A water level relationship between consecutive gauge stations along Solim\~oes/Amazonas main channel: a wavelet approach

摘要

Gauge stations are distributed along the Solim\~oes/Amazonas main channel tomonitor water level changes over time. Those measurements help quantify boththe water movement and its variability from one gauge station to the nextdownstream. The objective of this study is to detect changes in the water levelrelationship between consecutive gauge stations along the Solim\~oes/Amazonasmain channel, since 1980. To carry out the analyses, data spanning from 1980 to2010 from three consecutive gauges (Tefe, Manaus and Obidos) were used tocompute standardized daily anomalies. In particular for infra-annual periods itwas possible to detect changes for the water level variability along theSolim\~oes/Amazonas main channel, by applying the Morlet Wavelet Transformation(WT) and Wavelet Cross Coherence (WCC) methods. It was possible to quantify thewaves amplitude for the WT infra-annual scaled-period and were quite similar tothe three gauge stations denoting that the water level variability are relatedto the same hydrological forcing functions. Changes in the WCC was detected forthe Manaus-Obidos river stretch and this characteristic might be associatedwith land cover changes in the floodplains. The next steps of this research,will be to test this hypotheses by integrating land cover changes into thefloodplain with hydrological modelling simulations throughout the time-series.