Multi-proxy evidence for compositional change of organic matter in the largest tropical (peninsular) river basin of India

Pradhan, U.K.; Wu, Ying; Shirodkar, P.V.; Zhang, Jing; Zhang, Guosen

doi:10.1016/j.jhydrol.2014.08.018

Cited by 23 publications

(35 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The grain size of sediment samples was measured after removing the OM by using a Coulter laser granular meter (LS‐100Q) as previously described by Pradhan, Wu, Shirodkar, Zhang, and Zhang (). Briefly, 0.5 g of dry unground sediment was treated with 10% H 2 O 2 to remove OM.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Spatial and temporal variations in source, diagenesis, and fate of organic matter in sediments of the Netravati River, India

Fernandes

Shirodkar

et al. 2019

Hydrological Processes

Self Cite

View full text Add to dashboard Cite

Organic matter (OM) such as organic nitrogen plays a substantial role in the global biogeochemical cycling of bio‐reactive components—amino acids (AA) in aquatic environments. Spatial and temporal variations in source, diagenesis, and fate of organic nitrogen such as AA in sediments of small tropical rivers and the role of oxbow/meandering loops under changing climatic conditions are poorly investigated. This study assessed the spatial and seasonal variations in OM composition, source, and diagenesis of a tropical small mountainous river—Netravati River, India, for 1 year. Water samples were determined for suspended particulate matter, and surface sediments were examined for bulk parameters, surface area (SA), and the L‐ and D‐enantiomers of AA. The L‐ and D‐enantiomers of AA displayed subtle seasonal variations in composition and depicted varying degrees of diagenesis. The concentration of D‐enantiomer of AA was high and showed substantial contributions from bacteria, terrestrial source, and in situ production. The D‐arginine was the most abundant D‐enantiomer of AA in the study area, possibly due to extracellular secretion by bacterial species and adsorption onto sediments, and thus, it was protected from degradation. Degradation index was more negative at the oxbow and meandering loop stations during the dry season suggesting that local geomorphologic settings steer the diagenesis of OM within the river. A negative relationship between gamma‐aminobutyric acid and organic carbon:surface area (OC:SA) ratio and a positive correlation between tyrosine and OC:SA ratio suggested accelerated loss of OM. Furthermore, the concentrations of most bulk parameters were higher in the lower reaches during monsoon and premonsoon seasons. Taken together, changes in seasons have an operational control in distinguishing the composition, source, and diagenesis of spatial OM distribution. Moreover, oxbows and river meandering loops influence the diagenetic processes in small tropical river systems.

show abstract

Section: Methodsmentioning

confidence: 99%

“…Briefly, 0.5 g of dry unground sediment was treated with 10% H 2 O 2 to remove OM. Sediment grain sizes were expressed as a proportion of clay (<4 μm), silt (4–63 μm), and sand (>63 μm) with a measurement error of ≤1% in the entire dataset (Pradhan et al, ).…”

Section: Methodsmentioning

confidence: 99%

Spatial and temporal variations in source, diagenesis, and fate of organic matter in sediments of the Netravati River, India

Fernandes

Shirodkar

et al. 2019

Hydrological Processes

Self Cite

View full text Add to dashboard Cite

show abstract

“…It demands further research to establish whether the monsoonal eutrophication in impounded reaches of 315 Indian rivers usually leads to an enhanced heterotrophy, rather than a boost in autotrophy, increasing CO2 outgassing from the impounded reaches and downstream estuaries (Prasad et al, 2013). Pradhan et al (2014) reported that during dry years lower rainfalls, combined with impoundment effects, increased the fraction of labile OM derived from the riverine and estuarine phytoplankton. Ramesh et al (2015) observed that damming of rivers and construction of reservoirs significantly increased the retention of particulate OM in the Godavari and Krishna rivers.…”

Section: Effects Of River Impoundmentsmentioning

confidence: 99%

Reviews and syntheses: Anthropogenic perturbations to carbon fluxes in Asian river systems: Concepts, emerging trends, and research challenges

Park¹,

Nayna²,

Begum³

et al. 2018

Preprint

View full text Add to dashboard Cite

Abstract. Human activities are drastically altering water and material flows in river systems across Asia. These anthropogenic perturbations have rarely been linked to the carbon (C) fluxes of Asian rivers that may account for up to 40-20 50% of the global fluxes. The primary object of this review was to provide a conceptual framework for assessing human impacts on Asian river C fluxes, along with a latest update on anthropogenic alterations of riverine C fluxes, focusing on the impacts of water pollution and river impoundments on CO2 outgassing from the rivers draining South, Southeast, and East Asian regions that account for the largest fraction of river discharge and C exports from Asia and Oceania. Recent booms in dam construction across Asia have created a host of environmental problems; yet only a small number of studies have 25 explicitly investigated altered rates of greenhouse gas (GHG) emissions and organic C transport. There have been contrasting reports on impoundment effects: decreases in GHG emissions in the reservoirs exhibiting enhanced primary production vs. increased emissions from the flooded vegetation and soils in the early years following dam construction or from the impounded river reaches and downstream estuaries during the monsoon period. These contrasting results suggest that the rates of metabolic processes in the impounded and downstream reaches can greatly vary longitudinally over time, as 30 a combined result of diel shifts in the balance between autotrophy and heterotrophy, seasonal fluctuations between the dry and monsoon periods, and a long-term change from a leaky post-construction phase to a gradual C sink. Rapid pace of urbanization across southern and eastern Asian regions has dramatically increased municipal water withdrawal, generating annually 120.2 km 3 of wastewater in 24 countries, which comprises 38.6% of the global municipal wastewater production disproportionately affect the receiving river water, particularly downstream of rapidly expanding metropolitan areas, including eutrophication, increases in the amount and lability of organic C, and pulse emissions of CO2 and other greenhouse gases (GHGs). As reviewed for three representative rivers (the Ganges, Mekong, and Yellow River), the lower reaches of these rivers and their polluted tributaries tend to exhibit higher levels of organic C and the partial pressure of CO2 (pCO2) than the eutrophic reservoirs and less impacted upstream reaches. More field measurements of pCO2, together with accurate 40 flux calculations based on river-specific model parameters, are urgently required to provide more accurate estimates of GHG emissions from the Asian rivers that are now underrepresented in the global C budgets. Researchers working on individual river systems need to be linked to collaborative research networks to facilitate global synthesis of local field data. These synthesis efforts, combined with conceptual and mathematical models, will contribute to a better understanding of how anthropogenic perturbations in rapidly urb...

show abstract

“…The Godavari is the largest river of India not draining the Himalayas with a catchment area of 310 × 10 3 km 2 (Balakrishna and Probst, 2005) and a length (of the main river) of 1465 km (Ramasubramanian et al, 2006). The principal trib-utaries of the river are the Pranhita, Wainganga, and Wardha forming a subcatchment (called Pranhita) in the north and the Indravati and Sabari draining the Eastern Ghats (called Indravati).…”

Section: Godavarimentioning

confidence: 99%

Long-chain diols in rivers: distribution and potential biological sources

et al. 2018

View full text Add to dashboard Cite

Abstract. Long-chain diols (LCDs) occur widespread in marine environments and also in lakes and rivers. Transport of LCDs from rivers may impact the distribution of LCDs in coastal environments, however relatively little is known about the distribution and biological sources of LCDs in river systems. In this study, we investigated the distribution of LCDs in suspended particulate matter (SPM) of three river systems (Godavari, Danube, and Rhine) in relation with precipitation, temperature, and source catchments. The dominant long-chain diol is the C32 1,15-diol followed by the C30 1,15-diol in all studied river systems. In regions influenced by marine waters, such as delta systems, the fractional abundance of the C30 1,15-diol is substantially higher than in the river itself, suggesting different LCD producers in marine and freshwater environments. A change in the LCD distribution along the downstream transects of the rivers studied was not observed. However, an effect of river flow is observed; i.e., the concentration of the C32 1,15-diol is higher in stagnant waters such as reservoirs and during seasons with river low stands. A seasonal change in the LCD distribution was observed in the Rhine, likely due to a change in the producers. Eukaryotic diversity analysis by 18S rRNA gene sequencing of SPM from the Rhine showed extremely low abundances of sequences (i.e., < 0.32 % of total reads) related to known algal LCD producers. Furthermore, incubation of the river water with 13C-labeled bicarbonate did not result in 13C incorporation into LCDs. This indicates that the LCDs present are mainly of fossil origin in the fast-flowing part of the Rhine. Overall, our results suggest that the LCD producers in rivers predominantly reside in lakes or side ponds that are part of the river system.

show abstract

Multi-proxy evidence for compositional change of organic matter in the largest tropical (peninsular) river basin of India

Cited by 23 publications

References 48 publications

Spatial and temporal variations in source, diagenesis, and fate of organic matter in sediments of the Netravati River, India

Spatial and temporal variations in source, diagenesis, and fate of organic matter in sediments of the Netravati River, India

Reviews and syntheses: Anthropogenic perturbations to carbon fluxes in Asian river systems: Concepts, emerging trends, and research challenges

Long-chain diols in rivers: distribution and potential biological sources

Contact Info

Product

Resources

About