Ecological benefit evaluation of reef building engineering of retired oil platforms based on comprehensive weight method

XUE Yu; ZHENG Xilai; YUE Xinhang

doi:10.13984/j.cnki.cn37-1141.2026.01.019

Abstract：When applying the fuzzy comprehensive evaluation method to ecological evaluation,the ana-lytic hierarchy process is often used to determine the weight of each evaluation factor.This method has a subjective error and the evaluation result has uncertainty.The comprehensive weight method combi-ning AHP and entropy weight is adopted,and the subjective and objective weights are combined and calculated based on the principle of minimum information entropy.The obtained comprehensive weight can not only take into account of the subjective intention of decision-making but also take into account of the objectivity of the survey data,which conforms to the requirements of the optimization model for factor weight.In this paper,the ecological benefit evaluation index system of the decommissioned oil platform reef-building was constructed,and the fuzzy comprehensive evaluation model was established based on the comprehensive weight of the evaluation index and applied to the ecological environmental benefit evaluation of the platform reef-building demonstration project in Chengdao sea area.The eco-logical evaluation result obtained after the weight determined by AHP was Grade Ⅱ,which was incon-sistent with the Grade Ⅰ evaluation result obtained by the entropy weight method.The evaluation re-sults of the comprehensive weight method showed that the surveyed sea area was at level Ⅱ ecological level as a whole,and the ecological benefit score of the reef-building area(1#～4#)was 0.784 on av-erage,which was higher than the ecological benefit score of the non-reef area(5#)0.751,indicating that the platform reef building project had a good ecological restoration effect for the sea area.