Determination of surface drainage coefficient - a case study of Doimukh (Arunachal Pradesh), India

Abstract

In this study, 1 day to 7 consecutive days annual maximum rainfall was predicted at various return periods using probability distribution functions for Doimukh (Arunachal Pradesh), India. Basic infiltration (Ib) rate value was estimated 10 mm hr^-1 for the agricultural field having sandy soil. The drainage coefficient was estimated for 5, 10, 20 and 25 years R.I. by subtracting basic infiltration rate from estimated consecutive day rainfall.  For the study area, the maximum value of drainage coefficient at 25 years recurrence interval varied from 41.37 mm day^-1 to 304.23 mm day^-1 for 2 to 7days consecutive rainfall. The minimum value of drainage coefficient at 5 years interval varied from 0 to 212.30 mm day^-1 for 2 to7days consecutive rainfall. Study concluded that sandy soil of Doimukh (Arunachal Pradesh) having basic infiltration rate 10 mm hr^-1 had to be provided with agricultural drainage for its major crops grown in the area.