scholarly journals Environmental Variables of the Seti Gandaki River Basin Pokhara, Nepal

2018 ◽  
Vol 22 (2) ◽  
pp. 129-139 ◽  
Author(s):  
Kishor Kumar Pokharel ◽  
Khadga Bahadur Basnet ◽  
Trilok Chandra Majupuria ◽  
Chitra Bahadur Baniya
Keyword(s):  
Water Temperature ◽  
River Basin ◽  
Environmental Variables ◽  
Temporal Variations ◽  
Total Alkalinity ◽  
Urban Site ◽  
Water Conductivity ◽  
Free Carbon Dioxide ◽  
Spatio Temporal ◽  
Carbon Dioxide Co2

Present paper focuses on the spatio-temporal variations and correlations among the environmental variables of the Seti Gandaki River basin, Pokhara, Nepal. A total of five sites, three along the river and two in tributaries were selected for this study. Water sampling was done fortnightly for environmental variables following standard methods during July 2011 to June 2012. Mean and standard deviation of the environmental variables revealed that the depth (0.9 ± 0.3), pH (8 ± 0.4), total phosphates (PO4) (0.10 ± 0.03) and nitrates (NO3) (0.13 ± 0.04) were normally variable among the sites. But the discharge (40.00 ± 37.00), width (32.30 ± 13.00), turbidity (81.40 ± 51.00), transparency (29.10 ± 15.00), conductivity (166.00 ± 80.00), water temperature (18.00 ±4.00), dissolved oxygen (DO) (8.00 ± 2.00), free carbon dioxide (CO2) (7.00 ± 2.00) and total alkalinity (98.00 ± 22.00) varied among sites equally. Correlation coefficient between the sites and environmental variables revealed that sites were found significantly correlated with water conductivity (r2 = 0.6), DO (r2 = -0.52), and free CO2 (r2 = 0.6); depth of water with width (r2 = 0.94), discharge (r2 = 0.96), turbidity (r2 = 0.71), transparency (r2 = -0.62), water temperature (r2 = 0.60), pH (r2 = -0.52) and DO (r2 = -0.48); water temperature with pH (r2 = -0.54), DO (r2 = -0.79), free CO2 (r2 = 0.69), total alkalinity (r2 = -0.58), total PO4 (r2 = 0.54) and NO3 (r2 = 0.62), etc. The enhancement of turbidity, conductivity, free CO2, phosphates and nitrates, while, suppression of transparency, pH and DO at the urban site indicated the urban influence. Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018, page: 129-139

scholarly journals Spatio-temporal variations of water quality and phytoplankton diversity of the different rivers flowing within Sundarban mangrove wetland ecosystem of Bangladesh

2019 ◽  
Vol 5 (1) ◽  
pp. 61-76
Author(s):  
A Ahmed ◽  
N Akter ◽  
S Hasan ◽  
M Ataullah
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Temporal Variations ◽  
Mangrove Forests ◽  
Water Conductivity ◽  
Phytoplankton Diversity ◽  
A Value ◽  
Positive Loading ◽  
Sundarban Mangrove ◽  
Spatio Temporal

The water of different rivers passing in the Sundarban Mangrove Forests (SMF) of Bangladesh was analyzed to know the spatio-temporal variations in the water quality and phytoplankton diversity of the river. The pH of the waters of all the rivers examined showed a narrow range of variation (6.60-7.8 in 2015 and 6.3 to 7.5 in 2016) indicating the buffering capacity of different rivers. The values of pH showed a slightly decreasing tendency indicating the acidification of river waters which might be due to increase of global CO2 concentration in the atmosphere. The temperature of water, conductivity, salinity, DO (ppm), DO (% sat), K, Na, was found to vary from 27.6 to 30.8° C, 8.00 to 32.30 mS/cm, 5.50 to 23.00 ‰, 3.5 to 6.35 ppm, 46.60 to 82.00 %, 125.00 to 630.00 mg/l, 600 to 4300 ppm, respectively in April 2015; and ranged from 28.8 to 31.0° C, 9.48 to 31.60 mS/cm 5.00 to 24.00 ‰, 0.11 to 5.33 ppm, 1.2 to 95.2 % saturation, 110 to 670 ppm, 4683.5 to 13465.10 ppm, respectively in March 2016. The values of Ca, Mg and Fe were 210 to 500 ppm, 320.0 mg/l to 892.0 mg/l and 0.25 to 0.050 mg/l, respectively in 2015. The amount of DO was very low during 2016 especially in the locations 1, 2, 3 which might be due to cloudy condition during sampling time. Principal component analyses (PCA) of different variables of the year 2015 showed that PC-1 had positive loading of water temperature, air temperature, humidity, pH, conductivity, Salinity, Na, K, Fe, Mg, Zn whereas PC-1 of different variables during 2016 showed positive loading of only water temperature and pH. Maximum number of phytoplankton taxa was recorded from Sela river (Tambulbunia) where 34 taxa (with the unknown ones) were recorded followed by Passur river (near Mongla Ferry Ghat). Coscinodiscus is found to be the dominant genus. Maximum Shannon-Weaver index of diversity was found in Homra Khal (value was 6.825) and minimum was found in Sela river (where the oil tanker sank and value was 0.0). Only one species of phytoplankton was found in this place. Maximum species richness (d) was observed in Passur river at Mongla ferry ghat with a value of 14.81 whereas, maximum evenness (e) was found in location 16 (Homra khal with a value of 5.437). J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(1): 61-76

scholarly journals Diel dynamics of heleoplankton in relation to some physico-chemical attributes of water in an aquaculture tank in Guwahati, Assam

2012 ◽  
Vol 4 (1) ◽  
pp. 16-22
Author(s):  
Janardan Pathak ◽  
M. M. Goswami
Keyword(s):  
Water Temperature ◽  
T Test ◽  
Total Alkalinity ◽  
Diurnal Fluctuation ◽  
Total Hardness ◽  
Numerical Density ◽  
Physico Chemical ◽  
Free Carbon Dioxide ◽  
Chemical Attributes ◽  
Positive Correlations

Diurnal fluctuation of the phytoplankton and zooplankton population (numerical densities) and the physicochemical attributes of water are studied in an aquaculture pond at Guwahati, Assam. In the 24 hour diel cycle, the phytoplankton and zooplankton show significant (t-test, p < 0.01) variation in their numerical density at an interval of 4 hours. The studied physico-chemical parameters of water included Temperature, Total Alkalinity (TA), Total hardness (TH), Dissolved Oxygen (DO), Free Carbon dioxide (FCO2) and pH are analyzed concurrently, which reveals a significant fluctuation (t-test, p< .01) in the day and night hours. Multivariate correlation analysis portrays significant and positive correlations among the total population density of phytoplankton with respect to water temperature (r = 0.845, p<0.05) and pH (r = 0.881, p< 0.01) while it maintains significant negative correlations with TA (r = -0.837, p<0.05), TH (r = -0.768, p< 0.05) and FCO2 (r = -0.830, p<0.05). However, total numerical density of zooplankton reveals positive and significant correlations with TA (r = 0.842, p< 0.05) and FCO2 (r= 0.758, p< 0.05) while it shows significant negative correlations with water temperature (r = -0.906, p< 0.01) and pH (r =- 0.912, p< 0.01).

scholarly journals Study on Fish Ecology of the Seti Gandaki River Pokhara: II. Spatio-Temporal Variations in Fish Communities

2012 ◽  
Vol 12 ◽  
pp. 350-357 ◽  
Author(s):  
KK Pokharel
Keyword(s):  
Winter Season ◽  
Temporal Variations ◽  
Urban Site ◽  
Total Density ◽  
Brachydanio Rerio ◽  
Upstream Site ◽  
Longitudinal Pattern ◽  
Total Fish ◽  
Spatio Temporal ◽  
Pokhara Valley

Present paper deals with the spatio-temporal variations in distribution and abundance of fishes along the 30 km stretch of the Seti Gandaki river and its two major tributaries, Mardi Khola and Vijaypur Khola, in Pokhara Valley, Western Nepal. A total of 30 species of fishes belonging to 5 orders, 9 families and 22 genera were recorded from five sites on the river and its tributaries. Cyprinoids were predominant among fishes (17 spp.), siluroids (5 spp.), balitorids and cobitids (4 spp.), channioids (2 spp.), belonoids (one sp.) and mastacembeloids (one sp.). Among cyprinoids, mostly cyprinines were dominant groups (7 spp.) followed by rasborines (7 spp.), garrines (2 spp.) and schizothoracines (one sp.). There was increasing trend of species richness at upstream site (17 spp.). to downstream site (20 spp.) showing a longitudinal pattern. The total fish abundance and family-wise abundance at all the sites observed major peak during the spring and fall during the winter season in both the years of study. The average total density of fishes during the spring peak was highest (51.07/ha) at the upper tributary site and lowest (24.69/ha) at the urban site. According to the distribution pattern and abundance, the population status of the gamefish, mahseer [Tor tor (Ham)] has been endangered (E); that of game fishes [Tor putitora (Ham.) and Chagunius chagunio (Ham.)] and Zebra-fish [Brachydanio rerio (Ham.)] to are vulnerable (V); that of loach [Lepidocephalus guntea (Ham.)], cat-fishes [Myersglanis blythii (Day) and Amblyceps mangois (Ham.)] are rare (R).DOI: http://dx.doi.org/10.3126/njst.v12i0.6523 Nepal Journal of Science and Technology 12 (2011) 350-357

The spatio-temporal variations of vegetation cover in the Yellow River Basin from 2000 to 2010

2013 ◽  
Vol 33 (24) ◽  
Author(s):  
袁丽华 YUAN Lihua ◽  
蒋卫国 JIANG Weiguo ◽  
申文明 SHEN Wenming ◽  
刘颖慧 LIU Yinghui ◽  
王文杰 WANG Wenjie ◽  
...  
Keyword(s):  
River Basin ◽  
Vegetation Cover ◽  
Yellow River ◽  
Yellow River Basin ◽  
Temporal Variations ◽  
The Yellow River ◽  
Spatio Temporal ◽  
The Yellow River Basin

scholarly journals Spatio-temporal variations of water quality in Nova Ponte Reservoir, Araguari River Basin, Brazil

2017 ◽  
Vol 17 (6) ◽  
pp. 1507-1514 ◽  
Author(s):  
Cristiano Christofaro ◽  
Mônica M. Diniz Leão ◽  
Sílvia M. A. C. Oliveira ◽  
Déborah T. Viana ◽  
Camila C. Amorim ◽  
...  
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Temporal Variations ◽  
Spatio Temporal

Investigating of River-Aquifer Interactions using Sub-Surface Hydrological Model and Remote Sensing Inputs in an agriculturally Dominated Kosi River Basin, India.

2021 ◽  
Author(s):  
Naga Venkata Satish Laveti ◽  
Suresh A. Kartha ◽  
Subashisa Dutta
Keyword(s):  
Remote Sensing ◽  
Groundwater Recharge ◽  
River Basin ◽  
Hydrological Model ◽  
Temporal Variations ◽  
Interaction Process ◽  
Groundwater Levels ◽  
Physically Based ◽  
Spatio Temporal ◽  
Exchange Flux

&lt;p&gt;River-Aquifer Interaction is a natural and complex phenomenon for understanding its physical dynamic processes. These interactions highly vary with time and space and are to be investigated at river reach scale. The present study aims to understand and quantify the spatio-temporal variations of river-aquifer interaction process in Kosi river basin, India. This basin is majorly dominated with agricultural lands and irrigation requirement of the crops are mostly met by groundwater. In order to quantify the river-aquifer exchange flux at reach scale, a physically based sub-surface hydrological model has been carried for the study area. For this purpose, high resolution remotely sensed evapotranspiration data and groundwater recharge (estimated using soil water budget method method) along with other aquifer parameters were utilized for simulating the monthly groundwater levels as well as exchange flux between river and aquifer. The model results showed that simulated groundwater levels were well calibrated and validated with measured groundwater levels. Further, this calibrated groundwater flow model has been used to quantify the river-aquifer exchange flux. Based on the obtained exchange flux values, three different interaction zones were identified from upstream (Kosi barrage) to downstream (confluence point with Ganga river) in the study reach. It is observed that the river mostly loses water to the aquifer (as influent) in Zone I (80km from upstream) and the river mostly gains water from the aquifer (as effluent) in Zone III (40 km above downstream to confluence point). Whereas, the river has a combination of both losing and gaining natures in Zone II (between Zone I and III). From this study, it can be concluded that use of satellite remote sensing inputs (groundwater recharge and evapotranspiration) in the sub-surface hydrological model, facilitated to improve the assessment and understanding river-aquifer interaction process in an alluvial River basin.&lt;/p&gt;

Spatio-temporal variations of benthic macroinvertebrates and the driving environmental variables in a shallow lake

2020 ◽  
Vol 110 ◽  
pp. 105948
Author(s):  
Yufeng Yang ◽  
Yujun Yi ◽  
Yang Zhou ◽  
Xuan Wang ◽  
Shanghong Zhang ◽  
...  
Keyword(s):  
Benthic Macroinvertebrates ◽  
Shallow Lake ◽  
Environmental Variables ◽  
Temporal Variations ◽  
Spatio Temporal

scholarly journals Spatiotemporal variations of <I>f</I>CO<sub>2</sub> in the North Sea

2009 ◽  
Vol 6 (2) ◽  
pp. 1655-1686
Author(s):  
A. M. Omar ◽  
A. Olsen ◽  
T. Johannessen ◽  
M. Hoppema ◽  
H. Thomas ◽  
...  
Keyword(s):  
North Sea ◽  
Surface Waters ◽  
Phytoplankton Bloom ◽  
Temporal Variations ◽  
Co2 Exchange ◽  
Atmospheric Co2 ◽  
Total Alkalinity ◽  
The North ◽  
The North Sea ◽  
Spatio Temporal

Abstract. Data from two Voluntary Observing Ship (VOS) (MS Trans Carrier and MV Nuka Arctica), acquired along one zonal and one meridional transect (2005–2007) augmented with data subsets from ten cruises (1987–2005) were used to investigate the spatio-temporal variations of the CO2 fugacity in seawater (fCO2sw) in the North Sea at seasonal and inter-annual time scales. The observed seasonal fCO2sw variations were related to variations in sea surface temperature (SST), biology plus mixing, and air-sea CO2 exchange. Over the study period, the seasonal amplitude in fCO2sw induced by SST changes was 0.4–0.75 times those resulting from variations in biology plus mixing. Along the meridional transect, fCO2sw normally decreased northwards (−12 μatm per degree latitude), but the gradient disappeared/reversed during spring as a consequence of an enhanced seasonal amplitude of fCO2sw in southern parts of the North Sea. Along the zonal transect, a weak gradient (−0.8 μatm per degree longitude) was observed in the mean annual fCO2sw. Annually and averaged over the study area, surface waters of the North Sea were CO2 undersaturated and thus a sink of atmospheric CO2 throughout the year. However, during summer, surface waters in the region 55.5–54.5° N were CO2 supersaturated and, hence, a source for atmospheric CO2. Comparison of fCO2sw data acquired within two 1°×1° regions in the northern and southern North Sea during different years (1987, 2001, 2002, and 2005–2007) revealed large interannual variations, especially during spring and summer when year-to-year fCO2sw differences (≈160–200 μatm) approached seasonal changes (≈200–250 μatm). The springtime variations resulted from changes in magnitude and timing of the phytoplankton bloom, whereas changes in SST, wind speed, and total alkalinity may have contributed to the summertime interannual fCO2sw differences. The lowest interannual variation (10–50 μatm) was observed during fall and early winter. The comparison with data reported in October 1967 suggests that the fCO2sw growth rate in the central North Sea is similar to that in the atmosphere.

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