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| Titel |
Understanding the relationship between rainfall and river discharge: trends in an Amazonian watershed |
| VerfasserIn |
Rodolfo Nóbrega, Alphonce Guzha, Paula Freire, Celso Santos, Gerhard Gerold |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250072474
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| Zusammenfassung |
| A research challenge in the Amazon rainforest is to understand different environmental patterns in a five million km2 region which with poor and/or unavailable environmental data. Deforestation and degradation in this forest have motivated intense monitoring activities in order to understand its impact and support the formulation of sustainable environmental policies. Time series analysis of hydrologic data is often use as a tool to evaluate watershed responses to climatic and anthropogenic influences. In this study, trend analysis of stream discharge from a 35600 km² watershed (Curuá River), located in southern Amazon was performed using 31 years discharge and rainfall data (19762006). The Curuá River is a tributary of Xingu River, site of the controversial Belo Monte dam. The aim of this work was to investigate the temporal variability of discharge, in relation to associated rainfall variability in order to contribute to a better understanding of the hydrological status of the watershed. The Mann Kendall non parametric tests were performed on daily, seasonal and annual discharge data. Frequency analysis using wavelet transform was also done, and annual and seasonal rainfall data was analyzed and correlated to discharge. Results from this study indicate decreasing trends in discharge (intra- and inter-annual) but while there is no evidence of a decreasing trend in in rainfall. Further interpretation of the data for possible causes of discharge changes is needed at the local study level, and implications of these results discussed in the context of climate change, deforestation and water resource management (including dam’s constructions last decades). Results from this study do not confirm findings from other regional scale trend analyses, and therefore is it important to quantify the spatial extension of these decreasing stream flow trends in the Amazonia. |
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