Environmental impact assessment refers to the investigation, prediction and evaluation of what impact the plan or project will have on the atmosphere, water, soil, organisms and the environmental system composed of them, and what impact the results of these impacts will have on human health and living environment, as well as the natural environment, economy, culture and historical environment, Based on this, the countermeasures and measures to prevent or reduce environmental pollution and damage are formulated.
After the viaduct was built in a city, residents of several nearby buildings reported that the bridge seriously affected the daylighting. The municipal government organized relevant departments to evaluate it to decide how to deal with it belongs to environmental impact assessment according to the above definition.