Mapping benthic habitat with remote sensing in optically complex coastal enviroments
type: CreativeWork
description: Benthic algal cover and trends in its changes are indicators of water state in coastal areas. Remote sensing could provide a tool for mapping bottom vegetation if the substrates are spectrally resolvable. We measured reflectance spectra and collected spectral library of typical bottom types of Estonian coastal waters concentrating mainly on red, green, and brown macroalgae. The spectral library together with a bio-optical model allows estimating the suitability of different remote sensing sensors for mapping Baltic Sea bottom types. The modelling results indicate that the maximum depths where hyperspectral remote sensing instruments could potentially detect the spectral differences between the three most typical green, brown and red benthic macroalgae are greater than the depths where the studied algae actually occur in Estonian coastal waters if the sensor’s SNR is better than 1000:1. To some extent it is possible to map green, red and brown algae with multispectral satellite sensors in turbid waters, which optical properties resemble those of the open Baltic Sea, but the depths where the macroalgae can be detected are usually shallower than the maximum depths where these macroalgae grow. Using multispectral satellite data with high spatial resolution is preferable to using hyperspectral medium resolution data in mapping benthic macroalgal cover in areas where the spatial heterogeneity is very high. In case of a single image and availability of in situ data multispectral sensors with high spatial resolution (QuickBird) can provide more detailed information about the benthic cover than was assumed based on the shape of reflectance spectra of different bottom types and spectral resolution of the sensor. However, lack of in situ data or using of multiple images may complicate the situation. Muutusi põhjataimestiku kooslustes on võimalik kasutada rannikumeres toimuvate keskkonnamuutuste hindamiseks. Uurimaks kaugseire kasutamise võimalusi põhjataimestiku kaardistamisel…
abstract: Benthic algal cover and trends in its changes are indicators of water state in coastal areas. Remote sensing could provide a tool for mapping bottom vegetation if the substrates are spectrally resolvable. We measured reflectance spectra and collected spectral library of typical bottom types of Estonian coastal waters concentrating mainly on red, green, and brown macroalgae. The spectral library together with a bio-optical model allows estimating the suitability of different remote sensing sensors for mapping Baltic Sea bottom types. The modelling results indicate that the maximum depths where hyperspectral remote sensing instruments could potentially detect the spectral differences between the three most typical green, brown and red benthic macroalgae are greater than the depths where the studied algae actually occur in Estonian coastal waters if the sensor’s SNR is better than 1000:1. To some extent it is possible to map green, red and brown algae with multispectral satellite sensors in turbid waters, which optical properties resemble those of the open Baltic Sea, but the depths where the macroalgae can be detected are usually shallower than the maximum depths where these macroalgae grow. Using multispectral satellite data with high spatial resolution is preferable to using hyperspectral medium resolution data in mapping benthic macroalgal cover in areas where the spatial heterogeneity is very high. In case of a single image and availability of in situ data multispectral sensors with high spatial resolution (QuickBird) can provide more detailed information about the benthic cover than was assumed based on the shape of reflectance spectra of different bottom types and spectral resolution of the sensor. However, lack of in situ data or using of multiple images may complicate the situation. Muutusi põhjataimestiku kooslustes on võimalik kasutada rannikumeres toimuvate keskkonnamuutuste hindamiseks. Uurimaks kaugseire kasutamise võimalusi põhjataimestiku kaardistamisel…
author: Vahtmäe, Ele
date published: 2009-05-20T10:53:18Z
date modified: 2026-07-24T06:23:42Z
provider: University of Tartu
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Tartu