Methods of assessment of spatio-temporal fluctuations(based on the example of the Upper Ob basin)

A variety of methods is used to assess the alterations in the water content across a territory as well as the synchronism and asynchronism of its fluctuations over extended periods. Among them: comparative analysis of graphs showing time series of the annual flow, piecewise linear trends, flow records of sliding periods averaging, integrally differential curves. When all the methods listed above are used together, the accuracy of the results is confirmed. Analyzing fluctuations in annual streamflow of the Upper Ob basin over extended periods with the help of techniques that were listed above one may conclude that there is no rigid periodicity in the annual flow fluctuations. Different nature of the perennial cyclic runoff in remote areas is detected.

river drain, spatial and time fluctuations, ways of analysis