chaotic nature of river flow time series: upstream to downstream

Study the dynamics of runoff in the watershed and how influence of the morphological characteristics is very important in solving water engineering problems. in this paper, the dynamic behavior of the runoff of the four basins located in the iran, on basin in turkey and two basins located in united states using chaos theory is studied. there is several stream gauge station in all selected basin. for all basin time series of runoff extraction and then chaotic parameters are calculated. the delay time is determined using the mutual information method, the embedding dimension and correlation dimension is estimated using the false nearest neighbor algorithm and d2 algorithm, respectively. analysis of the results showed that the correlation dimension has increased from upstream to downstream which constitutes the increasing complexity and number of required variables for modeling. delay times and embedding dimension do not have relationship with position of the station and values are fairly similar to each other. it is clear that we need more studies to reach a general conclusion on this point.