scholarly journals Seasonal and Long-Term Connections between Trophic Status, Sestonic Chlorophyll, Nutrients, Organic Matter, and Monsoon Rainfall in a Multipurpose Reservoir

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1720
Author(s):  
Namsrai Jargal ◽  
Usman Atique ◽  
Md Mamun ◽  
Kwang-Guk An

Due to rapid eutrophication, sustainable water quality management and supply are essential in drinking water sources and aquatic biota in large reservoirs. We evaluated the potentially crucial factors influencing the algal chlorophyll (CHL-a), nutrients, and the links between the rainfall and other vital elements in a large multipurpose reservoir (Yongdam Reservoir) during 2013–2019. We developed the empirical models on algal CHL-a, total phosphorus (TP), total nitrogen (TN), and TN:TP’s ambient ratios considering the maneuvering influence of Asian monsoons. The intensive rainfall during the monsoon months strongly impacted the nutrient regime and other vital factors. The seasonal patterns of algal CHL-a varied in response to the nutrient contents (TN, TP), suspended solids, and ambient N:P ratios along the longitudinal gradient. The conditional plot analysis, empirical modeling, and observations supported an overall P-limitation scenario, as was evident from the magnitude of N:P ratios (R2 = 0.36, F = 24.9, p < 0.001). Furthermore, the reservoir’s trophic status alluded to the larger particles and blue-green algae during the monsoon and postmonsoon months. The correlation analysis, Mann–Kendall trend test, and principal component analysis illustrated compelling links between CHL-a, TP, and rainfall regime. The outcomes suggested the reservoir was primarily controlled by phosphorus limitation, with an increasing CHL-a tendency along with nitrogen dilution. However, a slight decline in phosphorus was also detected. The Yongdam Reservoir is under the threat of recurrent eutrophication events that could jeopardize this vital drinking water facility due to increasing agricultural and anthropic activities.

2021 ◽  
Author(s):  
xuemei fu ◽  
Mingxia Zheng ◽  
Jing Su ◽  
Beidou Xi ◽  
Daichun Wu ◽  
...  

Abstract Chlorophyll-a (Chl- a ) is considered an indicator of phytoplankton biomass dynamically reflecting the growth of algae. Therefore, determination of Chl- a threshold is of vital importance to the health of aquatic ecosystems and drinking water security. This research is aimed to investigate the spatial and temporal distributions of Chl- a and microcystin (MC) concentrations using Geographic Information System (GIS) and identify the Chl- a threshold in Lake Taihu based on available guideline values of MCs. Nearly the same characteristics of spatiotemporal variation of Chl- a and MCs were observed in Lake Taihu. Overall, the lakewide distributions of Chl- a and MCs were highly variable over time and space. The Chl- a concentration in the winter and spring was relatively low, and gradually increasing in summer and autumn, with the maximum concentration observed in August. But the maximum MCs concentration appeared in October, two months lagging behind the Chl- a . The highest annual average Chl- a and MCs concentrations were observed in Zhushan Bay, Meiliang Bay, Gonghu Bay in northwest of Lake Taihu, following by West Zone and Center Zone. Dongtaihu Bay, East Zone and South Zone always present good water quality. Referring to the guideline value of MCs, the Chl- a threshold was determined as 10-15 mg·m -3 based on the linear regression correlation between Chl- a and MCs. The establishment of Chl- a threshold is useful for eutrophication control, water quality management and drinking water utilities in developing water safety plans.


Author(s):  
Angelica M. Moncada ◽  
Assefa M. Melesse ◽  
Jagath Vithanage ◽  
René M. Price

Anthropogenic developments in coastal watersheds cause significant ecological changes to estuaries. Since estuaries respond to inputs on relatively long time scales, robust analyses of long-term data should be employed to account for seasonality, internal cycling, and climatological cycles. This study characterizes the water quality of a highly managed coastal basin, the St. Lucie Estuary Basin, FL, USA, from 1999 to 2019 to detect spatiotemporal differences in the estuary’s water quality and its tributaries. The estuary is artificially connected to Lake Okeechobee, so it receives fresh water from an external basin. Monthly water samples collected from November 1999 to October 2019 were assessed using principal component analysis, correlation analysis, and the Seasonal Kendall trend test. Nitrogen, phosphorus, color, total suspended solids, and turbidity concentrations varied seasonally and spatially. Inflows from Lake Okeechobee were characterized by high turbidity, while higher phosphorus concentrations characterized inflows from tributaries within the basin. Differences among tributaries within the basin may be attributed to flow regimes (e.g., significant releases vs. steady flow) and land use (e.g., pasture vs. row crops). Decreasing trends for orthophosphate, total phosphorus, and color and increasing trends for dissolved oxygen were found over the long term. Decreases in nutrient concentrations over time could be due to local mitigation efforts. Understanding the differences in water quality between the tributaries of the St. Lucie Estuary is essential for the overall water quality management of the estuary.


2015 ◽  
Vol 2015 (2) ◽  
pp. 1-9 ◽  
Author(s):  
Carla Cherchi ◽  
Mohammad Badruzzaman ◽  
Joan Oppenheimer ◽  
Matthew Gordon ◽  
Simon Bunn ◽  
...  

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Abdulqadir Abubakar Usman ◽  
Murtala Abubakar Gada ◽  
Aminu Muhammad Bayawa ◽  
Ibrahim Mustapha Dankani ◽  
Saadu Umar Wali

This study examined the hydrochemistry of surface water along the River-Rima floodplain area. Five sampling locations were purposively selected, and, in each point, three samples were taken from surface water (river). The sampling was repeated after 20 days. Thus, a total of 30 samples were collected. Water samples obtained were subjected to laboratory tests. Results revealed that BOD, TDS, Mg2+, and Fe3+ are above the World Health Organization (WHO) and Standard Organization of Nigeria (SON) reference guidelines for drinking water quality. Isolates detected from the coliform bacteriological analysis include Enterobacter aerogene, Escherichia coli, and Citrobacter freundii with most of the samples showing coliform bacteria growth above the SON standard for drinking water. Hence, the water in the River-Rima floodplain of the Wamakko area is of low quality and unsafe for drinking. Results of principal component analysis (PCA) revealed external influences such as pollutant wash off and rock weathering as controls on hydrochemistry of surface water. There is some indication of anthropogenic inputs (Cl-, NO3-, and PO42-) based on hierarchical cluster analysis. Elements including Cl-, NO3-, and PO42- are increasingly added into surface water from human activities, mainly agriculture, and municipal sewage.


2021 ◽  
Vol 10 (1) ◽  
pp. 49-63
Author(s):  
Hefdhallah Al Aizari ◽  
Rachida Fegrouche ◽  
Ali Al Aizari ◽  
Saeed S. Albaseer

The fact that groundwater is the only source of drinking water in Yemen mandates strict monitoring of its quality. The aim of this study was to measure the levels of fluoride in the groundwater resources of Dhamar city. Dhamar city is the capital of Dhamar governorate located in the central plateau of Yemen. For this purpose, fluoride content in the groundwater from 16 wells located around Dhamar city was measured. The results showed that 75% of the investigated wells contain fluoride at or below the permissible level set by the World Health Organization (0.5 – 1.5 mg/L), whereas 25% of the wells have relatively higher fluoride concentrations (1.59 – 184 mg/L). The high levels of fluoride have been attributed to the anthropogenic activities in the residential areas near the contaminated wells. Interestingly, some wells contain very low fluoride concentrations (0.30 – 0.50 mg/L).  Data were statistically treated using the principal component analysis (PCA) method to investigate any possible correlations between various factors. PCA shows a high correlation between well depth and its content of fluoride. On the other hand, health problems dominating in the study area necessitate further studies to investigate any correlation with imbalanced fluoride intake.


2019 ◽  
Vol 10 (3) ◽  
pp. 197
Author(s):  
Siti Nurul Aida ◽  
Agus Djoko Utomo

Waduk Pondok seluas 407 Ha berada di Ngawi Jawa Timur, beroperasi sejak 1995 dan merupakan waduk serbaguna. Kegiatan budidaya ikan dengan keramba jaring apung (KJA) di Waduk tersebut sudah berkembang, hingga mencapai 126 petak pada tahun 2016. Penelitian ini bertujuan untuk menganalisis tingkat kesuburan perairan, total fosfor yang terlepas dari KJA ke peraian dan mengestimasi daya dukung perairan untuk KJA. Tingkat kesuburan perairan dianalisa dengan nilai index status trofik (TSI). Estimasi daya dukung perairan untuk KJA menggunakan pendekatan model keseimbangan total fosfor (P) yang terlepas ke parairan. Hasil penelitian menunjukkan bahwa perairan waduk Pondok sudah termasuk dalam katagori perairan eutrofik dengan nilai TSI 62,1.Total P yang terlepas ke perairan sebesar 15,04 kg ton ikan. Daya dukung perairan untuk KJA adalah 195,2 ton /tahun (130 petak KJA). Jumlah KJA di Waduk Pondok ada 126 petak (189 ton) atau sudah mendekati daya dukung perairan, sehingga jumlahnya tidak dapat ditambah lagi.Pondok Reservoir as large as 407 hectares is located in Ngawi, East Java. The Reservoir was functionally started in 1995, is a multipurpose reservoir. Fish culture in Pondok Reservoir in 2016 reached 126 cages. The aim of this research is to evaluate the trophic status, the total of phosphorus released into the waters from floating net cage, and carrying capacity of the reservoir for fish culture. Trophic status of reservoir was analyzed trough calculating the TSI (Trophic Status Index). A phosphorus mass balance model was used in assessing the carrying capacity of the reservoir. Research hypotesis in this research is Pondok reservoir has reached eutrophic status, and cages number in Pondok reservoir has alreday exceeds carriying capacity. Pondok reservoir have been categorized as eutrophic status, with the value of TSI 62.1. Total P released to the waters is 15.04 kg P / ton of fish. The carrying capacity of Pondok Reservoir for fish culture is 195,2 ton / year (130 cages). The number fish culture in Pondok Reservoir is 126 cages (189 ton), has already approaching maximum number can not be added anymore.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jin Jing ◽  
Qian Hui ◽  
Chen Yu-Fei ◽  
Xi Wen-Juan

The basic theory and calculating processes of matter element extension method are discussed in detail. Mass balance simulation is used to study the changes of groundwater chemistry. Results show that calcite and dolomite are oversaturated, while gypsum, fluorite, and halite are unsaturated in the simulation path; so calcite precipitates, while gypsum, fluorite, halite, and dolomite dissolve. The changing tendency of Ca2+/Na+is apparent. Because of the dissolution and precipitation of minerals, the content of each ion changes. Parameters of groundwater are basically within the permissible limits and meet the requirement of drinking water standards. By comparing the evaluation results obtained from matter element extension method, osculating value method based on entropy weight, and principal component analysis method, it is proved that matter element extension is an effective and reasonable method for groundwater quality assessment. The converting tendency of groundwater quality is judged based on the extension indexes; this characteristic is unique of matter element extension method.


Author(s):  
Petr Praus

In this chapter the principals and applications of principal component analysis (PCA) applied on hydrological data are presented. Four case studies showed the possibility of PCA to obtain information about wastewater treatment process, drinking water quality in a city network and to find similarities in the data sets of ground water quality results and water-related images. In the first case study, the composition of raw and cleaned wastewater was characterised and its temporal changes were displayed. In the second case study, drinking water samples were divided into clusters in consistency with their sampling localities. In the case study III, the similar samples of ground water were recognised by the calculation of cosine similarity, the Euclidean and Manhattan distances. In the case study IV, 32 water-related images were transformed into a large image matrix whose dimensionality was reduced by PCA. The images were clustered using the PCA scatter plots.


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