Proposal of simple and reasonable method for design of rainwater harvesting system from limited rainfall data

Abstract

Recently, rainwater harvesting (RWH) is gaining interest as an alternative source of safe drinking water especially in developing countries. Getting a detailed and suitable rainfall data to have a good design of RWH system is a challenge in developing countries. In RWH system performance predictions, direct use of monthly rainfall data may lead to considerable error instead of using daily rainfall data. This paper proposes a simple and reasonable design method of rainwater harvesting system from available limited data like monthly rainfall data, which can achieve negligible error and conservative predictions. A RWH model that employs the designed rainfall which generates daily rainfall for each month with distribution of uniformly number of wet days in the last days of month as its input gives performance predictions quite similar to that of using actual daily rainfall.