Impacts of a newly formed lava delta on the marine environment: Lava-induced upwelling and abrupt chlorophyll depletion during the Tajogaite eruption (La Palma, 2021) DOI Creative Commons
Alba González‐Vega, Juan Pablo Martín-Díaz, J.T. Vázquez

и другие.

The Science of The Total Environment, Год журнала: 2024, Номер 944, С. 173915 - 173915

Опубликована: Июнь 11, 2024

The 2021 Tajogaite eruption in La Palma (Canary Islands, Spain) emitted vast volumes of lava during 85 days, which reached the ocean several occasions at western flank island. Most these flows merged to create a primary delta, covering an area 48 ha, with additional 30 ha underwater. Here we characterize effects lava-seawater interaction on surrounding marine environment. was sampled two multidisciplinary oceanographic cruises: first one comprised days before and after contact; second took place month later, when delta already formed but still receiving inputs. Physical-chemical anomalies were found whole water column different depths up 300 m all measured parameters, such as turbidity (+9 NTU), dissolved oxygen concentration (−17.17 μmol kg−1), pHT25 (−0.1), chlorophyll-a (−0.33 mg m−3). Surface temperature increased +2.3 °C (28.5 °C) surface salinity showed increases decreases −1.01 +0.70, respectively, radius 4 km around delta. In column, heated waters experimented lava-induced upwelling, bringing deeper, nutrient-rich shallower depths; however, this feature did not trigger any phytoplankton bloom. fact, integrated abrupt decrease −41 % just −69 compared prior conditions. depletion distance larger than 2.5 (not delimited).

Язык: Английский

Monitoring turbidity in a highly variable estuary using Sentinel 2-A/B for ecosystem management applications DOI Creative Commons
Masuma Chowdhury, César Vílas, S.A. van Bergeijk

и другие.

Frontiers in Marine Science, Год журнала: 2023, Номер 10

Опубликована: Июль 13, 2023

The Guadalquivir estuary (southern Spain) occasionally experiences medium to high turbidity, reaching above 700 Formazin Nephelometric Unit (FNU) during extreme events, thus negatively influencing its nursery function and the estuarine community structure. Although several turbidity algorithms are available monitor water quality, they mainly developed for mapping ranges of 0-100 FNU. Thus, their use in a highly turbid region may not give accurate results, which is crucial ecosystem management. To fill this gap, we multi-conditional algorithm that can retrieve from 0 600 FNU using Sentinel-2 red red-edge bands. Four major steps implemented: atmospheric sun glint correction Level-1C data, spectral analysis different levels, regression modelling between situ remote sensing reflectance (Rrs) development, validation best-suited model. When was < 85 FNU, Rrs increased firstly wavelength (665 nm), but it saturated beyond certain threshold (> 250 FNU). At time, started increase (704 nm). Considering behavior, our designed automatically select most sensitive vs. Rrs, avoiding saturation effects bands at levels. model showed good agreement satellite derived measurements with correlation coefficient 0.97, RMSE 15.93 bias 13.34 Turbidity maps be used routine monitoring assessment potential anthropogenic actions (e.g., dredging activities), helping decision-makers relevant stakeholders protect coastal resources human health.

Язык: Английский

Процитировано

12
Evaluation of recent land-use and land-cover change in a mountain region. DOI Creative Commons
Marco Antonio Espinoza-Guzmán, David Aragonés, Francisco Javier Sahagún-Sánchez

и другие.

Trees Forests and People, Год журнала: 2023, Номер 11, С. 100370 - 100370

Опубликована: Янв. 4, 2023

Mountain regions are vital to the provision of ecosystem services. "Cofre de Perote" volcano is eighth highest mountain in Mexico and provides various goods services people living central region Veracruz. Despite being a protected area as national park, it shows processes landscape change recent years. We mapped land-use land-cover changes (LULCC) based on remote sensing data (Sentinel-2) from 2017 2021. The best classifier was support vector machine with an overall accuracy value 0.908 ± 0.003 0.916 0.004 for 2021, respectively. estimated that 21.77% changed only four main trajectory forests agricultural, ​​1224.81 ha annual rate -2.39%. Updating knowledge dynamics LULCC will allow better conservation actions ecosystems.

Язык: Английский

Процитировано

11
Machine learning for cyanobacteria inversion via remote sensing and AlgaeTorch in the Třeboň fishponds, Czech Republic DOI
Ying Ge, Feilong Shen, Petr Sklenička

и другие.

The Science of The Total Environment, Год журнала: 2024, Номер 947, С. 174504 - 174504

Опубликована: Июль 4, 2024

Язык: Английский

Процитировано

4
A General Spectral Bandpass Adjustment Function (SBAF) for Harmonizing Landsat-Sentinel over Inland and Coastal Waters DOI Creative Commons
Thainara Munhoz Alexandre de Lima, Vitor S. Martins, Rejane S. Paulino

и другие.

Science of Remote Sensing, Год журнала: 2025, Номер unknown, С. 100225 - 100225

Опубликована: Апрель 1, 2025

Язык: Английский

Процитировано

0
Thermokarst lake changes along the Qinghai-Tibet Highway during 1991–2020 DOI
Mei Mu, Cuicui Mu,

Pengsi Lei

и другие.

Geomorphology, Год журнала: 2023, Номер 441, С. 108895 - 108895

Опубликована: Сен. 3, 2023

Язык: Английский

Процитировано

10
Estimation of water quality parameters based on time series hydrometeorological data in Miaowan Island DOI Creative Commons
Yuanning Zheng, Li Cai,

Xianqing Zhang

и другие.

Ecological Indicators, Год журнала: 2024, Номер 159, С. 111693 - 111693

Опубликована: Фев. 1, 2024

Water quality parameters (WQPs), such as dissolved oxygen (DO), chemical demand (COD) and chlorophyll (Chl), are important indicators of ecosystem system. The easy availability hydro-meteorological (HMPs) provides an tool for estimating WQPs. In this study, using three empirical machine learning (ML) algorithms, namely Multi-Layer Perceptron (MLP), Random Forest (RF), M5 Model Tree (M5T), based on a large amount time series in situ monitoring HMPs WQPs data over six-month period Miaowan Island, new ML model was developed to estimate DO, COD, Chl simple cost-effective manner. Through feature selection, the input models include temperature, salinity, depth, air pressure relative humidity. results accuracy evaluation showed that RF-based optimal with R2 values 0.987, 0.992, 0.965 testing set, respectively. With model, at two sites Island were estimated temporal sequence, highly consistent measurements obtained from IEEIoTS. Furthermore, we extended application DO Zhanjiang Bay throughout August 2023. This extension WQMS, comparison measured DO. They have corresponding trends but variations values, potentially attributable inherent normality model. suggest information practical approach

Язык: Английский

Процитировано

3
Fish mortality associated to volcanic eruptions in the Canary Islands DOI Creative Commons
María José Caballero, Francisco-José Pérez-Torrado, Alicia Velázquez-Wallraf

и другие.

Frontiers in Marine Science, Год журнала: 2023, Номер 9

Опубликована: Янв. 16, 2023

The Canary Islands are an active volcanic archipelago. In the last decade, activity has occurred twice on youngest and western most islands: El Hierro (submarine eruption) in 2011-12, La Palma (subaerial 2021. 70 fish specimens of different species from volcano 14 were necropsied. A notable high early mortality fishes was registered during submarine eruption Hierro. them, generalized congestion gills, liver, spleen, kidney, heart rete mirabile swim bladder observed. Some also presented exophthalmia, gastric eversion, ocular haemorrhages, over-inflation gas bubbles mainly skin cornea. characterized by emission large amounts lava flows pyroclastic deposits (mainly ash size) both, land sea. Lava flowed eventually reached sea, forming deltas coastline Palma. This event associated with increase locations near to deltas. Fishes particles opercula/oral cavities gills. addition, several intense intestinal impaction composed material including ashes hyaloclastites fragments. To our best knowledge this study describes, for first time, pathological findings dead two styles recent eruptions Islands.

Язык: Английский

Процитировано

7
Rapid provision of maps and volcanological parameters: quantification of the 2021 Etna volcano lava flows through the integration of multiple remote sensing techniques DOI Creative Commons
Cristina Proietti, Emanuela De Beni, Massimo Cantarero

и другие.

Bulletin of Volcanology, Год журнала: 2023, Номер 85(10)

Опубликована: Сен. 13, 2023

Abstract At active volcanoes recurring eruptive events, erosive processes and collapses modify the edifice morphology impact monitoring hazard mitigation. Etna volcano (Italy) between February October 2021, 57 paroxysmal events occurred from South-East Crater (SEC), which is currently its most summit crater. Strombolian activity high lava fountains (up to 4 km) fed flows towards east, south south-west, caused fallout of ballistics (greater than 1 m in diameter) within 1–2 km SEC. The impacted area does not include permanent infrastructure, but it visited by thousands tourists. Hence, we rapidly mapped each flow before deposits became covered next event, for frequency SEC paroxysms necessitated integration data three remote sensing platforms with different spatial resolutions. Satellite (Sentinel-2 MultiSpectral Instrument, PlanetScope, Skysat Landsat-8 Operational Land Imager) drone images (visible thermal) were processed integrated extract digital surface models orthomosaics. Thermal acquired a network cameras Istituto Nazionale di Geofisica e Vulcanologia orthorectified using latest available model. This multi-sensor analysis allowed compilation geodatabase reporting main geometrical parameters flow. A posteriori quantification bulk volumes changes dense rock equivalent volume erupted magma. drone-derived enabled assessment ballistics’ distribution. developed methodology accurate characterisation frequently occurring effusive near real-time risk communication.

Язык: Английский

Процитировано

7
Development of an algal bloom satellite and in situ metadata hub with case studies in Canada DOI Creative Commons

Danielle Beaulne,

G. Fotopoulos

Ecological Informatics, Год журнала: 2023, Номер 79, С. 102447 - 102447

Опубликована: Дек. 28, 2023

Satellite remote sensing of algal blooms has been in use for almost five decades and advanced with an increasing number sensors, improvements sensor performance, developments algorithms. This progress enabled the detection monitoring increasingly optically complex water bodies small lakes, at finer spatial temporal resolutions. With climatic anthropogenic stressors impacting bloom occurrence, duration, severity, it is critical to understand characterize across a wide range scales. However, resolving both fine scales, simultaneously broad extents, provides challenges limitations current sensors. study introduces Algal Bloom Metadata Hub, application that can be used investigate freely available data from contemporary satellite sensors streamline management acquisition, particularly when interested multiple Optical hosted by hub include Sentinel-3 Ocean Land Colour Instrument (OLCI), Sentinel-2 MultiSpectral (MSI), LANDSAT-8 Operational Imager (OLI) LANDSAT-9 OLI-2; SAR Sentinel-1, RADARSAT-2, RADARSAT Constellation Mission (RADARSAT-CM). The also includes opportunity situ reporting blooms, providing potential improve understanding occurrence distribution scale. Case studies Western Basin Lake Erie Ramsey Ontario, Canada, demonstrate its utility identifying suitable data. Particularly Lake, leverage scenes integration synthetic aperture radar (SAR) on cloudy days, improved resolution higher finding was corroborated performing investigation into availability all Ontario. Further work done integrate additional update add real-time, quality test submitted (citizen) scientists.

Язык: Английский

Процитировано

7
Spatiotemporal variation of water quality in the context of suspended particulate matter in Laguna Mar Chiquita Lake, Argentina using ACOLITE DOI Creative Commons

Vivek Sivakumar,

V. Kannan,

Uppara Raghu Babu

и другие.

Desalination and Water Treatment, Год журнала: 2024, Номер 320, С. 100684 - 100684

Опубликована: Авг. 3, 2024

This study investigates seasonal variations in water quality at Laguna Mar Chiquita Lake, Argentina, by employing remote sensing techniques to analyze Suspended Particulate Matter (SPM) which offers valuable insights into the lake's environmental health. Landsat 8–9 OLI/TIRS data from 2014–2023 was utilized for spectral analysis of quality, processed using ACOLITE software accurate quantitative data. Results show SPM concentrations ranging 0.823 44.172 mg/l, with significant variations. Higher post-monsoon indicate increased anthropogenic influence, particularly northern area. Pollution tourism and industrial activities is lower pre-monsoon but spikes during monsoon, suggesting unfavorable conditions. Effective management continuous monitoring are crucial maintaining lake ecosystem

Язык: Английский

Процитировано

2