為實施中油公司永安廠液化天然氣專用接收站的社區風險( societal risk )評估，乃同時進行本研究，對緊鄰並環繞接收站的新港村、永安村、永華村及舊港村，作人口結構調查分析。首先設計調查表，實施樣本調查。再以電腦統計調查資料，並參考政府機關的人口普查資料，而獲得下列結果:
3.夜間人口數與普查人口總數的關係:普查人口總數是夜間人數的74%。但此百分比因只調查4村，故僅供參考，不能作為日後預估的基準。這些調查結果與英國類似的調查比較，發現互有雷同近似之處。本研究因限於人力，物力，故未實施其他更細部的調查[如扇形區( sectors )調查]。 In order to in clude a termination of the societal risk, population composifions form four villages around Yung An LNG Terminal were investigated and then analyzed. A household composition table was designed in the various categories of an household. Household samples were taken and processed into computer. The analyses were aided by the local sensus enumeration district data. The results of the study are:
1. each household composition is found,
2. the vulnerable category accounts for 20.35% of night-time population; daytime population is47.95% of night-time population, and
3. census population is 74% of night-time population.
The value may not be a good basis or future prediction because of limited samples selected.
Compared with England similar analyses, these results are found to be very close to England data.
Further datailed investigations, for example, each sector,s investigation, are abandoned bcause of the constraints of available support, and consequently a fewer residential areas and items are included in this stvdy.