Environmental factors assisted chlorophyll-a prediction and water quality eutrophication grade classification: A comparative analysis of multiple hybrid models based on SVM

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...

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.


Author(s):  
L.Z. Khalishkhova ◽  
◽  
A. Kh. Temrokova ◽  
I.R. Guchapsheva ◽  
K.A. Bogаtyreva ◽  
...  

Ensuring the sustainable development of agroecosystems requires research into the justification of the impact of environmental factors on the formation of territorial agroecosystems and identifies ways to take them into account in order to justify management decisions and ensure environmental safety. The main goal of the research within the article is to identify the most significant environmental factors in predicting the formation of agroecosystems. Provisions are devoted to the study of the laws governing the functioning of agroecosystems in order to increase their stability. The methods of comparative analysis, generalization, abstraction, logical analysis are applied. A number of provisions are formulated regarding ways to account for the influence of factors on the formation of key elements of agroecosystems.


Our Nature ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 48-54
Author(s):  
Ram Bhajan Mandal ◽  
Sunila Rai ◽  
Madhav Kumar Shrestha ◽  
Dilip Kumar Jha ◽  
Narayan Prasad Pandit

An experiment was carried to assess the effect of red algal bloom on growth and production of carp, water quality and profit from carp for 120 days at Aquaculture Farm of Agriculture and Forestry University, Chitwan. The experiment included two treatments: carp polyculture in non-red pond and carp polyculture in red pond with algal bloom each with three replicates. Carp fingerlings were stocked at 1 fish/m2 and fed with pellet containing 24% CP at 3% body weight. Net yield of rohu was found significantly higher (p<0.05) in non-red ponds (0.38±0.01 t ha-1) than red ponds (0.24±0.05 t ha-1). Survival of rohu (84.9±1.4%), bighead (95.2±2.0%) and mrigal (88.1±14.4%) were also significantly higher (p<0.05) in non-red ponds than red ponds. Red algal bloom affected DO, nitrate and chlorophyll-a, nitrite, total nitrogen, total phosphorus, total dissolved solids and conductivity. However, overall carp production and profit from carp remained unaffected.


1996 ◽  
Vol 47 (6) ◽  
pp. 763 ◽  
Author(s):  
EG Abal ◽  
WC Dennison

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.


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 749
Author(s):  
Yuan Gao ◽  
Zini Lai ◽  
Chao Wang ◽  
Haiyan Li ◽  
Yongzhan Mai

Water pollution can be monitored through the use of indicator species, including Brachionus calyciflorus. To do this, it is necessary to understand the species’ population ecology. Four surveys of zooplankton were conducted in May, August, and December 2018 and February 2019 in the Pearl River Delta, China, to examine the population characteristics of B. calyciflorus. The temporal and spatial distribution of abundance, biomass, dominance, and occurrence frequency were compared with those from 2012 to investigate the relationship between changes in the population of B. calyciflorus and environmental factors. The average abundance, dominance, and occurrence of B. calyciflorus in this survey were significantly higher than those of 2012 in all seasons. Principal component analysis showed that environmental factors such as the temperature, transparency, total nitrogen, and total phosphorus of water had a major impact on the abundance of B. calyciflorus. There was a significant positive correlation with transparency, total nitrogen, and total phosphorus of water, and a very significant positive correlation with water temperature. Overall, these results demonstrated that the distribution characteristics of B. calyciflorus can reflect pollution in water bodies and can be used to evaluate water quality. These research results provide a reference for evaluating China’s river health and can help to manage water quality in the Pearl River Delta.


2021 ◽  
Vol 13 (10) ◽  
pp. 5445
Author(s):  
Muyun Sun ◽  
Jigan Wang ◽  
Ting Wen

Creativity is the key to obtaining and maintaining competitiveness of modern organizations, and it has attracted much attention from academic circles and management practices. Shared leadership is believed to effectively influence team output. However, research on the impact of individual creativity is still in its infancy. This study adopts the qualitative comparative analysis method, taking 1584 individuals as the research objects, underpinned by a questionnaire-based survey. It investigates the influence of the team’s shared leadership network elements and organizational environmental factors on the individual creativity. We have found that there are six combination of conditions of shared leadership and organizational environmental factors constituting sufficient combination of conditions to increase or decrease individual creativity. Moreover, we have noticed that the low network density of shared leadership is a sufficient and necessary condition of reducing individual creativity. Our results also provide management suggestions for practical activities during the team management.


2013 ◽  
Vol 830 ◽  
pp. 372-375 ◽  
Author(s):  
Yang Wang ◽  
Yu Min Shi ◽  
Jun Zhao

Liaohe River is one of seven big river in China, its environmental pollution control is an important task all the time. In this paper, Liaohe River basin ecological footprint was introduced, water quality and ecological restoration measures were analyzed in the period of the 9th Five-Year, the 10th Five-Year and the 11th Five-Year, the development on ecological restoration in the 12th Five-Year was put forward.


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