scholarly journals Color, chlorophyll a , and suspended solids effects on Secchi depth in lakes: implications for trophic state assessment

2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Patrick L. Brezonik ◽  
R. William Bouchard ◽  
Jacques C. Finlay ◽  
Claire G. Griffin ◽  
Leif G. Olmanson ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Trophic State ◽  
Suspended Solids ◽  
Secchi Depth ◽  
State Assessment

scholarly journals A Study on Trophic State in Lakes of Dong Da District, Hanoi

2017 ◽  
Vol 33 (4) ◽  
Author(s):  
Nguyen Thi The Nguyen
Keyword(s):  
Chlorophyll A ◽  
Algal Biomass ◽  
Trophic State ◽  
Secchi Depth ◽  
Limiting Factors ◽  
Factors Affecting ◽  
Large Particles ◽  
The Difference ◽  
Time Plot

One of approaches to assessing the condition of lakes is to look at lakes with respect to their primary production or trophic state. Protecting water quality of urban lakes from eutrophication is an important task of all governments. This study presents an analysis of the trophic state in lakes of Dong Da district, Hanoi. The tropic states of the lakes were characterized using the Carlson TSI and the Chlorophyll-a concentrations with the thresholds of US. The deviations of the Secchi depth and total phosphorus indices from the Chlorophyll-a index were used to identify limiting factors affecting to the tropic state of the lakes. It comes to a conclusion that most of the lakes in study area were hypereutrophic or eutrophic in August 2017 and eutrophic or oligotropic in March 2017. It also reveals that phosphorus were not limited factor for algal biomass but some factors such as nitrogen limitation, zooplankton grazing or toxics limit algal biomass. The time plot method suggested that transparency were dominated by non-algal factors such as color or turbidity or where very small particles predominated, whereas the difference plot method revealed that large particles were dominated. Consequently, more studies should be done to look for the real limiting factors and conditions of the lakes.

scholarly journals Prediction of Algal Chlorophyll-a and Water Clarity in Monsoon-Region Reservoir Using Machine Learning Approaches

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 30 ◽  
Author(s):  
Md Mamun ◽  
Jung-Jae Kim ◽  
Md Ashad Alam ◽  
Kwang-Guk An
Keyword(s):  
Chlorophyll A ◽  
Trophic State ◽  
Secchi Depth ◽  
Water Clarity ◽  
Coefficient Of Determination ◽  
Annual Rainfall ◽  
Support Vector ◽  
Chl A ◽  
Svm Model ◽  
Ann Models

The prediction of algal chlorophyll-a and water clarity in lentic ecosystems is a hot issue due to rapid deteriorations of drinking water quality and eutrophication processes. Our key objectives of the study were to predict long-term algal chlorophyll-a and transparency (water clarity), measured as Secchi depth, in spatially heterogeneous and temporally dynamic reservoirs largely influenced by the Asian monsoon during 2000–2017 and then determine the reservoir trophic state using a multiple linear regression (MLR), support vector machine (SVM) and artificial neural network (ANN). We tested the models to analyze the spatial patterns of the riverine zone (Rz), transitional zone (Tz) and lacustrine zone (Lz) and temporal variations of premonsoon, monsoon and postmonsoon. Monthly physicochemical parameters and precipitation data (2000–2017) were used to build up the models of MLR, SVM and ANN and then were confirmed by cross-validation processes. The model of SVM showed better predictive performance than the models of MLR and ANN, in both before validation and after validation. Values of root mean square error (RMSE) and mean absolute error (MAE) were lower in the SVM model, compared to the models of MLR and ANN, indicating that the SVM model has better performance than the MLR and ANN models. The coefficient of determination was higher in the SVM model, compared to the MLR and ANN models. The mean and maximum total suspended solids (TSS), nutrients (total nitrogen (TN) and total phosphorus (TP)), water temperature (WT), conductivity and algal chlorophyll (CHL-a) were in higher concentrations in the riverine zone compared to transitional and lacustrine zone due to surface run-off from the watershed. During the premonsoon and postmonsoon, the average annual rainfall was 59.50 mm and 54.73 mm whereas it was 236.66 mm during the monsoon period. From 2013 to 2017, the trophic state of the reservoir on the basis of CHL-a and SD was from mesotrophic to oligotrophic. Analysis of the importance of input variables indicated that WT, TP, TSS, TN, NP ratios and the rainfall influenced the chlorophyll-a and transparency directly in the reservoir. These findings of the algal chlorophyll-a predictions and Secchi depth may provide key clues for better management strategy in the reservoir.

Total volatile solids may aid in trophic state assessment in subtropical reservoirs

2013 ◽  
Vol 13 (3) ◽  
pp. 808-815
Author(s):  
L. S. F. Pena ◽  
M. d. C. Calijuri ◽  
D. G. F. Cunha
Keyword(s):  
Chlorophyll A ◽  
Trophic State ◽  
State Assessment ◽  
Trophic State Index ◽  
Total Volatile ◽  
Volatile Solids ◽  
Different Depths ◽  
State Index ◽  
Special Concern

Brazilian artificial reservoirs are multi-purpose systems of great importance for the community since they are used for drinking water supply, energy generation and agricultural irrigation. Anthropogenic eutrophication is an environmental problem of special concern because it can restrict water use due to aquatic systems deterioration. Therefore, trophic state prediction is an important tool for the rapid detection of water quality decrease and the identification of priority areas where action is needed. Within this context, the aim of this research was to assess the role of TVS (total volatile solids) in predicting the trophic status of subtropical reservoirs. To achieve this goal, four stations in the Itupararanga Reservoir (São Paulo State, Brazil) were sampled during dry, intermediate and rainy periods to determine total suspended solids concentrations in different depths of the water column, in addition to other variables (e.g. phosphorus, nitrogen, chlorophyll-a). Through a linear regression between TSI (trophic state index) and the TVS concentrations, an equation relating these two variables was generated (R2 = 0.67). New TSI values (named TSIcalc) were calculated and analyzed against the observed ones (TSIobs, determined through the total phosphorus and chlorophyll-a concentrations). The results suggested that TVS may be considered an interesting variable to predict the trophic state of subtropical reservoirs.

APLIKASI CITRA LANDSAT 8 OLI UNTUK IDENTIFIKASI STATUS TROFIK WADUK GAJAH MUNGKUR WONOGIRI, JAWA TENGAH

2017 ◽  
Vol 19 (2) ◽  
pp. 113
Author(s):  
Kusuma Wardani Laksitaningrum ◽  
Wirastuti Widyatmanti
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic State ◽  
Water Clarity ◽  
Coefficient Of Determination ◽  
Physical Factors ◽  
Landsat 8 ◽  
Trophic State Index ◽  
Landsat 8 Oli ◽  
State Index

<p align="center"><strong>ABSTRAK</strong></p><p class="abstrak">Waduk Gajah Mungkur (WGM) adalah bendungan buatan yang memiliki luas genangan maksimum 8800 ha, terletak di Desa Pokoh Kidul, Kecamatan Wonogiri, Kabupaten Wonogiri. Kondisi perairan WGM dipengaruhi oleh faktor klimatologis, fisik, dan aktivitas manusia yang dapat menyumbang nutrisi sehingga mempengaruhi status trofiknya. Tujuan dari penelitian ini adalah mengkaji kemampuan citra Landsat 8 OLI untuk memperoleh parameter-parameter yang digunakan untuk menilai status trofik, menentukan dan memetakan status trofik yang diperoleh dari citra Landsat 8 OLI, dan mengevaluasi hasil pemetaan dan manfaat citra penginderaan jauh untuk identifikasi status trofik WGM. Identifikasi status trofik dilakukan berdasarkan metode <em>Trophic State Index</em> (TSI) Carlson (1997) menggunakan tiga parameter yaitu kejernihan air, total fosfor, dan klorofil-a. Model yang diperoleh berdasar pada rumus empiris dari hasil uji regresi antara pengukuran di lapangan dan nilai piksel di citra Landsat 8 OLI. Model dipilih berdasarkan nilai koefisien determinasi (R<sup>2</sup>) tertinggi. Hasil penelitian merepresentasikan bahwa nilai R<sup>2</sup> kejernihan air sebesar 0,813, total fosfor sebesar 0,268, dan klorofil-a sebesar 0,584. Apabila nilai R<sup>2 </sup>mendekati 1, maka semakin baik model regresi dapat menjelaskan suatu parameter status trofik. Berdasarkan hasil kalkulasi diperoleh distribusi yang terdiri dari kelas eutrofik ringan, eutrofik sedang, dan eutrofik berat yaitu pada rentang nilai indeks 50,051 – 80,180. Distribusi terbesar adalah eutrofik sedang. Hal tersebut menunjukkan tingkat kesuburan perairan yang tinggi dan dapat membahayakan makhluk hidup lain.</p><p><strong>Kata kunci: </strong>Waduk Gajah Mungkur, citra Landsat 8 OLI, regresi, TSI, status trofik</p><p class="judulABS"><strong>ABSTRACT</strong></p><p class="Abstrakeng">Gajah Mungkur Reservoir is an artificial dam that has a maximum inundated areas of 8800 ha, located in Pokoh Kidul Village, Wonogiri Regency. The reservoir’s water conditions are affected by climatological and physical factors, as well as human activities that can contribute to nutrients that affect its trophic state. This study aimed to assess the Landsat 8 OLI capabilities to obtain parameters that are used to determine its trophic state, identifying and mapping the trophic state based on parameters derived from Landsat 8 OLI, and evaluating the results of the mapping and the benefits of remote sensing imagery for identification of its trophic state. Identification of trophic state is based on Trophic State Index (TSI) Carlson (1997), which uses three parameters there are water clarity, total phosphorus, and chlorophyll-a. The model is based on an empirical formula of regression between measurements in the field and the pixel values in Landsat 8 OLI. Model is selected on the highest value towards coefficient of determination (R<sup>2</sup>). The results represented that R<sup>2</sup> of water clarity is 0.813, total phosphorus is 0.268, and chlorophyll-a is 0.584. If R<sup>2</sup> close to 1, regression model will describe the parameters of the trophic state better. Based on the calculation the distribution consists of mild eutrophic, moderate eutrophic, and heavy eutrophic that has index values from 50.051 to 80.18. The most distribution is moderate eutrophication, and it showed the high level of trophic state and may harm other living beings.</p><p><strong><em>Keywords: </em></strong><em>Gajah Mungkur Reservoir, </em><em>L</em><em>andsat 8 OLI satellite imagery, regression, TSI, trophic state</em></p>

Seagrass depth range and water quality in southern Moreton Bay, Queensland, Australia

1996 ◽  
Vol 47 (6) ◽  
pp. 763 ◽  
Author(s):  
EG Abal ◽  
WC Dennison
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Suspended Solids ◽  
Light Attenuation ◽  
River Mouth ◽  
Total Suspended Solids ◽  
Quality Parameters ◽  
Depth Range ◽  
Moreton Bay ◽  
A Site

Correlations between water quality parameters and seagrass depth penetration were developed for use as a biological indicator of integrated light availability and long-term trends in water quality. A year-long water quality monitoring programme in Moreton Bay was coupled with a series of seagrass depth transects. A strong gradient between the western (landward) and eastern (seaward) portions of Moreton Bay was observed in both water quality and seagrass depth range. Higher concentrations of chlorophyll a, total suspended solids, dissolved and total nutrients, and light attenuation coefficients in the water column and correspondingly shallower depth limits of the seagrass Zostera capricorni were observed in the western portions of the bay. Relatively high correlation coefficient values (r2 > 0.8) were observed between light attenuation coefficient, total suspended solids, chlorophyll a, total Kjeldahl nitrogen and Zostera capricorni depth range. Low correlation coefficient values (r2 < 0.8) between seagrass depth range and dissolved inorganic nutrients were observed. Seagrasses had disappeared over a five-year period near the mouth of the Logan River, a turbid river with increased land use in its watershed. At a site 9 km from the river mouth, a significant decrease in seagrass depth range corresponded to higher light attenuation, chlorophyll a, total suspended solids and total nitrogen content relative to a site 21 km from the river mouth. Seagrass depth penetration thus appears to be a sensitive bio-indicator of some water quality parameters, with application for water quality management.

scholarly journals Trophic State Evaluation of Jackson Lake in Grand Teton National Park

1997 ◽  
Vol 21 ◽  
pp. 39-41
Author(s):  
Woodruff Miller
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
National Park ◽  
Trophic State ◽  
Health Department ◽  
Nutrient Concentrations ◽  
Grand Teton National Park ◽  
State Evaluation ◽  
June July

This study is the continuation of an evaluation of the trophic state of lakes located in Grand Teton National Park, Wyoming. The original 1995 study was motivated by concern that the water quality of the lakes within the Park may be declining due to increased human usage over the past several years. A trophic state evaluation, featuring nutrient and chlorophyll-a analyses, was chosen because it is believed to be a sound indicator of the lakes' overall water quality. In this 1996 study, a thorough evaluation was made of Jackson Lake. This summary is taken from the complete 100 page report which is available from Woodruff Miller at Brigham Young University or Hank Harlow at the University of Wyoming. In most cases water samples were taken four times during the summer of 1996, in June, July, August, and October. Jackson Lake was sampled at eight different locations on thesurface and at depths near the bottom. The lake inlet and outlet were also sampled four times. Jackson Lake was sampled from a motor boat which also provided a means to measure the lake transparency and depth. The chlorophyll-a and nutrient concentrations were analyzed by the Utah State Health Department, Division of Laboratory Services. Jackson Lake was evaluated using the models of Carlson, Vollenweider, and Larsen­Mercier. The nature of the Larsen-Mercier and Vollenweider models, based on system inflow and outflow data, is such that they yield one trophic state assessment of the lake per inflow and outflow sample set. The Carlson Trophic State Indices (TSI), on the other hand, are based on in situ properties of the water at any point in the lake. Consequently, while there are four Vollenweider and four Larsen-Mercier evaluations for Jackson Lake, individual Carlson evaluations were made for the eight sample sites around the lake at the surface and at depth, and an evaluation for the lake as a whole was constructed using averages taken from the site evaluations. This allowed us to examine the relative water quality of different portions of the lake at different time periods.

scholarly journals Interannual and long-term changes in the trophic state of a multibasin lake: effects of morphology, climate, winter aeration, and beaver activity

2016 ◽  
Vol 73 (3) ◽  
pp. 445-460 ◽  
Author(s):  
Dale M. Robertson ◽  
William J. Rose ◽  
Paul C. Reneau
Keyword(s):  
Water Quality ◽  
Trophic State ◽  
Secchi Depth ◽  
Climatic Changes ◽  
Main Flow ◽  
Temperature And Precipitation ◽  
Air Temperatures ◽  
Long Term Changes ◽  
P Sources

Little St. Germain Lake (LSG), a relatively pristine multibasin lake in Wisconsin, USA, was examined to determine how morphologic (internal), climatic (external), anthropogenic (winter aeration), and natural (beaver activity) factors affect the trophic state (phosphorus, P; chlorophyll, CHL; and Secchi depth, SD) of each of its basins. Basins intercepting the main flow and external P sources had highest P and CHL and shallowest SD. Internal loading in shallow, polymictic basins caused P and CHL to increase and SD to decrease as summer progressed. Winter aeration used to eliminate winterkill increased summer internal P loading and decreased water quality, while reductions in upstream beaver impoundments had little effect on water quality. Variations in air temperature and precipitation affected each basin differently. Warmer air temperatures increased productivity throughout the lake and decreased clarity in less eutrophic basins. Increased precipitation increased P in the basins intercepting the main flow but had little effect on the isolated deep West Bay. These relations are used to project effects of future climatic changes on LSG and other temperate lakes.

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