Nitrogen Emissions-Based Assessment of Anthropogenic Regional Ecological Risk: An Example of Taiwanese Urbanization, 1990–2015

This study proposes a framework for evaluating anthropogenic nitrogen emissions and local vulnerability in order to assess regional ecological risk of human activity during a stable urbanization process. Taiwan, an isolated island with a unique environment, intensive agriculture, concentrated industries, and stable urbanization, was an ideal location for testing this framework. Local vulnerability is influenced by social characteristics, economic development, environmental protection, and other indicators related to these. Within the context of urbanization, therefore, and using official statistical data, human metabolism, agricultural and industrial production, and transportation were evaluated. The results indicate that the rate of anthropogenic nitrogen emissions decreased as the process of urbanization in Taiwan stabilized. While nitrogen emissions from agricultural production, household and industrial wastewater gradually decreased due to a reduction in the area of arable farmland, a reduction in the use of fertilizers and increased sewage treatment, nitrogen emissions from transportation increased due to higher energy consumption from vehicle use. Taiwan exhibited a higher degree of regional vulnerability in 1998 because motor vehicle density increased significantly, while rates of per capita green area and resource recovery remained relatively low. The study found that if Taiwan maintains its current conditions with respect to standard of living, agriculture, industry, and transportation, nitrogen emissions from human metabolism and agricultural and industrial production will not increase regional ecological risk, while nitrogen emissions from transportation will likely increase this risk. Therefore, this paper suggests that future environmental planning in Taiwan should prioritize low-emissions sustainable transportation.