Oscillations of the hydrometeorological characteristics in the re-gion of Lake Chapala for intervals of days to decades

Abstract

A spectral analysis is presented for the principal hydrometeorological characteristics in the region of Lake Chapala: air temperature, precipitation, evaporation, atmospheric pressure, wind, level of the lake and volume of flow of the rivers. The time series were grouped with equal discretization and duration. Using linear and nonlinear methods of spectral analysis (maximum entropy and maximum likelihood) the main periods were identified in the range of days to decades, obtaining estimates of the mean square amplitudes. The physical causes of the oscillations are discussed as are the internal relationships between the fluctua- tions of the different hydrometeorological parameters. The causes of the long-term variations in the level of the lake as well as the periodic outbreaks of water lilies are discussed.