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Abbas M, Alameddine I. Predicting water quality variability in a Mediterranean hypereutrophic monomictic reservoir using Sentinel 2 MSI: the importance of considering model functional form. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:923. [PMID: 37410180 DOI: 10.1007/s10661-023-11456-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 06/01/2023] [Indexed: 07/07/2023]
Abstract
Anthropogenic eutrophication is a global environmental problem threatening the ecological functions of many inland freshwaters and diminishing their abilities to meet their designated uses. Water authorities worldwide are being pressed to improve their abilities to monitor, predict, and manage the incidence of harmful algal blooms (HABs). While most water quality management decisions are still based on conventional monitoring programs that lack the needed spatio-temporal resolution for effective lake/reservoir management, recent advances in remote sensing are providing new opportunities towards better understanding water quality variability in these important freshwater systems. This study assessed the potential of using the Sentinel 2 Multispectral Instrument to predict and assess the spatio-temporal variability in the water quality of the Qaraoun Reservoir, a poorly monitored Mediterranean hypereutrophic monomictic reservoir that is subject to extensive periods of HABs. The work first evaluated the ability to transfer and recalibrate previously developed reservoir-specific Landsat 7 and 8 water quality models when used with Sentinel 2 data. The results showed poor transferability between Landsat and Sentinel 2, with most models experiencing a significant drop in their predictive skill even after recalibration. Sentinel 2 models were then developed for the reservoir based on 153 water quality samples collected over 2 years. The models explored different functional forms, including multiple linear regressions (MLR), multivariate adaptive regression splines (MARS), random forests (RF), and support vector regressions (SVR). The results showed that the RF models outperformed their MLR, MARS, and SVR counterparts with regard to predicting chlorophyll-a, total suspended solids, Secchi disk depth, and phycocyanin. The coefficient of determination (R2) for the RF models varied between 85% for TSS up to 95% for SDD. Moreover, the study explored the potential of quantifying cyanotoxin concentrations indirectly from the Sentinel 2 MSI imagery by benefiting from the strong relationship between cyanotoxin levels and chlorophyll-a concentrations.
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Affiliation(s)
- Mohamad Abbas
- Department of Civil and Environmental Engineering, American University of Beirut, Beirut, Lebanon
| | - Ibrahim Alameddine
- Department of Civil and Environmental Engineering, American University of Beirut, Beirut, Lebanon.
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Deutsch ES, Alameddine I. Hindcasting eutrophication and changes in temperature and storage volume in a semi-arid reservoir: a multi-decadal Landsat-based assessment. ENVIRONMENTAL MONITORING AND ASSESSMENT 2018; 191:41. [PMID: 30593606 DOI: 10.1007/s10661-018-7180-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
In situ monitoring of freshwater systems is often constrained by cost and accessibility, particularly in developing countries and in remote areas. Satellite remote sensing is therefore increasingly being integrated with existing in situ water quality monitoring programs. In this study, we use the Landsat TM/ETM+ image record collected between 1984 and 2015 to track temporal changes in trophic status, chlorophyll-a levels, algal bloom incidences, water clarity, water temperature, and reservoir water volume in a poorly monitored hypereutrophic semi-arid reservoir. Historical reservoir water quality data are inferred from calibrated Landsat-based empirical algorithms. The results show that, although the reservoir has existed in a eutrophic to hypereutrophic state over the past 30 years, its water quality has significantly deteriorated in the most recent decade. Mean summer chlorophyll-a concentrations were found to have increased by around 163% between 1984 and 2015, while water clarity dropped by more than 58% over the same period. Statistically significant changes in surface water temperatures were also apparent for the month of August, with a cumulative increase of 1.24 °C over the 31-year study period. The rise in temperature appears to correlate with the incidence of Microcystis blooms observed in the reservoir over the past decade. On the other hand, the water volume in the reservoir was found to have been fairly stable over time, likely as a result of adaptive reservoir management. This study demonstrates the strength of using Landsat data to hindcast and quantify changes in water quality and quantity in poorly monitored freshwater systems.
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Affiliation(s)
- Eliza S Deutsch
- Department of Civil and Environmental Engineering, Maroun Semaan Faculty of Engineering and Architecture, American University of Beirut, Bliss Street, Beirut, Lebanon
| | - Ibrahim Alameddine
- Department of Civil and Environmental Engineering, Maroun Semaan Faculty of Engineering and Architecture, American University of Beirut, Bliss Street, Beirut, Lebanon.
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Deutsch ES, Alameddine I, El-Fadel M. Monitoring water quality in a hypereutrophic reservoir using Landsat ETM+ and OLI sensors: how transferable are the water quality algorithms? ENVIRONMENTAL MONITORING AND ASSESSMENT 2018; 190:141. [PMID: 29450661 DOI: 10.1007/s10661-018-6506-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 01/24/2018] [Indexed: 06/08/2023]
Abstract
The launch of the Landsat 8 in February 2013 extended the life of the Landsat program to over 40 years, increasing the value of using Landsat to monitor long-term changes in the water quality of small lakes and reservoirs, particularly in poorly monitored freshwater systems. Landsat-based water quality hindcasting often incorporate several Landsat sensors in an effort to increase the temporal range of observations; yet the transferability of water quality algorithms across sensors remains poorly examined. In this study, several empirical algorithms were developed to quantify chlorophyll-a, total suspended matter (TSM), and Secchi disk depth (SDD) from surface reflectance measured by Landsat 7 ETM+ and Landsat 8 OLI sensors. Sensor-specific multiple linear regression models were developed by correlating in situ water quality measurements collected from a semi-arid eutrophic reservoir with band ratios from Landsat ETM+ and OLI sensors, along with ancillary data (water temperature and seasonality) representing ecological patterns in algae growth. Overall, ETM+-based models outperformed (adjusted R2 chlorophyll-a = 0.70, TSM = 0.81, SDD = 0.81) their OLI counterparts (adjusted R2 chlorophyll-a = 0.50, TSM = 0.58, SDD = 0.63). Inter-sensor differences were most apparent for algorithms utilizing the Blue spectral band. The inclusion of water temperature and seasonality improved the power of TSM and SDD models.
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Affiliation(s)
- Eliza S Deutsch
- Department of Civil and Environmental Engineering, American University of Beirut, Beirut, Lebanon
| | - Ibrahim Alameddine
- Department of Civil and Environmental Engineering, American University of Beirut, Beirut, Lebanon.
| | - Mutasem El-Fadel
- Department of Civil and Environmental Engineering, American University of Beirut, Beirut, Lebanon
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Wazne M, Korfali S. Spatial and temporal assessment of metal pollution in the sediments of the Qaraoun reservoir, Lebanon. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:7603-7614. [PMID: 26739989 DOI: 10.1007/s11356-015-6022-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 12/23/2015] [Indexed: 06/05/2023]
Abstract
This study reports on metal (Cd, Cr, Cu, Ni, Pb, and Zn) pollution in the sediments of the Qaraoun reservoir over a span period of 9 years (2004, 2008, and 2013) along with key major environmental indicators. This time period corresponds with the onset of the rapid economic and industrial development of the reservoir region. For the first time, this study assessed the degree of environmental pollution by using indices such as enrichment factors (EF), contamination factors (CF), pollution load index (PLI), and geoaccumulation index (I geo). Moreover, sequential extraction was used to study the operationally determined chemical forms of the metals and their spatial and temporal distribution in the sediments. Correlation coefficients were also calculated to delineate the origin and association of the metals. Total metal concentrations and the environmental indices indicated increased pollution with time. Total organic carbon data showed a remarkable and significant increase in the organic fraction in 2013 relative to previous years. The increase in the organic fraction in the sediments was accompanied with a shift in cadmium [Cd] and lead [Pb] fractionation from the carbonate fraction to the organic fraction. The enrichment of the metal in the sediments along with the increased organic content is expected to exacerbate the metal bioavailability in the reservoir.
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Affiliation(s)
- Mahmoud Wazne
- School of Engineering, Lebanese American University, P.O. Box 36, Byblos, Lebanon.
| | - Samira Korfali
- Natural Science Division, Lebanese American University, P.O. Box 13-5053, Chouran, Beirut, Lebanon
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Ammar R, Kazpard V, Wazne M, El Samrani AG, Amacha N, Saad Z, Chou L. Reservoir sediments: a sink or source of chemicals at the surface water-groundwater interface. ENVIRONMENTAL MONITORING AND ASSESSMENT 2015; 187:579. [PMID: 26293891 DOI: 10.1007/s10661-015-4791-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 08/12/2015] [Indexed: 06/04/2023]
Abstract
This study delineates the physical, chemical, and biological effects resulting from anthropogenic and endogenic activities in a sensitive dammed reservoir situated in a semi-arid region. The reservoir is characterized by two major flow regimes: a wet fill hydrologic regime and a dry spill one. A seasonal sampling campaign was carried out over a period of 2 years (2011-2013) where water samples were collected across the water column and from piezometers just outside the perimeter of the reservoir. Similarly, sediments were collected from the corresponding areas beneath the water column. The water samples were analyzed for environmental isotopic ratios, elemental composition, and physical, biological and chemical parameters, whereas the sediment and algal samples were subjected to physical, mineralogical, spectroscopic, and microscopic analyses. This investigation indicated that the dam had resulted in the alteration of the biogeochemical cycle of nutrients as well as the degradation of the sediment and water quality. The hydrological and biogeochemical processes were found to induce vertical downward transport of chemicals towards the fine grained calcareous sediments during the fill mode, whereas the sediments acted as a source of a chemical flux upward through the water column and downward towards the groundwater during the spill mode. The geomorphological characteristics of the reservoir enhanced the strong hydrological connectivity between the surface water and the groundwater where the reservoir responded quickly to natural and anthropogenic changes in the upper watershed. The water and sediments in the sensitive spill mode were of poor quality and should receive more attention due to the potential hazard for the associated hydro-project and the sustainability of the agricultural soil in the long term. Thus, a safe water and sediment management plan should be implemented in order to improve the dam functionality and to safeguard the precious water resources.
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Affiliation(s)
- Rawaa Ammar
- Platform for Research and Analysis in Environmental Sciences, Doctoral School of Science and Technology, Faculty of Sciences, Lebanese University, P.O. Box 5, Campus Rafic Hariri, Hadath-Beirut, Lebanon,
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Fadel A, Lemaire BJ, Atoui A, Vinçon‐Leite B, Amacha N, Slim K, Tassin B. First assessment of the ecological status of
K
araoun reservoir,
L
ebanon. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/lre.12058] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Ali Fadel
- LEESU (UMR MA‐102) Université Paris‐Est Ecole des Ponts ParisTech AgroParisTech Marne‐la‐Vallée France
- Laboratory of Microorganisms and Food Irradiation Lebanese Atomic Energy Commission‐ CNRS Beirut Lebanon
| | - Bruno J. Lemaire
- LEESU (UMR MA‐102) Université Paris‐Est Ecole des Ponts ParisTech AgroParisTech Marne‐la‐Vallée France
- AgroParisTech Paris France
| | - Ali Atoui
- Laboratory of Microorganisms and Food Irradiation Lebanese Atomic Energy Commission‐ CNRS Beirut Lebanon
| | - Brigitte Vinçon‐Leite
- LEESU (UMR MA‐102) Université Paris‐Est Ecole des Ponts ParisTech AgroParisTech Marne‐la‐Vallée France
| | - Nabil Amacha
- Faculty of Science Lebanese University Beirut Lebanon
- Litani River Authority Beirut Lebanon
| | - Kamal Slim
- Laboratory of Microorganisms and Food Irradiation Lebanese Atomic Energy Commission‐ CNRS Beirut Lebanon
- Faculty of Science Lebanese University Beirut Lebanon
| | - Bruno Tassin
- LEESU (UMR MA‐102) Université Paris‐Est Ecole des Ponts ParisTech AgroParisTech Marne‐la‐Vallée France
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Korfali SI, Jurdi MS. Speciation of metals in bed sediments and water of Qaraaoun Reservoir, Lebanon. ENVIRONMENTAL MONITORING AND ASSESSMENT 2011; 178:563-579. [PMID: 20865319 DOI: 10.1007/s10661-010-1713-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 09/06/2010] [Indexed: 05/29/2023]
Abstract
Determination of only total element in sediments does not give an accurate estimate of the likely environmental impacts. Speciation study of metals in sediment provides information on the potential availability of metals (toxic) to biota under various environmental conditions. In water, the toxic metal specie is the free hydrated metal ion. The toxicity of metals depends especially on their chemical forms rather than their total metal content. The present study focuses on Qaraaoun Reservoir, Lebanon. Earlier studies focused only on total metal concentrations in sediment and water. The objective of this study was to determine metal speciation (Fe, Cr, Ni, Zn, Cu, Pb, Cd) in the (operationally defined) sediment chemical fractions and metal speciation in reservoir water. This would reflect on metal bioavailability and toxicity. Water samples and bed sediments were collected from nine sites during the dry season and a sequential chemical fraction scheme was applied to the <75-μm sieve sediment fraction. Metal content in each fraction was determined by the FAAS technique. The data showed that the highest percentages of total metal content in sediment fractions were for: Fe in residual followed by reducible, Cr and Ni in residual and in reducible, Cu in organic followed by exchangeable, Zn in residual and in organic, Pb in organic and carbonate, Cd was mainly in carbonate. Total metal content in water was determined by ICP-MS technique and aqueous metal speciation was predicted using AQUACHEM software interfaced to PHREEQC geochemical computer model. The water speciation data predicted that a high percentage of Pb and Ni were present as carbonate complex species and low percentages as free hydrated ions, highest percentage of Zn as carbonate complex species followed by free hydrated ion, highest percentage of Cd as free hydrated ion followed by carbonate complex species. The sensitivity attempt of free hydrated ion of Ni, Zn, Pb, and Cd in reservoir water revealed dependence of Zn and Cd on pH and alkalinity, while Ni and Pb were only dependent on pH.
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Affiliation(s)
- Samira Ibrahim Korfali
- Natural Science Division, Lebanese American University, PO Box 13-5053, Chouran Beirut: 1102, 2801 Beirut, Lebanon.
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Kang JH, Lee YG, Lee KY, Cha SM, Cho KH, Lee YS, Ki SJ, Yoon IH, Kim KW, Kim JH. Factors affecting metal exchange between sediment and water in an estuarine reservoir: a spatial and seasonal observation. ACTA ACUST UNITED AC 2009; 11:2058-67. [PMID: 19890563 DOI: 10.1039/b910526c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Water quality response in a reservoir has often been assessed using relatively restricted datasets that cannot provide sufficient information, thereby giving rise to a dramatic over- or underestimate of actual figures. In this paper we discuss how the levels of metallic elements between the sediment and overlying water in an estuarine reservoir can be influenced by aquatic parameters in response to spatial and seasonal conditions. To better elucidate the interfacial exchange between sediment and water, statistical analyses are employed to intensive data sets collected from the Yeongsan Reservoir (YSR), Korea, which has undergone widespread deterioration in water quality due to the continuous growth of anthropogenic sources. During three seasonal sampling campaigns, we found that oxygen deficiency at the bottom water layer promotes Fe and Ni accumulation in sediment, likely due to the formation of sulfide and oxide complexes under anoxic and suboxic environments, respectively. In addition, salinity levels as high as 11 per thousand in the bottom water layer during autumn substantially increase the release of Mn, restricting the use of YSR as a primary source of agricultural irrigation water. Although most dissolved metals are at acceptable levels for sustaining aquatic life, it is recommended that for long-term planning the elevated Fe and Mn levels in sediment should be controlled with oxygen deficiency during dry weather to ensure a sustainable water supply or, at a minimum, better coordinated operation of YSR.
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Affiliation(s)
- Joo-Hyon Kang
- Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712, Korea
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