A Comparative Analysis of Estimating an Optimum Tank Size for RWH using Decision Support System and Unsupervised Classification Approach

Water is the matchless gift of the living being and it is the basic necessity of life. The universal atmosphere is fluctuating day to day, due to the high indulgence and negligence of human being with nature. As a result of that the water resources/reservoirs are draining gradually and People across the world is facing severe drought condition. In India, one-third of the region is claimed to be drought-prone and several thousand regions do not have drinking water due to the unpredictable climatic condition. Rainwater harvesting (RWH) is an effective approach to resolve the water scarcity in India. Setting up of an RWH plant is easy, but it requires proper understanding, suitable methods, as well as suitable to everyone. This paper, expresses a general way for selecting suitable rooftop rainwater harvesting sites and to construct an efficient harvesting plant with proper decision support system using QGIS tool and Google Earth Pro software. It also assesses rooftop runoff harvesting with geospatial techniques using an unsupervised classification approach to build a reservoir/tank size to increase the ground water level and to calculate tank capacity. A comparative analysis of two methods helps to understand the more efficient and accurate way of designing the rainwater harvesting plant and in calculating the tank capacity.