scholarly journals Changing Characteristics of Chlorophyll a in the Context of Internal and External Factors: A Case Study of Dianchi Lake in China

2019 ◽  
Vol 11 (24) ◽  
pp. 7242 ◽  
Author(s):  
Pengfei Hou ◽  
Yi Luo ◽  
Kun Yang ◽  
Chunxue Shang ◽  
Xiaolu Zhou

During the past 20 years, the ecological environment of Dianchi Lake has been adversely affected by climate change and human activities, which directly affected the ecosystem and biodiversity of the Dianchi Lake watershed. Analyzing the spatiotemporal variation of chlorophyll a (Chla) concentration of Dianchi Lake and exploring the internal and external factors effect on Chla concentration is the basis for controlling and improving the water ecological environment of Dianchi Lake, and it is also the key to prevent and control the water pollution of Dianchi Lake. In this study, the water quality of Dianchi Lake was examined using 12 water quality indicators from 10 water quality monitoring sites for the duration between 2000 to 2017. The changing characteristics of Chla in the context of internal and external factors were analyzed. The spatiotemporal evolution process of Chla concentration in the past 20 years was also evaluated. The results indicated that Chla concentration was significantly and positively correlated with the chemical oxygen demand (CODCr), the Dianchi Lake watershed gross domestic product (GDP), and the impervious surface area (ISA) of the watershed, in addition to the total phosphorus (TP), biochemical oxygen demand (BOD5), ammonia hydrogen (NH3-N), water temperature (WT), and civil vehicle ownership. Moreover, a significant and negative correlation was noticed between Dianchi Lake watershed GDP and NH3-N, BOD5, TP, total nitrogen (TN), and comprehensive nutrition state index (TLI). The Dianchi Lake population was negatively correlated with TP, TLI, and BOD5. The concentration of Chla in Dianchi Lake was affected by both internal factors, and external factors such as anthropogenic activities, the latter of which was the main cause of the continuous deterioration of the lake water quality.

2019 ◽  
Vol 20 (2) ◽  
pp. 538-549
Author(s):  
Maoqing Duan ◽  
Xia Du ◽  
Wenqi Peng ◽  
Cuiling Jiang ◽  
Shijie Zhang

Abstract In northern China, river water originating from or flowing through forests often contains large amounts of oxygen-consuming organic substances, mainly humic substances. These substances are stable and not easily biodegradable, resulting in very high detection values of chemical oxygen demand. However, under natural conditions, the dissolved oxygen demand is not as high. Using experimental values to evaluate river water quality and the impact of human activities on water quality is thus unscientific and does not meet national development goals. In this study, the potential sources of high-concentration chemical oxygen demand in river water in two areas exposed to virtually no anthropogenic activities and strongly affected by humic substances, were analysed. The chemical oxygen demand contributed by humic substances (COD-HSs) was quantified using three methods. The results of water quality monitoring in 2017 and 2018 revealed that the chemical oxygen demand concentrations (5–44 mg/L) predominantly exceeded the standard (15 mg/L). The study results suggest that COD-HSs should be considered separately for objective evaluation and management of water quality, particularly in areas that are seriously affected by COD-HSs, to provide a scientific basis for formulating sustainable water quality management policies.


2020 ◽  
Vol 32 (4) ◽  
pp. 827-834
Author(s):  
Muhammad Towhid Moula ◽  
Ranjit K. Nath ◽  
Mh. Mosfeka Chowdhury ◽  
Md. Abu Bakar Siddique

Halda is an important river of Bangladesh, is now polluted in different ways through industrial, agricultural, domestic and sewage disposal. Increased anthropogenic activities have increased the potential pollution of the river and excessive pollutants may be toxic to humans and aquatic fauna. Presence of heavy metals in the river water causes perilous impact on the aquatic organisms. Hence, regular monitoring of pollution levels in the river is indispensable. In this study, we discuss about physico-chemical assessments of water quality parameters viz. pH, dissolve oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solid (TS), total suspended solid (TSS), total dissolved substance (TDS), total alkalinity, turbidity, salinity, electrical conductivity (EC), hardness, chloride and heavy metals in the water of Halda river during rainy and winter seasons, at different points; sources of pollutants in water and their effects given starting from the early research until the current research.


2021 ◽  
Vol 934 (1) ◽  
pp. 012059
Author(s):  
A M S Hertika ◽  
D Arfiati ◽  
E D Lusiana ◽  
R B D S Putra ◽  
D R N Wasti

Abstract Anthropogenic activities along watershed area are often causing river pollution. This will affect the sustainability of aquatic resources, such as fish. One of the fish species in Brantas River that can be employed as bioindicator of water pollution is Wader fish (Puntius, sp.). The aim of this research was to analyze the health of Wader fish based on tits hematological profile. This study utilized descriptive method and conducted in three sites of Brantas River that located in Malang city, Indonesia. We took water quality parameters data to obtain Pollution Index of the river and blood samples to evaluate the hematological profile of wader fish caught in research area. Further analysis to evaluate relationship between water quality factors and hematological profile of Wader fish was performed by using Canonical Correspondence Analysis (CCA) with the support of PAST software version 4.06. The results showed that pH, temperature, dissolved oxygen (DO), ammonia and total suspended solid (TSS) of the study area were within the normal range, while the biological oxygen demand (BOD) value was above the standard. In addition, Pollution Index of this research suggested that Brantas River condition was low polluted. Meanwhile, the analysis of hematological profile of wader fish in terms of erythrocytes and hemoglobin were below than the recommended value, leukocytes were normal, and micronuclei were above the standard.


Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 375
Author(s):  
Cheng He ◽  
Youru Yao ◽  
Xiaoman Lu ◽  
Mingnan Chen ◽  
Weichun Ma ◽  
...  

In estuary areas, meteorological conditions have become unstable under the continuous effects of climate change, and the ecological backgrounds of such areas have strongly been influenced by anthropic activities. Consequently, the water quality of these areas is obviously affected. In this research, we identified periods of fluctuation of the general meteorological conditions in the Yangtze River Estuary using a wavelet analysis. Additionally, we performed a spatiotemporal evaluation of the water quality in the fluctuating period by using remote sensing modeling. Then, we explored how the fluctuating meteorological factors affect the distribution of total suspended solids (TSS) and chlorophyll-a (Chla) concentration. (1) The results show that from 2000 to 2015, temperature did not present significant fluctuations, while wind speed (WS) and precipitation (PR) presented the same fluctuation period from January 2012 to December 2012. (2) Based on the measured water sample data associated with Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, we developed a water quality algorithm and depicted the TSS and Chla concentrations within the WS and PR fluctuating period. (3) We found that the TSS concentration decreased with distance from the shore, while the Chla concentration showed an initially decreasing trend followed by an increasing trend; moreover, these two water quality parameters presented different inter-annual variations. Then, we discussed the correlation between the changes in the TSS and Chla concentrations and the WS and PR variables. The contribution of this research is reflected in two aspects: 1. variations in water quality parameters over a wide range of water bodies can be evaluated based on MODIS data; 2. data from different time periods showed that the fluctuations of meteorological elements had different impacts on water bodies based on the distance from the shore. The results provide new insights for the management of estuary water environments.


2021 ◽  
Vol 13 (14) ◽  
pp. 2821
Author(s):  
Runfei Zhang ◽  
Zhubin Zheng ◽  
Ge Liu ◽  
Chenggong Du ◽  
Chao Du ◽  
...  

The chlorophyll-a (Chl-a) concentration of eutrophic lakes fluctuates significantly due to the disturbance of wind and anthropogenic activities on the water body. Consequently, estimation of the Chl-a concentration has become an immense challenge. Due to urgent demand and rapid development in high-resolution earth observation systems, it has become crucial to assess hyperspectral satellite imagery capabilities on inland water monitoring. The Orbita hyperspectral (OHS) satellite is the latest hyperspectral sensor with both high spectral and spatial resolution (2.5 nm and 10 m, respectively), which could provide great potential for remotely estimating the concentration of Chl-a for inland waters. However, there are still some deficiencies that are mainly manifested in the Chl-a concentration remote sensing retrieval model assessment and accuracy validation, as well as signal-to-noise ratio (SNR) estimation of OHS imagery for inland waters. Therefore, the radiometric performance of OHS imagery for water quality monitoring is evaluated in this study by comparing different atmospheric correction models and the SNR with several remote sensing images. Several crucial findings can be drawn: (1) the three-band model ((1/B15-1/B17)B19) developed by OHS imagery is most suitable for estimating the Chl-a concentration in Dianchi Lake, with the root-mean-square error (RMSE) and the mean absolute percentage error (MAPE) of 15.55 µg/L and 16.31%, respectively; (2) the applicability of the FLAASH (Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes) atmospheric correction model for OHS imagery in a eutrophic plateau lake (Dianchi Lake) was better than the 6S (Second Simulation of Satellite Signal in the Solar Spectrum) model, and QUAC (Quick Atmospheric Correction) model, as well as the dark pixel method; (3) the SNR of the OHS imagery was similar to that of Hyperion imagery and was significantly higher than SNR of the HSI imagery; (4) the spatial resolution showed slight influence on the SNR of the OHS imagery. The results show that OHS imagery could be applied to remote sensing retrieval of Chl-a in eutrophic plateau lakes and presents a new tool for dynamic hyperspectral monitoring of water quality.


Author(s):  
Jingjing Xia ◽  
Jin Zeng

In order to meet people's increasing demands for a better life and beautiful ecological environment, the control efforts of environmental pollution have increased significantly. Water quality eutrophication has become one...


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Teck-Yee Ling ◽  
Chen-Lin Soo ◽  
Jing-Jing Liew ◽  
Lee Nyanti ◽  
Siong-Fong Sim ◽  
...  

The present study evaluated the spatial variations of surface water quality in a tropical river using multivariate statistical techniques, including cluster analysis (CA) and principal component analysis (PCA). Twenty physicochemical parameters were measured at 30 stations along the Batang Baram and its tributaries. The water quality of the Batang Baram was categorized as “slightly polluted” where the chemical oxygen demand and total suspended solids were the most deteriorated parameters. The CA grouped the 30 stations into four clusters which shared similar characteristics within the same cluster, representing the upstream, middle, and downstream regions of the main river and the tributaries from the middle to downstream regions of the river. The PCA has determined a reduced number of six principal components that explained 83.6% of the data set variance. The first PC indicated that the total suspended solids, turbidity, and hydrogen sulphide were the dominant polluting factors which is attributed to the logging activities, followed by the five-day biochemical oxygen demand, total phosphorus, organic nitrogen, and nitrate-nitrogen in the second PC which are related to the discharges from domestic wastewater. The components also imply that logging activities are the major anthropogenic activities responsible for water quality variations in the Batang Baram when compared to the domestic wastewater discharge.


Author(s):  
Andrio Adwibowo

The COVID 19 related social distancing is hypothesized can affect the environmental quality including the air and water quality. Correspondingly, this study aims to study how the reduction of activities of people living near the rivers and the coastal areas due to social distancing may decrease the discharges of materials and nutrients to the water body. The chlorophyll-a was used as bio indicators of nutrient contents related to the anthropogenic activities in the coast. The study was conducted in the Jakarta coast considering that this coast was surrounded by populated cities with total population equal to 16 million people. The chlorophyll-a was measured in mg/m3 and monitored using remote sensing data from January to April 2020 representing the period before and after the implementation of social distancing. The determinant environmental factor measured was sea surface temperature (0C). The study considered that there were reductions of levels and areas of chlorophyll-a in the coast. The chlorophyll-a levels were reduced from January to April (p<0.05). The chlorophyll-a levels for January, February, March, and April were 7.36 mg/m3 (95%CI: 6.34-8.37), 7.90 mg/m3 (95%CI: 7.32-8.47), 6.52 mg/m3 (95%CI: 5.37-7.66), and 4.21 mg/m3 (95%CI: 3.34-5.07) respectively. However, the differences of chlorophyll-a were not influenced by the sea surface temperature factor (p>0.05). Based on remote sensing data in January and February, the sizes of coastal areas with chlorophyll-a levels >7.00 mg/m3 were larger than areas observed in March and April. Contrarily, the coastal area sizes with low chlorophyll-a levels <5.00 mg/m3 were increasing in April. To conclude the dynamic of anthropogenic activities in coastal setting is responsible and associated with the water quality and nutrient contents as indicated by chlorophyll-a levels.


Author(s):  
G. B. Bate ◽  
N. O. Sam-Uket

A study was undertaken to determine the macroinvertebrates pollution tolerance index (PTI) in Calabar River, Cross River state, Nigeria. Five sampling stations were chosen along the river course: Ikot Okon Abasi, Tinapa, Unicem, Marina resort and Nsidung beach which were labeled stations 1, 2, 3, 4 and 5 respectively. Physico-chemical parameters; surface water temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), total dissolved solids (TDS) and total suspended solids (TSS) were measured using their respective meters while macroinvertebrates were sampled using a Van Veen grab, stained with Rose Bengal solution and identified under microscope. Macroinvertebrates pollution tolerance index was obtained using online software designed by Northern Kentucky Univeristy and Leaf Pack Network Biotic and Water Quality Calculator. The results obtained for physicochemical parameters showed the highest temperature as 29.90C in station five while the lowest was 26.40C in station one. pH was highest (6.60) in station five and lowest (5.52) in station one. DO was highest (4.4mg/L) in station four and lowest (3.0 mg/L) in station five while BOD was highest (3.2 mg/L) in station three and lowest (0.3 mg/L) in station one. An average total of 5366 macroinvertebrate individuals were encountered belonging to nine families and eleven species. Tubificidae had the lowest occurrence with 18 individuals which made up 0.3% of the total macroinvertebrates while Penaeidae had the highest occurrence with 2,455 individuals constituting 45.8% of the total count. Pollution tolerance index was highest (21) in station five and lowest (9) in station four with the water quality being generally poor. Hence, it is suggested that anthropogenic activities should be regulated and continuous monitoring of the river course should be carried out.


2019 ◽  
Vol 11 (4) ◽  
pp. 104-121
Author(s):  
Melissa Arantes Pinto ◽  
Vitoria Marta Venancio Rodrigues ◽  
Bianca Soares de Souza ◽  
Yeda Ruiz Maria ◽  
Elson Mendonca Felici ◽  
...  

The environmental diagnosis of the tributaries of the Lajeado Stream tributaries in Pirapozinho / SP is a study that will evaluate the characteristics of the natural environment, as well as the interactions and interferences caused by anthropogenic activities in the environment and the impacts resulting from these actions. This characterization will be done through visual on-site surveys, laboratory analysis and literature searches that allow a better understanding of the behavior of a watershed in face of external factors. In this sense, we evaluate procedures such as soil use and occupation, water quality, environmental valuation, development of vegetative areas, soil qualification, among other aspects. Thus, the interpretation of the quality of the natural resources raised and their interference will support an assessment of which identified impacts are likely to be mitigated in order to employ the necessary recovery and improvement technologies in the area.


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