TIME SERIES ANALYSIS OF HYDROLOGIC DATA

Abstract

The purpose of this study is to investigate the structure of the hydrologic time series of monthly river flows and spring level fluctuations of open wells. The records of monthly runoff from Ganga basin and half yearly water surface levels for seven open wells in Ganga Yarruna' doab in district Nuzaffar Nagar, thus constituting two different time series, have been analyzed. The trend and periodic component i.e. deterministic part have been detected and isolated from the stochastic component of the time series. The trends obtained by the hydrologic data may be useful in planning and control of water resources, and prediction of future Irrigation water supply systems. In the analysis of records, both the correlation methods and power spectrum methods have been used. The correlograms have been developed to know the fundamental cycles present in the hydrologic data. For the analysis of its other sub-harmonies, the effect of removing periods from the time series, on the correlogram, have also been studied. The squared amplitudes $ of the periodic component at various frequencies have been computed to draw the periodograms. The spectral methods have also been used to detect the various important cycles present in the data, with their relative signif cance