Theme-8-5-Impact of afforestation on smart flows.

Abstract

Effect of afforestation on storm flows for a catchment situated between the lower Himalayan and Shivalik ranges has been investigated. The catchment is shoe—shaped and encompasses an area of 3076 sq.kms. It is drained by river Ramganga and its tributaries. The area has been treated with eucalyptus and pine plantation. A least squares regression is suggested to estimate daily storm flow volumes from daily rainfall events after analysing the data for six sub basins for the five years period prior to the afforestation and for the five years of post treatment period for events larger than 10mm of mean daily rainfall. The results from the study indicate a decrease of 11% to 36% in the daily storm flow volumes for the post treatment in the five sub basins. However, there is no significant change in one of the sub basins. The flow duration curves are also presented for the catchment. The decrease in mean daily peak flow which is available for 10% of time is by 15% and the mean daily flow has decreased by 37%.