CEFAS03567764-da98-433d-b8cf-29a07f2156a2 English dataset Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk pointOfContact 2025-08-28T11:00:35 EPSG Geodetic Parameter Registry 2022-01-07 revision WGS 84 Riverine plume extent and frequency between 2017-2023 in Sri Lanka's Exclusive Economic Zone and southern tip of India 2025-06-17 publication 2025-08-28 revision 2025-06-09 creation CEFAS22242 https://data.cefas.co.uk Riverine plume extent and the frequency of plume occurrence between 2017-2023 derived from ocean colour Sentinel-3 Ocean and Land Colour Instrument (OLCI) data in Sri Lanka's Exclusive Economic Zone (EEZ) and southern tip of India. This data was created under Ocean Country Partnership Programme (OCPP) funded Defra (funding: project number GB-GOV-7-BPFOCPP) Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk originator Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk custodian Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk distributor Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) data.manager@cefas.co.uk owner notPlanned Ecology Estuary Exposure Monitoring GEMET, version 1.0 2008-06-01 publication River flow and discharge SeaDataNet P02 parameter discovery vocabulary 2011-03-25 revision Habitats and biotopes Area management/restriction/regulation zones and reporting units GEMET - INSPIRE themes, version 1.0 2008-06-01 publication Unknown SeaVoX Vertical Co-ordinate Coverages 2010-05-18 revision Marine Environmental Data and Information Network MEDIN metadata record availability 2012-01-11 publication data.gov.uk MEDIN metadata record availability 2012-01-11 publication otherRestrictions noLimitations otherRestrictions Publicly available data licensed under the Open Government Licence v3.0 ( `https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/`_ ) – Please note the applicable attribution statement is as follows: ‘includes Crown copyright, Cefas 2025' .. _`https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/`: https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ English environment boundaries 70.00 90.00 0.00 20.00 2017-01 2023-12 Binary Delimited Geographic Information System Unknown https://data.cefas.co.uk/view/22242 Cefas Data Portal download The Cefas Data Portal contains metadata records and data sets available to download and connect to in support of our commitment to open science. Data is available in the following formats: Binary download, CSV, ESRI Shapefile. The data can also be accessed via the WFS and WMS protocols. dataset INSPIRE Data Specification on Habitats and Biotopes – Technical Guidelines 2013-12-10 publication false See the referenced specification INSPIRE Data Specification on Area Management/Restriction/Regulation Zones and Reporting Units – Technical Guidelines 2013-12-10 publication false See the referenced specification Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 publication true See the referenced specification Methodology of deriving plume extent and frequency. Sentinel-3 OLCI L1 data was atmospherically corrected using Polymer atmospheric correction to derive water leaving reflectance (Rw). Rw was used to calculate Forel-Ule Index (FUI) in Python based on the GitHub repository here: `https://github.com/CefasRepRes/FUME`_ FUI is a 21 colour scale ranging from indigo blue to cola brown, qualitatively describing bio-geo-chemical properties of the water ( `http://www.citclops.eu/water-colour/measuring-water-colour`_). Daily FUI values were resampled to a regular grid and aggregated to monthly composites using mean FUI per pixel. Statistics (mean, minimum, maximum per pixel) between 2017-2023 were calculated using the mean monthly FUI composites. Maximum mean FUI between 2017-2023, where FUI>=10, was used as a threshold to map the presence of the plume extent based on Fronkova et al, 2022 `https://doi.org/10.3390/rs14102375`_. The contour of the plume extent was simplified using 5km distance using ArcGIS Pro. Frequency of FUI>= 10 was calculated in Python and normalised between 0 and 1, where 1 means the plume occurred all of the times between 2017-2023 in the particular pixel, and 0 means no data. The plume frequency was calculated based on four seasons in Sri Lanka: 1. First inter-monsoon (March-April): SLK_plume_freq_mean_first_intermoons_2017_2023.tif 2. Southwest monsoon (May-September): SLK_plume_freq_mean_sw_monsoon_2017_2023.tif 3. Second inter-monsoon (October-November): SLK_plume_freq_mean_second_intermonsoon_2017_2023.tif 4. Northeast monsoon (December-February): SLK_plume_freq_mean_ne_monsoon_2017_2023.tif Spatial resolution of the frequency data is 300m and EPSG 4326 (geotiffs) **Input data sources for the analysis: **Copernicus Sentinel data [2017 - 2023] , EUMETSAT products 0409 and 0577 `https://data.eumetsat.int/product/EO:EUM:DAT:0409`_ and `https://data.eumetsat.int/product/EO:EUM:DAT:0577`_ .. _`https://github.com/cefasrepres/fume`: https://github.com/CefasRepRes/FUME .. _`http://www.citclops.eu/water-colour/measuring-water-colour`: http://www.citclops.eu/water-colour/measuring-water-colour .. _`https://doi.org/10.3390/rs14102375`: https://www.mdpi.com/2072-4292/14/10/2375 .. _`https://data.eumetsat.int/product/eo:eum:dat:0409`: https://data.eumetsat.int/product/EO:EUM:DAT:0409 .. _`https://data.eumetsat.int/product/eo:eum:dat:0577`: https://data.eumetsat.int/product/EO:EUM:DAT:0577 MEDIN 3.1.1