Preprints
Filtering by Subject: Environmental Monitoring
Detecting methane emissions from palm oil mills with airborne and spaceborne imaging spectrometers
Published: 2024-06-21
Subjects: Climate, Environmental Monitoring, Water Resource Management
Methane (CH4) emissions from human activities are a major cause of global warming, necessitating effective mitigation strategies. In particular, the palm oil industry generates palm oil mill effluent (POME), which continuously emits methane into the atmosphere. Satellites are becoming a powerful tool to detect and quantify methane emissions, but there is no evidence of their ability to monitor [...]
Shifts in water supply and demand shape land cover change across Chile
Published: 2024-06-19
Subjects: Environmental Indicators and Impact Assessment, Environmental Monitoring, Natural Resources and Conservation, Water Resource Management
Globally, droughts are becoming longer, more frequent, and more severe, and their impacts are multidimensional. These impacts typically extend beyond the water balance, as long-term, cumulative changes in the water balance can lead to regime shifts in land cover. Here, we assess the effects of temporal changes in water supply and demand over multiple time scales on vegetation productivity and [...]
A Comprehensive Evaluation of Multimodal Large Language Models in Hydrological Applications
Published: 2024-05-25
Subjects: Artificial Intelligence and Robotics, Environmental Monitoring, Hydrology
Large Language Models (LLMs) combined with visual foundation models have demonstrated remarkable advancements, achieving a level of intelligence comparable to human capabilities. In this study, we conduct an analysis of the latest Multimodal LLMs (MLLMs), specifically Multimodal-GPT, GPT-4 Vision, Gemini and LLaVa, focusing on their application in the hydrology domain. The hydrology domain holds [...]
Land management controls on soil carbon fluxes in Asia’s largest tropical grassland
Published: 2024-05-17
Subjects: Environmental Monitoring, Natural Resources and Conservation, Other Life Sciences
Land management changes threaten the ecological functionality of grassland ecosystems worldwide, including the ability of these ecosystems to store carbon in their soils. The Banni grasslands, Asia’s largest tropical grassland, is no different in this regard. Despite being a highly biodiverse ecosystem with an extensive land use history, information on soil carbon fluxes in this ecosystem remains [...]
Remote sensing and spatial analysis reveal unprecedented cyanobacteria bloom dynamics associated with elephant mass mortality
Published: 2024-05-07
Subjects: Climate, Environmental Microbiology and Microbial Ecology Life Sciences, Environmental Monitoring, Physical and Environmental Geography, Remote Sensing, Spatial Science, Terrestrial and Aquatic Ecology
The 2020 mass mortality of 350 African elephants (Loxodonta africana) in Botswana sparked global concern, with cyanotoxins in watering holes (pans) being a suspected cause, though evidence remains inconclusive. Combining remote sensing and spatial analysis, we examined the relationship between the ecohydrology of ~3,000 pans and the locations of deceased elephants. Our analysis revealed a [...]
Global patterns of commodity-driven deforestation and associated carbon emissions
Published: 2024-04-18
Subjects: Environmental Monitoring, Natural Resource Economics, Statistical Models, Sustainability
Rapid agriculture-driven deforestation raises significant concerns about achieving climate and biodiversity targets. Linking deforestation to food production is crucial for guiding the development, implementation, and evaluation of forest conservation and climate change mitigation efforts. However, the limited scope and comprehensiveness of available datasets restrict the effectiveness of these [...]
Advancing forest aboveground biomass mapping by integrating GEDI with other Earth Observation data using a cloud computing platform: A case study of Alabama, United States
Published: 2024-04-06
Subjects: Applied Statistics, Climate, Earth Sciences, Environmental Monitoring, Environmental Sciences, Forest Management, Other Forestry and Forest Sciences
Forest aboveground biomass (AGB) is a crucial indicator for monitoring carbon and requires accurate quantification. This study aimed to advance AGB estimation using open access Earth observation (EO) data and cloud computing, focusing on Alabama, USA. The specific objectives were to: (1) develop a workflow for creating a 30 m forest AGBD map with GEDI, using GEE, (2) evaluate and compare [...]
Evaluation of the Sentinel-1 SAR image processing algorithms performance
Published: 2024-03-08
Subjects: Environmental Monitoring, Physical Sciences and Mathematics
The following paper discussed the performance of previously developed SAR algorithms applied to Sentinel-1 imagery. The outputs of algorithms were correlated to top-performing Sentinel-2 reNDVI algorithms. The study found that Levelled and Normalized Sigma nought outperformed the Gamma Nought, and, especially, Sigma Nought, and RVI algorithms.
Estimating irrigation water use from remotely sensed evapotranspiration data: Accuracy and uncertainties at field, water right, and regional scales
Published: 2024-02-29
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Hydrology, Sustainability, Water Resource Management
Irrigated agriculture is the dominant user of water globally, but most water withdrawals are not monitored or reported. As a result, it is largely unknown when, where, and how much water is used for irrigation. Here, we evaluated the ability of remotely sensed evapotranspiration (ET) data, integrated with other datasets, to calculate irrigation water withdrawals and applications in an intensively [...]
Satellite-based surveys reveal substantial methane point-source emissions in major oil & gas basins of North America during 2022-2023
Published: 2024-02-28
Subjects: Atmospheric Sciences, Environmental Monitoring, Oil, Gas, and Energy, Remote Sensing
Utilizing imaging spectroscopy technology to identify methane super-emitters plays a vital role in mitigating methane emissions in the Oil & Gas (O&G) sector. While earlier research has uncovered significant point-source methane emissions from O&G production in the US and Canada, which are key regions with large methane emissions, a comprehensive post-COVID-19 survey has been notably [...]
A Mathematical Theory of Historical Greenhouse Gas Emissions with Rigorous Insights
Published: 2024-02-25
Subjects: Analysis, Environmental Monitoring, Longitudinal Data Analysis and Time Series, Numerical Analysis and Computation
In this paper, we analyze historical greenhouse gas (GHG) emissions worldwide, leveraging a dataset provided by (Gütschow and Pflüger, 2023). Employing mathematical modeling, a formal theory is developed, describing the growth trajectories of GHG emissions over time. The theory introduces several key concepts including continuous emission process (CEP), discrete emission process (DEP), [...]
Multi-satellite data depicts record-breaking methane leak from a well blowout
Published: 2024-02-13
Subjects: Climate, Environmental Monitoring, Oil, Gas, and Energy
Accidental blowouts in oil and gas wells can result in large and prolonged methane emissions, which are often unreported when happening in remote places. The rapid advancement of space-based methods for detecting and quantifying methane plumes provides an essential tool for uncovering these super-emission events. We use a range of methane-sensitive satellites to document a methane leak from a [...]
Deployment-invariant probability of detection characterization for aerial LiDAR methane detection
Published: 2024-01-24
Subjects: Environmental Monitoring, Environmental Sciences
Accurate detection sensitivity characterization of remote methane monitoring technologies is critical for designing, implementing, and auditing effective emissions monitoring and mitigation programs. Several research groups have developed test methods based on single/double-blind controlled release protocols and regression-based data analysis techniques to create probability of detection (PoD) [...]
Model Ensemble with Dropout for Uncertainty Estimation in Binary Sea Ice or Water Segmentation using Sentinel-1 SAR
Published: 2024-01-20
Subjects: Applied Statistics, Environmental Monitoring, Signal Processing
Despite the growing use of deep learning in sea ice mapping with SAR imagery, the study of model uncertainty and segmentation results remains limited. Deep learning models often produce overconfident predictions, a concern in sea ice mapping where misclassification can impact marine navigation safety. We incorporate and compare dropout and model ensemble within a convolutional neural network [...]
Apportioning sources of chemicals of emerging concern along an urban river with inverse modelling
Published: 2024-01-18
Subjects: Environmental Monitoring, Environmental Sciences
Concentrations of chemicals in river water provide crucial information for assessing environmental exposure to fertilisers and insecticides, heavy metals, illicit drugs, pathogens, pharmaceuticals, plastics and perfluorinated substances among others. However, using concentrations measured along waterways to identify sources of contaminants and predict their fate is complicated by downstream [...]