Thesis

Simulating and analyzing climate change impacts on crop yields in Morocco
Iliass Loudiyi (UMCCB)

Salle A4, Petits Amphithéâtres - Galerie des Arts
Bâtiment B7b, Quartier Agora, Allée du 6 Août, 15, B-4000 Liège 1 (Sart-Tilman)

Cereal production is a cornerstone of Morocco’s agriculture and food security, covering more than half of the country’s farmland. Yet this vital sector faces growing challenges due to climate change, with more frequent droughts, rising temperatures, and increasingly erratic rainfall already destabilizing yields and increasing reliance on imports.

This research examines how Morocco’s cereal sector can adapt to these changing conditions while maintaining long-term productivity. The study combines three complementary approaches: advanced crop growth simulations using the CARAIB dynamic vegetation model, high-resolution regional climate projections, and machine learning techniques to identify the most critical drivers of yield variability.

Findings indicate that, under a high-emission (RCP 8.5) scenario, cereal yields could decline by 10% to 35% by the 2080s. The atmospheric CO₂ fertilization effect may help sustain production until mid-century, but its benefit diminishes as drought, water stress, and temperature extremes intensify. However, adaptation strategies show strong potential. In particular, evaluating different sowing windows indicates that sowing in December consistently delivers higher and more stable yields, whereas sowing in early September or late January can reduce production by up to one-third. Growth cycles are also projected to shorten significantly by the end of the century, reducing the duration of grain development and further constraining productivity. Machine learning analysis highlights precipitation timing, water stress, and temperature extremes during the flowering and grain-filling stages as key drivers of yield variability.

In conclusion, this research bridges the gap between climate science and agricultural policy, offering robust, quantitative recommendations to guide both immediate and long-term adaptation strategies. The methods are transferable to other semi-arid regions confronting comparable threats to food security. By strengthening evidence-based decision-making, the study supports Morocco’s national development priorities while advancing the Sustainable Development Goals on climate adaptation and food security.

Assessment and future projection of climate change impacts on terrestrial ecosystem productivity and carbon balance using satellite/model approach
Arpita Verma (UMCCB)

Salle A4, Petits Amphithéâtres - Galerie des Arts
Bâtiment B7b, Quartier Agora, Allée du 6 Août, 15, B-4000 Liège 1 (Sart-Tilman)

Forests and grasslands are central to Europe’s carbon balance, biodiversity, and climate resilience. Yet both ecosystems are increasingly affected by climate change and land-use transitions, which determine how much carbon they can store, how efficiently plants use water, and how well they can withstand droughts. In Wallonia, Belgium, where forests cover more than half the territory, understanding these dynamics is essential for sustainable land and forest management.

This research developed a high-resolution simulation framework that integrates satellite-based land cover maps, species trait information, and regional climate projections within the CARAIB Dynamic Vegetation Model. The framework reconstructed ecosystem functioning from 1980 to 2020 and explored trajectories until 2070 under contrasting climate (RCP2.6 and RCP8.5), land-use, and management scenarios.

The results show that forests have generally accumulated carbon over recent decades, while grasslands, though highly productive, are more vulnerable to heat and drought stress. Conservation and afforestation scenarios enhanced carbon storage and ecosystem resilience, but these gains diminished under severe climate change. Adaptive forest management strategies, particularly thinning and regeneration, improved water-use efficiency and drought resilience for most species. Species responses diverged markedly: alder (Alnus glutinosa) maintained strong resilience, while poplar (Populus nigra) and Scots pine (Pinus sylvestris) proved highly sensitive in unmanaged, high-emission futures.

By introducing species-level resilience indicators and combining land-use and management pathways with climate projections, this thesis provides new insights into carbon dynamics, water-use efficiency, and drought adaptation. Its findings offer a robust scientific basis for land-use and forest policies that aim to sustain carbon storage, biodiversity, and resilience in temperate regions under accelerating climate change.

Towards a better understanding of the meteoroid complex using forward scatter radio observations of the BRAMS network
Joachim Balis (COMETA)

Salle A3, Petits Amphithéâtres - Galerie des Arts
Bâtiment B7b, Quartier Agora, Allée du 6 Août, 15, B-4000 Liège 1 (Sart-Tilman)

Every day, millions of meteoroids enter Earth’s atmosphere. Studying them provides valuable insights into the distribution and properties of dust and small bodies in the Solar System, the dynamics of the upper atmosphere, and the influx of extraterrestrial material to Earth. Their very high speeds also pose a significant threat to spacecraft.
This thesis explores how forward scatter continuous wave radio observations can be used to reconstruct meteoroid trajectories and speeds. The work is based on data from the Belgian RAdio Meteor Stations (BRAMS) network. BRAMS offers several advantages over traditional radars, including wider detection coverage, higher sensitivity, and lower cost.
Results demonstrate that BRAMS can effectively contribute to the systematic retrieval of meteoroid trajectories and speeds. This work paves the way for characterizing smaller and higher-altitude objects inaccessible to optical systems, enhancing our understanding of the meteoroid complex.