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

IR@NIO: CSIR-National Institute Of Oceanography, Goa

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Creator Pradhan, U.K.
Ying Wu
Shirodkar, P.V.
Zhang, J.
Zhang, G.
 
Date 2014-12-11T06:40:59Z
2014-12-11T06:40:59Z
2014
 
Identifier Journal of Hydrology, vol.519; 2014; 999-1009
http://drs.nio.org/drs/handle/2264/4661
 
Description The distribution and compositional changes of organic matter (OM) within the Godavari river system is increasingly influenced by reduced monsoon rainfall and an increased number of damming. To track these changes stable isotopes of organic carbon and concentrations of lignin phenols were analyzed in total suspended matter (TSM), sediments, agriculture soils and plants from Godavari basin. The results indicated that the upper tributaries drained heavier carbon (δ13Corg = −20.4 ± 2.2‰) than the lower tributaries (δ13Corg = −25.4 ± 1.5‰) owing to the regional vegetation in the upper to lower basins. OM originating from algae near dam impoundments was incorporated into TSM and sediment due to extreme drought condition. The organic carbon (OC) content was higher in TSM and in the sediment of the region after the middle reach dam (Sriram Sagar) than before (2.2 ± 1.6 vs. 1.0 ± 0.1% OC and 2.1 ± 2.3 vs. 0.6 ± 0.2% OC, respectively). The lignin yield (Λ8) was lower in TSM and in the sediment after the dam impoundment than before (0.37 vs. 1.94 mg/100 mg OC and 2.9 ± 1.1 vs. 5.4 ± 2.3 mg/100 mg OC, respectively) due to an increased contribution of lignin free OC from algae and degraded soil. Less rainfall and dam impoundments enhanced the fraction of labile OM from freshwater algae and an estuarine phytoplankton bloom in the study year. Our study is the first to document lignin fluxes from an Indian monsoonal river (Godavari). The flux of lignin phenols of 7.26 × 109 g yr−1 is much lower than those of most world rivers except the rivers from polar arctic.
 
Language en
 
Publisher Elsevier
 
Rights An edited version of this paper was published by Elsevier. Copyright [2014] Elsevier
 
Subject organic carbon
carbon isotopes
lignin phenols
composition
 
Title Multi-proxy evidence for compositional change of organic matter in the largest tropical (peninsular) river basin of India
 
Type Journal Article