ABSTRACT
The effect of El-Nino Southern Oscillation (ENSO) on rainfall characteristics over Karachi region is
demostrated. This research used rainfall data collected during the period 1961-2021. The result suggest
a relationship between ENSO epochs and behavior of rainfall observed in the study area, further analysis
show tha ENSO factor effects parallel on rainfall like other factors such as deforestation. The study of
ENSO-Rainfall cycle also focused on the relevance of numerous generalized autoregressive conditional
heteroskedasticity GARCH model is suitable to analyze its behavior for estimating forecast evolution of
ENSO Rainfall cycle. The GARCH(1,1) model is used for ensuring the appropriateness of autoregression
conditional heteroscedasticity effect on rainfall and ENSO cycle. We take different value of
autoregression and moving averages including (3,1) and (3,3) but an ARMA(6,6)-GARCH(1,1) is used
most of the time. The data is observed till we achieve the convergence after specific iteration and the
coefficient covariance computed using outer product of gradient.