Modeling the spatial and temporal variability in surface water CO2 and CH4 concentrations in a newly created complex of boreal hydroelectric reservoirs

Variation of Air-Sea CO2 Fluxes in Bintan Island Coastal Water. Eastern part of Bintan coastal water plays a major role as CO2 sink. However, flux and partial pressure of CO2 (pCO2) dynamically follows spatio-temporal variability. Spatio-temporal variability of CO2 flux may shows the whole condition of Bintan Island coastal water, especially in correlation with the primary production. Systematic study on variability of CO2 flux from or to the watern column is essential to understand the whole conditions of Bintan Island coastal water. This study aims to understand the spatio-temporal variation of CO2 fluxes in Bintan Island coastal water, and the factors influencing it. This study was conducted in the eastern part of Bintan coastal water in April and August 2014. In addition, this study was also conducted in the southern and northern parts in April 2016. CO2 fluxes dynamics were calculated from pCO2 (surface water and atmosphere), temperature, salinity, and wind speed. The result showed that almost all parts of the Bintan coastal water were carbon sources during first transition season. The largest CO2 emission was observed in the northern part (4.02 ± 1.92 mmol/m2/d) followed by the southern part (2.28 ± 0.80 mmol/m2/d) and then the eastern part (0.46 ± 0.28 mmol/m2/d). The eastern part temporally turned into CO2 sink in the southwest monsoon season (-0.27 ± 0.10 mmol/m2/d). Temperature was the main factor causing spatial and temporal variability of air-sea CO2 fluxes in the Bintan coastal water. Spatially, the presence of seagrass and coral reef ecosystems causes the partial pressure of surface water CO2 in the eastern part of waters of Bintan is much lower compared to the waters of north and south Bintan, thus emitting less CO2 to the atmosphere

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Spatial and temporal variability of surface water pollution in the Mekong Delta, Vietnam

The Science of The Total Environment ◽

10.1016/j.scitotenv.2014.03.049 ◽

2014 ◽

Vol 485-486 ◽

pp. 653-665 ◽

Cited By ~ 57

Author(s):

Gert-Jan Wilbers ◽

Mathias Becker ◽

La Thi Nga ◽

Zita Sebesvari ◽

Fabrice G. Renaud

Keyword(s):

Water Pollution ◽

Surface Water ◽

Temporal Variability ◽

Mekong Delta ◽

Spatial And Temporal Variability ◽

Surface Water Pollution

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Spatial and temporal variability of surface water repellency in sandy loam soils of NW Spain under Pinus pinaster and Eucalyptus globulus plantations

Hydrological Processes ◽

10.1002/hyp.8091 ◽

2011 ◽

Vol 25 (23) ◽

pp. 3649-3658 ◽

Cited By ~ 21

Author(s):

M. Rodríguez-Alleres ◽

E. Benito

Keyword(s):

Surface Water ◽

Temporal Variability ◽

Eucalyptus Globulus ◽

Pinus Pinaster ◽

Sandy Loam ◽

Water Repellency ◽

Spatial And Temporal Variability ◽

Nw Spain

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Implications for water cycle dynamics in the Upper Jhelum River Basin of North-Western Himalayas based on hydrogen and oxygen isotope signatures of precipitation, surface water, and groundwater

10.5194/egusphere-egu21-1077 ◽

2021 ◽

Author(s):

Tanveer Dar ◽

Nachiketa Rai ◽

Sudhir Kumar

Keyword(s):

Surface Water ◽

Stable Isotope ◽

Isotopic Composition ◽

Lake Water ◽

Temporal Variability ◽

Himalayan Region ◽

Spatial And Temporal Variability ◽

Jhelum River ◽

Jhelum River Basin ◽

North Western

We have used stable isotopes of oxygen and hydrogen (&#948;18O and &#948;D) which are important tracers for understanding various hydrological processes, to assess the spatial and temporal variability due to dual moisture sources in the Upper Jhelum River Basin (UJRB) of the north-western Himalayan region. The HYSPLIT back trajectory analysis shows large variability in spatial moisture transport pathways over the region during Southwest monsoon (SWM) and is mainly restricted to the Mediterranean Sea during Western disturbances (WDs). The isotopic composition of precipitation is significantly controlled by temperature and Relative Humidity during precipitation events from WDs; however, this control is found to be weak during the SWM.Stable isotope signatures of precipitation are found to show a well-defined altitudinal effect (&#948;18O=0.19&#8240;/100m) and a negative correlation with ambient temperature (R&#178; = 0.65, p<0.01 for WDs & R&#178;=0.48, p>0.1 for SWM). Mixing various tributary waters with different isotopic compositions leads to variability in the Jhelum River&#8217;s (JR) isotopic composition along its course. The observed spatial variability of &#948;18O and d-excess results from the exchange processes between groundwater and surface water. The higher depletion of precipitation during WDs leads to depletion of surface and groundwater and produces enrichment due to the evaporative loss of heavier isotopes due to drier weather conditions during SWM. Evaporation signals are more prominent in shallow groundwater (SGW) and lake water, indicating SGW being discharged in the proximity of lake water bodies. The isotopic values in the upper reaches are observed to be depleted, potentially due to inputs from melting glaciers and snow. In the middle, it reaches slightly enriched, likely due to shifts in groundwater and rainfall inputs. In the downstream, due to increased residence time and flat topography, the isotopic composition is relatively enriched, potentially related to the evaporative losses of heavier isotopes. The d-excess values in UJRB are found to vary between 11&#8240; to 20&#8240; with an average value of ~17&#8240;, which is relatively higher than the long-term average observed for the Indian summer monsoon (~8&#8240;), and Upper Indus in the Ladakh region (11.7&#8240;) but almost similar to observed for Lower Indus (18&#8240;).The contribution of moisture from each source (WDs and SWM) are estimated using a two-component mixing model. The moisture source contribution over UJRB via WDs is 75%(&#177;20) from the Mediterranean Sea and 20%(&#177;10) from SWM. WDs contribution over UJRB is higher than in the Trans-Himalayan region in the Ladakh (Indian sector in the east) but smaller in Lower Indus Basin (Pakistan sector in the west). Hence, the influence of moisture of WDs decreases from west to east along the Himalayan region. This work based on stable isotope geochemistry of oxygen and hydrogen highlights the effects of meteorological and physiographic controls on the moisture dynamics and contributes to explain the spatial and temporal variability of hydrologic processes in the region.

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Chemical pollution from urban and industrial sewages in Augusta Bay (Sicily)

Water Science & Technology ◽

10.2166/wst.1995.0688 ◽

1995 ◽

Vol 32 (9-10) ◽

pp. 221-229 ◽

Cited By ~ 3

Author(s):

G. Magazzù ◽

G. Romeo ◽

F. Azzaro ◽

F. Decembrini ◽

F. Oliva ◽

...

Keyword(s):

Surface Water ◽

Temporal Variability ◽

Petroleum Hydrocarbons ◽

Cooling Water ◽

Fish Mortality ◽

Chemical Pollution ◽

Spatial And Temporal Variability ◽

High State ◽

High Level ◽

Very High

The Augusta Bay is a complex area where heavy industrialization and dense urbanization have promoted a very high state of degradation. This basin has already been studied for several years because of various eutrophication phenomena which induced a massive fish mortality. In order to deepen our knowledge on the state of chemical pollution due to Dissolved/Dispersed Petroleum Hydrocarbons (DDPH), detergents and N- and P-salts as well as on the eutrophication of the bay, three campaigns have been carried out. The results (from 0.0 to 96.6 μg/l in chrysene equivalents) have indicated that the distribution of DDPH is characterized by an extreme spatial and temporal variability linked to occasional localized spills and to the wind's action which influences the surface water circulation in the bay. The concentration of non ionic (BiAS) and ionic (ABS) detergents averages respectively 63 and 55 μg/l with a predominance of BiAS in the waters affected by the urban discharges, while high ABS values have been also measured in correspondence of a cooling water effluent. Finally, the PO4 (max 0.3 μ/l) and NO2 + NO3 (max 4 μl) levels were relatively low and constant in comparison with previous results, while NH4 remains at a high level (max 14.6 μ/l) with supplies located in the urban discharge as well as in the industrial ones, indicating that both types of effluents are equally responsible for eutrophication and the distrophic crisis observed in the bay.

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