M.A. Eleveld
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6 records found
1
Modeling gross primary productivity across different European ecosystem types
Evaluating the versatility of SARIMAX, XGBoost, and LSTM using ICOS FLUXNET and Sentinel-2 data
Predicting Gross Primary Productivity (GPP) is key for understanding ecosystem health and quantifying the global carbon cycle. While data-driven models have shown strong performance in capturing GPP dynamics at specific sites, their ability to generalize across ecosystems without site-specific recalibration remains largely untested. This study addresses this gap by evaluating the applicability of XGBoost and LSTM models in estimating GPP across different European ecosystems. We developed a unified (cross-site) modeling framework that integrates in-situ eddy covariance observations and Sentinel-2–derived vegetation indices using incremental learning. Models’ performance was assessed via: (i) site-specific models, developed to capture individual site characteristics, and (ii) cross-site generalization, including evaluation on an independent dataset of unseen ecosystems. SARIMAX is included as a site-specific statistical benchmark for comparison. Our findings indicate that XGBoost consistently outperformed the other models, achieving site-specific R2 values above 0.90 in forest and grassland ecosystems and an average R2 of 0.72 across unseen sites (range 0.66–0.78). LSTM exhibited better accuracy in predicting GPP peaks at site-specific level, particularly in cropland and forest ecosystems. At site-level, SARIMAX showed comparable performance to XGBoost but struggled in capturing the rapid temporal variation of GPP. These findings demonstrate the feasibility of a data-driven framework for cross-site GPP monitoring within European flux-tower networks, making a first step toward transferable GPP prediction without site-specific recalibration.
Remote sensing technologies have the potential to support monitoring of floating plastic litter in aquatic environments. An experimental campaign was carried out in a large-scale hydrodynamic test facility to explore the detectability of floating plastics in ocean waves, comparing and contrasting different microwave and optical remote sensing technologies. The extensive experiments revealed that detection of plastics was feasible with microwave measurement techniques using X and Ku-bands with VV polarization at a plastic threshold concentration of 1 item/m2 or 1–10 g/m2. The optical measurements further revealed that spectral and polarization properties in the visible and infrared spectrum had diagnostic information unique to the floating plastics. This assessment presents a crucial step towards enabling the detection of aquatic plastics using advanced remote sensing technologies. We demonstrate that remote sensing has the potential for global targeting of plastic litter hotspots, which is needed for supporting effective clean-up efforts and scientific evidence-based policy making.
DeltaDTM
A global coastal digital terrain model
This study addresses the challenges posed by climatic changes and biodiversity loss to ecosystem stability, by quantifying gross primary production (GPP) changes. An improved earth observation product is obtained by integrating in-situ and remote sensing data via data-driven models. Employing a user-centered strategy, our methodology builds on users' engagement, ensuring both the identification of user needs and practical product demonstrations. With GEOSS as central and integrated stakeholder, we strive for a broad interoperability and accessibility of generated outcomes. The project outcomes include a curated dataset with FAIR metadata, openly available code, and reports for reproducibility, contributing to the broader Earth Intelligence supply chain.