual variability of precipitation. Morocco faces irregular rain patterns, cold spells and heat waves increasingly resulting in droughts, which significantly affects agriculture. Our research, funded by a bilateral project of Wallonie-Bruxelles International, aims to study the response of Moroccan agriculture to climate change, using the dynamic vegetation model CARAIB (CARbon Assimilation In the Biosphere) developed within the Unit for Modelling of Climate and Biogeochemical Cycles (UMCCB) of the University of Liège. This spatial model includes crops and natural vegetation and may react dynamically to land use changes. Originally constructed to study vegetation dynamics and carbon cycle, it includes coupled hydrological, biogeochemical, biogeographical and fire modules. These modules respectively describe the exchange of water between the atmosphere, the soil and the vegetation, the photosynthetic production and the evolution of carbon stocks and fluxes in this vegetation-soil system. The biogeographical module describes, for natural vegetation, the establishment, growth, competition, mortality, and regeneration of plant species, as well as the occurrence and propagation of fires. For crops, a specific module describes basic management (sowing, harvest, rotation) and phenological phases. Model simulations are performed across north-west Morocco, where the crops activities are important, by using different input data. The timeline of simulations is divided in two periods: past (from 1901 to 2018[LF1] ) and future (from 2019 to 2100). For the past period, we are using high resolution (30 arc sec) gridded climate data derived from WorldClim (climatology) and interpolated anomalies from Climate Research Unit CRU (trend and variability). For the future period, we use interpolated and bias-corrected fields from a regional climate model (ALADIN-Climate) from the Med-CORDEX initiative run at a spatial resolution of 12 km and for three different Representative Concentration Pathway scenarios (RCP2.6, RCP4.5 and RCP8.5). [less ▲]

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See detailDiagnostic d’un système d’informations de gestion de l’eau à usage agricole dans le sous-bassin versant de la Haute-Comoé, Burkina Faso.
Pale, Sié ULiege; Traoré, Farid; Wellens, Joost ULiege et al

in GEO-ECO-TROP (2019), 43(3, n.s.)

L’agriculture irriguée, moteur économique du sous-bassin versant de la Haute-Comoé, est confrontée à de nombreux défis, à cause entre autres de la mauvaise gestion des ressources en eau de surface, qui se ... [more ▼]

L’agriculture irriguée, moteur économique du sous-bassin versant de la Haute-Comoé, est confrontée à de nombreux défis, à cause entre autres de la mauvaise gestion des ressources en eau de surface, qui se raréfient. L’insuffisance de communications entre les usagers a conduit parfois à des tensions perceptibles. Au regard de ce constat et face à un système national inopérant, les parties prenantes de la « Gestion Intégrée des Ressources en Eau », à travers le Comité Local de l’Eau (CLE), ont décidé de mettre en place un système de production et de partage d’informations. Une enquête qualitative réalisée pendant les campagnes sèches 2016 et 2017, a permis d’analyser le système, de repérer ses forces et faiblesses et de faire des propositions. Il ressort de cette analyse que le programme de lâchers d’eau à partir des trois principaux réservoirs contrôlant les eaux de surface, est au centre du système d’information du CLE et sa principale force réside dans la démarche de production de l’information. Le maillon « diffusion », reste cependant faible et il devrait être amélioré par des outils de communication de masse. [less ▲]

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See detailIntegrated Water Resources Management: past, present and future
Wellens, Joost ULiege; Derouane, Johan; Pale, Sié ULiege et al

in Geo-Eco-Trop (2019)

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See detailOpen Data and AquaCrop : sorghum yield estimates in support to food security in Niger
Mohamed Sallah, Abdoul-Hamid ULiege; Wellens, Joost ULiege; Garba, Issa et al

Poster (2019, September 20)

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See detailBatch-processing of AquaCrop plug-in for rainfed maize using satellite derived Fractional Vegetation Cover data
Mohamed Sallah, Abdoul-Hamid ULiege; Tychon, Bernard ULiege; Piccard, Isabelle et al

in Agricultural Water Management (2019), 217(346-355),

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See detailUsing multi-temporal landsat images and support vector machine to assess the changes in agricultural irrigated areas in the mogtedo region, burkina faso
Traoré, Farid; Bonkoungou, Joachim; Compaoré, Jérôme et al

in Remote Sensing (2019), 11(12),

Over the last few decades, small-scale irrigation has been implemented in Burkina Faso as a strategy to mitigate the impacts of adverse climate conditions. However, the development of irrigated perimeters ... [more ▼]

Over the last few decades, small-scale irrigation has been implemented in Burkina Faso as a strategy to mitigate the impacts of adverse climate conditions. However, the development of irrigated perimeters around small and medium water reservoirs has put the water resources under significant pressure, given the uncontrolled exploitation and lack of efficacious management plan. Insights into changes in irrigated areas around these reservoirs are therefore crucial for their sustainable management while meeting the different agricultural water needs. They will help to center policy priorities in terms of major impacts on the reservoirs; and thereby elaborate relevant mitigation and/or adaptation strategies. The main objectives of this study were to (1) quantify the changes in irrigated land areas surrounding the Mogtedo water reservoir between 1987 and 2015; and (2) determine whether the irrigable potential of this reservoir could sustainably meet the agricultural water needs under a more variable and changing climate. A low-cost remote sensing method based on Landsat imagery (Thematic Mapper, Enhanced Thematic Mapper Plus, and Operational Land Imager) and using Support Vector Machine (SVM) classification was developed to detect the changes in proportion of land use/land cover (LULC) in the Mogtedo region. A forward and backward change detection analysis requiring agronomic expertise was also applied to correct the pixels temporal trajectories. In addition, an intensity analysis was performed to assess land changes at time intervals, category, and transition levels. Five main LULC classes were identified: bare and hydromorphic soils, irrigated and rainfed agricultural areas, and water bodies. Overall, the classification of LULC was satisfactory with the overall accuracy and kappa coefficients ranging from 94.22 to 95.60% and 0.92 to 0.94, respectively. Results showed that LULC transformations were faster between 2000 and 2015, compared to the 1987-2000 period. The majority of categories (LULC classes) were active in terms of intensity of change (gain or loss) during the 1987-2000 and 2000-2015 periods, except hydromorphic soils. During these periods, the transition from rainfed agricultural areas to irrigated agricultural areas were targeted and stationary. Our findings revealed a 54% increase in irrigated areas between 1987 and 2015. The reservoir water volume decreased markedly from 9,077,000 m3 to 7,100,000 m3 during the same period. Such a decrease threatens the satisfaction of agricultural water requirements, since the reservoir is the unique source of irrigation water in the region. It could potentially lead to conflicts between users if adequate strategies for the sustainable management of the Mogtedo reservoir are not implemented. The methodology used in this study also addressed the challenge of building up historical spatial information database in data-scarce environments, and could be replicated readily in regions or countries like Burkina Faso. © 2019 by the authors. [less ▲]

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See detailL'eau dans les pays en développement: un marché à quel prix? Quelles solutions?
Wellens, Joost ULiege

Conference given outside the academic context (2018)

Detailed reference viewed: 20 (2 ULiège)
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See detailAquaCrop and ICT to improve irrigation efficiencies
Wellens, Joost ULiege; Wahbi, Amar; Tychon, Bernard ULiege et al

in FAO /IAEA Soils Newsletter (2018), 40(2),

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See detailEO_Regions_Science: Basic Research in support of EO_Regions!
Orban, Anne ULiege; Barbier, Christian ULiege; Billen, Roland ULiege et al

Conference (2018, January)

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See detailPerformance du modèle AquaCrop pour la prévision des rendements du blé tendre au Maroc
Wellens, Joost ULiege

Scientific conference (2017, December 20)

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See detailCiné-débat: Merci pour la pluie
Wellens, Joost ULiege

Conference given outside the academic context (2017)

Detailed reference viewed: 30 (4 ULiège)
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See detailCrowdsourcing for agricultural applications: A review of uses and opportunities for a farmsourcing approach
Minet, Julien ULiege; Curnel, Yannick; Gobin, Anne et al

in Computers and Electronics in Agriculture (2017), 142, Part A

Abstract Crowdsourcing, understood as outsourcing tasks or data collection by a large group of non-professionals, is increasingly used in scientific research and operational applications. In this paper ... [more ▼]

Abstract Crowdsourcing, understood as outsourcing tasks or data collection by a large group of non-professionals, is increasingly used in scientific research and operational applications. In this paper, we reviewed crowdsourcing initiatives in agricultural science and farming activities and further discussed the particular characteristics of this approach in the field of agriculture. On-going crowdsourcing initiatives in agriculture were analysed and categorised according to their crowdsourcing component. We identified eight types of agricultural data and information that can be generated from crowdsourcing initiatives. Subsequently we described existing methods of quality control of the crowdsourced data. We analysed the profiles of potential contributors in crowdsourcing initiatives in agriculture, suggested ways for increasing farmers’ participation, and discussed the on-going initiatives in the light of their target beneficiaries. While crowdsourcing is reported to be an efficient way of collecting observations relevant to environmental monitoring and contributing to science in general, we pointed out that crowdsourcing applications in agriculture may be hampered by privacy issues and other barriers to participation. Close connections with the farming sector, including extension services and farm advisory companies, could leverage the potential of crowdsourcing for both agricultural research and farming applications. This paper coins the term of farmsourcing as a professional crowdsourcing strategy in farming activities and provides a source of recommendations and inspirations for future collaborative actions in agricultural crowdsourcing. [less ▲]

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See detailPotato monitoring in Belgium with "watchITgrow"
Piccard, Isabelle; Gobin, Anne; Wellens, Joost ULiege et al

in 19th International Workshop on the Analysis of Multitemporal Remote Sensing Images (2017, June 29)

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See detailAssessment of AquaCrop for winter wheat using satellite derived fCover data
Mohamed Sallah, Abdoul-Hamid ULiege; Wellens, Joost ULiege; Tychon, Bernard ULiege et al

in 9th International Workshop on the Analysis of Multitemporal Remote Sensing Images (2017, June 29)

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See detailLa gestion de l'eau dans les pays en développement ou GIRE: passé, présent et future
Wellens, Joost ULiege

Conference (2017, March 29)

Detailed reference viewed: 41 (4 ULiège)