scholarly journals Studies on the bottom faunal diversity of Ganga River system in relation to water quality adjacent to Serampore area, West Bengal

2009 ◽  
Vol 22 (1) ◽  
Author(s):  
ASIM KUMAR NATH
2021 ◽  
Vol 24 (2) ◽  
pp. 43-51
Author(s):  
Atul K. Singh ◽  
Sharad C. Srivastava ◽  
Pushpendra Verma

Abstract In order to assess the distribution pattern and understand the prevailing factors for predicting further expansion of an exotic fish Oreochromis niloticus, this study was undertaken in the Ganga river flowing through the state of Uttar Pradesh using MaxEnt model. The authors report the distribution pattern of O. niloticus and prevailing causative factors mounting the expansion of O. niloticus in the Ganges based on MaxEnt modeling technique. The presence only occurrence data-set for this invasive species was prepared from the field data and also from data collated from the authenticated publications of different fisheries researchers. The data-set was analyzed with environmental and topographical variables typically incorporating seasonal and temporal variability using MaxEnt, a maximum entropy algorithm which showed that the area under curve was much closer to 1 ( 0.999). The model predicted elevation as the most influential predictor variable with permutation importance of 69.2% followed by slope_steepness (10.1%), Tmax_1 (7.3%) and Srad_5 (6.8%). The findings from the results suggest that invasive O. niloticus tend to spread in rivers where elevation is lower as well as slope_steepness of the river is higher and thus indicated that invasion might be higher in the downstream of the river. The model suggests that topography and its derived variable are the most significant predictors for distribution of invasive O. niloticus. The results of this study also confirm that the water qualities of the Ganga river are suitable for O. niloticus and if the model is supplemented with water quality variables data, the influential predictor variable in water quality can be well investigated with permutation importance.


2020 ◽  
Vol 13 (19) ◽  
Author(s):  
Gagan Matta ◽  
Avinash Kumar ◽  
Anjali Nayak ◽  
Pawan Kumar ◽  
Amit Kumar ◽  
...  

Author(s):  
Hae-Jin Lee ◽  
Hae-Kyung Park ◽  
Se-Uk Cheon

Flow regulation is one of the most common anthropogenic factors affecting rivers worldwide. In Korea, 16 weirs were constructed along four major rivers from 2009 to 2012. This study aimed to elucidate initial changes in physical, chemical, and biological variables after the construction of consecutive weirs on the Nakdong River, a major large river system. Water quality variables and phytoplankton cell densities were investigated at eight representative sites and compared with the data recorded before the weir construction. There were spatial and temporal changes in the hydraulic retention time (HRT), total phosphorus (TP), and chlorophyll a concentrations among the eight weir sections. HRT increased after the weir construction, while TP and chlorophyll a tended to decrease from the middle to lower section of the Nakdong River. Furthermore, differences were observed in the phytoplankton community composition between 2006–2007 and 2013. There was a marginal decrease in the duration of centric diatom (Stephanodiscus hantzschii) blooms after weir construction. However, Microcystis aeruginosa proliferated more extensively during summer and autumn than it did before the weir construction. Our results suggest that changes in hydrological factors, in response to consecutive weir construction, may contribute to greater physical, chemical, and ecological variability.


2005 ◽  
Vol 75 (5) ◽  
pp. 1012-1019 ◽  
Author(s):  
S. Dutta ◽  
R. K. Kole ◽  
S. Ghosh ◽  
D. Nath ◽  
K. K. Vass

2018 ◽  
pp. 273-285
Author(s):  
T. M. Tompkins ◽  
W. W. Whipps ◽  
L. J. Manor ◽  
M. J. Wiley ◽  
C. W. Radcliffe ◽  
...  

2016 ◽  
Vol 19 (2) ◽  
pp. 107-117
Author(s):  
Trang Thi Thuy Nguyen ◽  
Khoi Nguyen Dao

The objective of this study was to simulate the hydrologic characteristic and water quality of 3S rivers system (Sekong, Sesan and Srepok) using SWAT model (Soil and Water Analysis Tool). Agriculture and forest are the main land use types in this basin accounting for more than 80 % of the total area. Therfore, nitrogen and phosphorus were selected to be parameters for water quality assessment. SWAT-CUP model was applied to calibrate the model for stream flow and water quality based on SUFI-2 (Sequential Uncertainty Fitting version 2) method. The model performance has been assessed by three statistical indices, including coefficient corellation (R2), Nash-Sutcliffe efficient coefficience (NSE) and percentage Bias (PBIAS). The results showed that SWAT model was well calibrated for simulating the streamflow and water quality with the values of R2 greater than 0.5 except for the Attapeu and Kontum stations, and of PBIAS less than 10 % and 35 % for streamflow and water quality, respectively. The well-calibrated SWAT model can be applied in predicting the hydrology and water quality for other application. Furthermore, it is a tool supporting the policy makers to offer a suitable decisions regarding the sustainable river basin management.


2016 ◽  
Vol 15 (4) ◽  
pp. 11-22
Author(s):  
H M Ashashree ◽  
H A Sayeswara ◽  
K L Naik ◽  
N Kumara Swamy ◽  
Nafeesa Begum

Fresh water wetlands are fragile ecosystems, which are fast deterioring and shrinking due to manmade activities. The fish composition of Huchharayanakere of Shikaripura was studied for a period of twelve months from January to December 2015. The icthyo-faunal diversity of this pond confirmed the occurrence of 13 species of fishes belonging to 5 families. The family Cyprinidae represented by 9 species. Families Anabantidae, Bagridae, Clupeidae and Notopteridae were represented by only a single species. Simultaneously the physico-chemical condition of the water body revealed that water quality is suitable for fish culture. The study of fish fauna of an aquatic body is useful for planning of fisheries development. The pond needs proper management and utilization of this fish wealth and sustainable steps to monitor and conserve the fish health. The present study revealed that Huchharayanakere of Shikaripura harbors wide varieties of fish with economic importance in local and global trade. The study will provide future strategies for development and fish conservation.


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