Storm Runoff Estimation Using an Object Oriented Approach Based on the Concepts of System Dynamics

Developing nations are imposing the increasing impacts on their bio-resources due in part to their rising population, need to high economic growth and the incorporation of non-native technologies. Usually, watersheds are the major units, which are influenced leading to un-sustainability, specifically from the view point of water resources and hydrologic systems. Relying on a linear causal thinking, most of the hydrologic models fail to incorporate socioeconomic attributes of a watershed with its hydrologic and environmental ones. Based on a systems thinking philosophy, this paper aims to adopt an object-oriented approach based on the concepts of System Dynamics (SD) to analyze the dynamics in a hydrologic system in a watershed scale. This research focuses on a storm event and investigates the interaction between key elements of rainfall-runoff phenomenon. The paper adopts the concepts of SD such as stocks and flows to define objects in an OO-SD model. The results of the study show that this approach is capable of simulating rainfall runoff process and estimate the value of peak flow exactly. Also the model was compared with HEC-HMS and results showed that using Snyder method for HEC-HMS the exact value of peak flow is obtained for both events. The simplicity of the adopted methodology in this study doesn't limit the accuracy of runoff peak estimation.