Development of relationship between glacier melt runoff and meteorological parameters – A research report by National Institute of Hydrology

The study attempts to develop a relationship between glacier melt runoff and meteorological parameters for the Dokriani glacier in Garhwal Himalayas. The discharge auto-correlation, correlation between discharge & temperature and between discharge & rainfall has been computed for each month of the summer season and for the melt season as a whole for different years.

The correlation and auto-correlation coefficients vary from year to year for a period because of changes in weather conditions and physical characteristics of the glacier. The occurrence of higher rainfall in the months of July and August lowers the discharge auto-correlation, and correlation between the discharge and temperature, but improves the discharge and rainfall correlation.

The discharge auto-correlation, discharge and temperature correlation are observed to be maximum in the months of June and September. The occurrence of lower rainfall, systematic melting environment, stronger storage characteristics are responsible for this higher correlation for these months.

The monthly and seasonal distribution of discharge auto-correlation for different years suggests that although the discharge auto-correlation is very good with all considered lags, but auto-correlation for lag1 day (Q_i-1) is relatively higher for all the months and through all the years. On the monthly basis, maximum discharge auto-correlation with Q _i-1 ranged from 0.61 and 0.97 for different years, while on the seasonal basis it varied from 0.83 to 0.95. It shows that for the forecasting of discharge for a particular day from the glaciarised basin, previous day discharge becomes a significant predictor.

The discharge auto-correlation coefficient decreases with an increase in the lag period of discharge both on monthly and seasonal basis.  However, reduction in value of r with an increase in discharge time lag on the monthly basis is higher than that on the seasonal basis.

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