02204naa a2200277 a 450000100080000000500110000800800410001910000210006024501130008126000090019452014120020365000190161565000190163465000110165365000240166465000220168865000080171065300190171865300240173770000170176170000220177870000200180070000180182070000250183877300630186319630622013-07-30       2013    bl uuuu     u00u1 u    #d1 aOVALLE, A. R. C.  aLong-term trends in hydrochemistry in the Paraíba do Sul River, southeastern Brazil.h[electronic resource]  c2013  aThe Paraíba do Sul watershed is an important hydrological resource for southeastern Brazil, that has undergone extensive land use changes related to industrial, agricultural and urban activities. Over 11 years, between 1997 and 2007, a long-term study was conducted to evaluate hydrochemical variation in the basin outlet through estimations of annual fluxes and identification of their controlling factors. River water was classified as Na-HCO3, with TDS ranging from 32 to 132 mg L-1. Variation between sea- sons was found: cations, total alkalinity, electrical conductivity, dissolved oxygen, nitrate and chlorophyll "a" had increased values the during low discharge period, while concentrations of DOC, ammonium, nitrite, phosphate and SPM had increased values during the high discharge period. Chloride, sulfate, silica and pH showed no clear relationship with discharge. These patterns also were correlated with hydrolog- ical flow paths originating from different sources. Wavelet decomposition was used to characterize pre- cipitation anomalies largely associated both with long-term climate factors (i.e. ENSO) and short-term climate responses from the two discharge periods that were studied. Distinct responses of fluvial hydro- chemistry were observed including ENSO-induced fluctuation to be particularly strong for DOC, with annual flux varying approximately 60% around measured median value.  aEutrophication  aHydrochemistry  aRivers  aBacia hidrográfica  aImpacto ambiental  aRio  aEutroficação  aRio Paraíba do Sul1 aSILVA, C. F.1 aREZENDE, C. E. de1 aGATTS, C. E. N.1 aSUZUKI, M. S.1 aFIGUEIREDO, R. de O.  tJournal of Hydrology, Amsterdamgv. 481, p. 191-203, 2013.