Comparative study of environmental impact assessment methods along with a new dynamic system-based method

Environmental Impacts Assessment has been developed as a critically substantial approach to determine, predict and interpret the ecological impact on the environment, public hygiene and healthy ecosystems. This study aims to introduce and systematically investigate the environmental issues during important decision-making stages. Meanwhile, impacts of development on the environmental components will be also analyzed. This research studies various methods of predicting the environmental changes and determining the impacts through both qualitative and quantitative methods. Qualitative approaches rely fully upon the expert's decisions, while quantitative ones are entirely based on mathematical methods where the relations between the elements are expressed through variables and parameters. Then both approaches required be comparing and contrasting. Among these methods, expertise method, check list, matrix, overlaying maps and networks are crucially considerable. These methods, based on the static variables, mostly describe the relations which are constant over time. The most important objective of this study is providing a dynamic model of the environmental assessment based on dynamic variables. Such a model can define changeable relations. Therefore, to present a new model based on system dynamics, the environmental components and changes due to the project have been considered as a set of interrelated elements and variables. There are some variables as input element whose interrelations and mutual effects are considered as a process which leads to the output of the system. This research investigates the existing dynamism among the components affecting the environmental assessment. Static and single function systems cannot make real simulation. Thus, this research benefits from dynamic systems that can display multifunctional structures, model nonlinear and time delays, as a means of Environmental Impacts Assessment.