化学事故具有突发性强、环境污染破坏严重、救援难度大等特点,对突发化学事故的影响范围、破坏程度进行快速评估,为事故抢险救援提供决策支持,是应对重特大突发化学事故、降低事故损失的重要手段。本文基于三维地理信息系统(Three-dimen...化学事故具有突发性强、环境污染破坏严重、救援难度大等特点,对突发化学事故的影响范围、破坏程度进行快速评估,为事故抢险救援提供决策支持,是应对重特大突发化学事故、降低事故损失的重要手段。本文基于三维地理信息系统(Three-dimensional Geographic Information System,3D GIS),在充分考虑下垫面影响的前提下,研究了大气污染扩散模型,提出了扩散场快速构建技术及兼顾污染分区的救援力量调度方法,并以此为核心建立了系统总体框架,形成了集扩散模拟、危害分析、救援调度等功能于一体的突发化学事故危害评估与救援辅助决策支持系统,可为突发化学事故危害后果评估与辅助救援决策提供有效的技术支撑。展开更多
Based on a coupled hydrodynamic–ecological model for regional and shelf seas (COHERENS), a three-dimensional baroclinic model for the Changjiang (Yangtze) River estuary and the adjacent sea area was established using...Based on a coupled hydrodynamic–ecological model for regional and shelf seas (COHERENS), a three-dimensional baroclinic model for the Changjiang (Yangtze) River estuary and the adjacent sea area was established using the sigma-coordinate in the vertical direction and spherical coordinate in the horizontal direction. In the study, changing-grid technology and the "dry-wet" method were designed to deal with the moving boundary. The minimum water depth limit condition was introduced for numerical simulation stability and to avoid producing negative depths in the shallow water areas. Using the Eulerian transport approaches included in COHERENS for the advection and dispersion of dissolved pollutants, numerical simulation of dissolved pollutant transport and diffusion in the Changjiang River estuary were carried out. The mass centre track of dissolved pollutants released from outlets in the south branch of the Changjiang River estuary water course has the characteristic of reverse current motion in the inner water course and clockwise motion offshore. In the transition area, water transport is a combination of the two types of motion. In a sewage-discharge numerical experiment, it is found that there are mainly two kinds of pollution distribution forms: one is a single nuclear structure and the other is a double nuclear (dinuclear) structure in the turbid zone of the Changjiang River estuary. The rate of expansion of the dissolved pollutant distribution decreased gradually. The results of the numerical experiment indicate that the maximum turbid zone of the Changjiang River estuary is also the zone enriched with pollutants. Backward pollutant flow occurs in the north branch of the estuary, which is similar to the backward salt water flow, and the backward flow of pollutants released upstream is more obvious.展开更多
文摘化学事故具有突发性强、环境污染破坏严重、救援难度大等特点,对突发化学事故的影响范围、破坏程度进行快速评估,为事故抢险救援提供决策支持,是应对重特大突发化学事故、降低事故损失的重要手段。本文基于三维地理信息系统(Three-dimensional Geographic Information System,3D GIS),在充分考虑下垫面影响的前提下,研究了大气污染扩散模型,提出了扩散场快速构建技术及兼顾污染分区的救援力量调度方法,并以此为核心建立了系统总体框架,形成了集扩散模拟、危害分析、救援调度等功能于一体的突发化学事故危害评估与救援辅助决策支持系统,可为突发化学事故危害后果评估与辅助救援决策提供有效的技术支撑。
基金Supported by the Public Welfare Special Scientific Research Project funded by the Ministry of Water Resources of China (No. 200701026)National Natural Science Foundation of China (No. 50709007)the Startup Fund of Hohai University (No. 2084/40801107)
文摘Based on a coupled hydrodynamic–ecological model for regional and shelf seas (COHERENS), a three-dimensional baroclinic model for the Changjiang (Yangtze) River estuary and the adjacent sea area was established using the sigma-coordinate in the vertical direction and spherical coordinate in the horizontal direction. In the study, changing-grid technology and the "dry-wet" method were designed to deal with the moving boundary. The minimum water depth limit condition was introduced for numerical simulation stability and to avoid producing negative depths in the shallow water areas. Using the Eulerian transport approaches included in COHERENS for the advection and dispersion of dissolved pollutants, numerical simulation of dissolved pollutant transport and diffusion in the Changjiang River estuary were carried out. The mass centre track of dissolved pollutants released from outlets in the south branch of the Changjiang River estuary water course has the characteristic of reverse current motion in the inner water course and clockwise motion offshore. In the transition area, water transport is a combination of the two types of motion. In a sewage-discharge numerical experiment, it is found that there are mainly two kinds of pollution distribution forms: one is a single nuclear structure and the other is a double nuclear (dinuclear) structure in the turbid zone of the Changjiang River estuary. The rate of expansion of the dissolved pollutant distribution decreased gradually. The results of the numerical experiment indicate that the maximum turbid zone of the Changjiang River estuary is also the zone enriched with pollutants. Backward pollutant flow occurs in the north branch of the estuary, which is similar to the backward salt water flow, and the backward flow of pollutants released upstream is more obvious.
