A Comprehensive Review on Water Quality Parameters Estimation Using Remote Sensing Techniques

Remotely sensed data can reinforce the abilities of water resources researchers and decision makers to monitor waterbodies more effectively. Remote sensing techniques have been widely used to measure the qualitative parameters of waterbodies (i.e., suspended sediments, colored dissolved organic matter (CDOM), chlorophyll-a, and pollutants). A large number of different sensors on board various satellites and other platforms, such as airplanes, are currently used to measure the amount of radiation at different wavelengths reflected from the water’s surface. In this review paper, various properties (spectral, spatial and temporal, etc.) of the more commonly employed spaceborne and airborne sensors are tabulated to be used as a sensor selection guide. Furthermore, this paper investigates the commonly used approaches and sensors employed in evaluating and quantifying the eleven water quality parameters. The parameters include: chlorophyll-a (chl-a), colored dissolved organic matters (CDOM), Secchi disk depth (SDD), turbidity, total suspended sediments (TSS), water temperature (WT), total phosphorus (TP), sea surface salinity (SSS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chemical oxygen demand (COD)

Water Quality Modelling Using Multivariate Statistical Analysis and Remote Sensing in South Florida

The overall objective of this dissertation research is to understand the spatiotemporal dynamics of water quality parameters in different water bodies of South Florida. Two major approaches (multivariate statistical techniques and remote sensing) were used in this study. Multivariate statistical techniques include cluster analysis (CA), principal component analysis (PCA), factor analysis (FA), discriminant analysis (DA), absolute principal component score-multiple linear regression (APCS-MLR) and PMF receptor modeling techniques were used to assess the water quality and identify and quantify the potential pollution sources affecting the water quality of three major rivers of South Florida. For this purpose, a 15-year (2000–2014) data set of 12 water quality variables, and about 35,000 observations were used. Agglomerative hierarchical CA grouped 16 monitoring sites into three groups (low pollution, moderate pollution, and high pollution) based on their similarity of water quality characteristics. DA, as an important data reduction method, was used to assess the water pollution status and analysis of its spatiotemporal variation. PCA/FA identified potential pollution sources in wet and dry seasons, respectively, and the effective mechanisms, rules, and causes were explained. The APCS-MLR and PMF models apportioned their contributions to each water quality variable. Also, the bio-physical parameters associated with the water quality of the two important water bodies of Lake Okeechobee and Florida Bay were investigated based on remotely sensed data. The principal objective of this part of the study is to monitor and assess the spatial and temporal changes of water quality using the application of integrated remote sensing, GIS data, and statistical techniques. The optical bands in the region from blue to near infrared and all the possible band ratios were used to explore the relation between the reflectance of a waterbody and observed data. The developed MLR models appeared to be promising for monitoring and predicting the spatiotemporal dynamics of optically active and inactive water quality characteristics in Lake Okeechobee and Florida Bay. It is believed that the results of this study could be very useful to local authorities for the control and management of pollution and better protection of water quality in the most important water bodies of South Florida

Avaliação do desempenho de algoritmos de sensores remotos para estimativa da clorofila-a e coeficiente de atenuação da luz na água na reserva biológica marinha do Arvoredo (sc) e entorno

TCC(graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Físicas e Matemáticas. OceanografiaA oceanografia por satélites tem avançado bastante nas últimas décadas, e sua grande vantagem é a possibilidade de monitorar mudanças temporais que ocorrem na superfície do oceano com uma abrangência espacial muito maior do que as amostragens tradicionais feitas em cruzeiros oceanográficos. Entre os parâmetros possíveis de se monitorar através de imagens obtidas por sensores remotos está a concentração de clorofila-a, de grande interesse em estudos relacionados à produção primária marinha e ecologia de comunidades marinhas. Os algoritmos globais disponíveis para a estimativa de clorofila-a são obtidos a partir de uma grande quantidade de dados in situ, num amplo intervalo de concentrações, e em diversas regiões do globo, de forma que, muitas vezes, não apresentam boa acurácia em estudos regionais, sendo assim necessários ajustes ou desenvolvimento de algoritmos regionais específicos para cada região. O mesmo ocorre para outro parâmetro, o coeficiente de atenuação da luz na água (Kd490), que é um indicador para a profundidade de penetração da luz na água e consequentemente a quantidade de luz disponível para a fotossíntese, e pode ser correlacionado à medida de disco de Secchi, tão comumente utilizada. Em ambos os casos é necessário correlacionar dados obtidos in situ através de cruzeiros oceanográficos com os dados obtidos a partir das imagens de satélite adquiridas nos mesmos dias e na mesma localização. Na região estudada temos uma grande influência de águas continentais, ricas em material em suspensão e matéria orgânica dissolvida, que são componentes oticamente ativos na água que contribuem para a resposta espectral da água medida pelos sensores e podem diminuir a acurácia dos algoritmos. Utilizando os algoritmos padrão dos sensores MODIS e VIIRS para estimativa de clorofila-a (OC3M e OC3V) e para o coeficiente de atenuação da luz na região da REBIO marinha do Arvoredo com as janelas temporais de 24 h e 12 h, foi encontrado para o sensor MODIS um r² igual a 0,48 e 0,58, respectivamente, para a clorofila-a, e igual a 0,45 e 0,56, respectivamente, para o coeficiente de atenuação da luz na água. Com as janelas temporais de 24 h e 12 h para o sensor VIIRS, foi encontrado um r² igual a 0,58 e 0,65, respectivamente, para a clorofila-a, e igual a 0,58 e 0,80, respectivamente, para o coeficiente de atenuação da luz na água. O sensor VIIRS mostrou um melhor desempenho em relação ao MODIS, constituindo uma boa ferramenta para o monitoramento destes parâmetros do ecossistema na qual a REBIO do Arvoredo está inserida

Ocean colour remote sensing of the Great Barrier Reef waters

The research undertaken has developed relationships between the concentrations of optically-significant substances (phytoplankton, Colour Dissolved Organic Matter (CDOM), and particulates) found in Great Barrier Reef waters and their respective inherent optical properties. Based on this knowledge, a physics-based spectral deconvolution routine was developed that successfully retrieved the concentrations of these substances from passive ocean colour observations such as those from the MODIS imaging satellite

Uncertainty in Hyperspectral Remote Sensing: Analysis of the Potential and Limitation of Shallow Water Bathymetry and Benthic Classification

Propagating the inherent uncertainty in hyperspectral remote sensing is key in understanding the limitation and potential of derived bathymetry and benthic classification. Using an improved optimisation algorithm, the potential of detecting temporal bathymetric changes above uncertainty was quantified from a time series of hyperspectral imagery. A new processing approach was also developed that assessed the limitations and potential of benthic classification by analysing optical separability of substrates above total system uncertainty and attenuating water column

Yellow Matters : Improving the remote sensing of Coloured Dissolved Organic Matter in inland freshwaters

Vellinga, P. [Promotor]Salomons, W. [Promotor]Peters, S.W.M. [Copromotor]Dekker, A.G. [Copromotor

Monitoring chlorophyll-a with remote sensing techniques in the Tagus Estuary

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Gestão e Sistemas AmbientaisEstuaries are transitional ecosystems with high temporal and spatial variability and suffer high anthropogenic pressures. At the present there is a major challenge to monitor these systems in a robust, frequent, systematic and accurate fashion. With the implementation of the Water Framework Directive (WFD), the EU Member States must monitor regularly the most relevant physical and biological parameters. Estuarine information is attained using in-situ samples, model analysis and/or remote sensing data. This work assessed the applicability and accuracy of chlorophyll-a products from the MODIS sensor in the Tagus estuary, comparing them (2000-2002) with simulations of an ecological model, the EcoWin2000. The latter was previously calibrated (1998 & 1999) and validated(2000). It is proposed a conceptual and methodological framework for future monitoring of the estuary using remote sensing data. In a first stage, in the year 2000, typical Case 1 algorithms were pre-assessed and Case 2 algorithms were regionally calibrated. The GSM and Clark algorithms had the best performances, with errors of approximately of 1.1 μg chl-a l-1 (or 20%) and correlations ranging 0.4-0.5. During calibration, the ratio R678/R551 had a good correlation (r = 0.83) and low errors (~1μg chl-a l-1). Its evaluation in 2002, showed low and sometimes negative correlations, with errors of about 2 μg chl-a l-1. In agreement with the preliminary assessment,in 2002, the GSM algorithm had the best correlation (r~0.50) and errors of approximately 0.8μg chl-a l-1. The reliability of remote sensing is higher in the Spring and Summer, and spatially, in the wider mid estuary sections. Although remote sensing needs extensive further development, it was proven to be a reliable tool with several advantages for systematic chl-a monitoring in the Tagus estuary. Specifically, it is a tool with high to assist the EU Member States to accomplish the WFD objectives

Earth resources: A continuing bibliography with indexes (issue 61)

This bibliography lists 606 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1 and March 31, 1989. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, oceanography and marine resources, hydrology and water management, data processing and distribution systems, and instrumentation and sensors, and economic analysis