Analysis of the Runoff Generated due to the 2011 Monsoon Rainfall in Sindh using HEC-HMS

Abstract

An in depth analysis is carried out for the calculation of runoff generated due to the heavy 2011 monsoon rainfall in the South East of Sindh, which luckily also has a very large manmade drainage system operating in the area namely Left Bank Outfall Drain (LBOD). The large runoff created havoc in the area and rain water remained in many areas for months. The calculation of the runoff is carried out with the help of widely used software Hydrologic Engineering Centre’s Hydrologic Modeling System (HEC-HMS). HECHMS version 3.5 was used for the purpose. The rainfall data was obtained from the Pakistan Meteorological Department, Government of Pakistan which records rainfall every 24 hours period. The results show very large amount of runoff due to heavy rainfall which looking at the present capacity of LBOD would take months to drain off.