摘要
過去許多研究嘗試用模型量化從陸地排放入海的垃圾量，而大部分都是仰賴使用全球估算的人口密度，作為預測環境中的垃圾的關鍵要素。本研究使用在七國不同國家（中國、肯亞、南非、南韓、斯里蘭卡、台灣與越南）所蒐集的實證數據，來評估多種可能影響塑膠逸散到環境的不同因素。這些因素包含全球可用的地理資訊系統資料，以及在地所做的觀察。而最佳模型的主要變因依地而異，因此，我們的分析明確指出，人口密度不是塑膠逸散到環境中的最佳指標。相較於人口密度，其他像是土地使用、基礎建設、社經條件，與在地的變因（例如是否有可見的人為活動、植群高度、樣區類型等），皆與環境中的塑膠垃圾有更強的相關性。本研究強調蒐集實證數據與建立定期監測的重要性，不只能更準備的估算排放入海的陸源垃圾，更能評估陸域對策的有效性。
Abstract
There have been a variety of attempts to model and quantify the amount of land-based waste entering the world’s oceans, most of which rely heavily on global estimates of population density as the key driving factor. Using empirical data collected in seven different countries/territories (China, Kenya, South Africa, South Korea, Sri Lanka, Taiwan and Vietnam), we assessed a variety of different factors that may drive plastic leakage to the environment. These factors included both globally available GIS data as well as observations made at a site level. While the driving factors that appear in the best models varied from country to country, it is clear from our analyses that population density is not the best predictor of plastic leakage to the environment. Factors such as land use, infrastructure and socio-economics, as well as local site-level variables (e.g., visible humans, vegetation height, site type) were more strongly correlated with plastic in the environment than was population density. This work highlights the importance of gathering empirical data and establishing regular monitoring programs not only to form accurate estimates of land-based waste entering the ocean, but also to be able to evaluate the effectiveness of land-based interventions.
Schuyler, Q., Wilcox, C., Lawson, T. J., Ranatunga, R. R. M. K. P., Hu, C. S., & Hardesty, B. D. (2021). Human population density is a poor predictor of debris in the environment. Frontiers in Environmental Science, 9, 133.