This project belongs to the field of environmental emergency management technology research in the environmental protection sector. Environmental risk sources are characterized by complex chemical compositions and wide distribution. Leaks, explosions, etc., caused by these sources can lead to the dispersion of pollutants with water flow and atmosphere, posing serious threats to sensitive targets such as water sources and residential areas; the technical difficulty lies in how to scientifically predict environmental risks and make effective emergency decisions after sudden accidents occur. This project focuses on comprehensive response to water and air environmental risks, aiming to achieve effective supervision before the event, scientific prediction and judgment during the event, and efficient emergency decision-making. It has developed key technologies for risk assessment and early warning decision-making in sudden environmental incidents. The project has the following innovations: 1. Established a technology for assessing sudden environmental risks based on the evolution process from environmental risk to environmental accident. In response to the shortcomings of existing domestic and international environmental risk assessment methods, which only focus on evaluating the risk sources themselves, this project innovatively proposes a method that starts with source term factors, The environmental risk of a company is evaluated from three aspects: process factors, receptor factors, and general evaluation models that lack process factors to reflect the production processes and management levels of enterprises, making the assessment of sudden environmental risks more scientific; on this basis, an environmental risk map for Shanghai was drawn. 2. Developed a coupled risk field and emergency decision-making model system for river network systems - water sources - raw water transmission pipelines. Developed experimental simulation technology for the coupling process of water flow - suspended sediments - toxic pollutants, solving the problem of difficultly accurately determining model parameters for chemical transport in long-distance channels; developed mathematical models representing different spatial scale characteristics of river network systems - water source bodies at multiple scales, as well as coupled sedimentation / chemical fields under the influence of sudden pollution in water sources. The powdered activated carbon (PAC) - pollutant dynamic adsorption and sedimentation mathematical model was applied in the raw water delivery channel, achieving precise prediction of risk fields for river networks, water sources, and water plants, as well as emergency water supply decision support. 3. A chemical leakage atmospheric pollution risk field and pollution tracing model system was developed. Based on the characteristics of different density air masses, the system developed light gas, medium-density gas, and heavy gas diffusion models for chemical leakage in the atmosphere, as well as pool fire models, jet fire models, fireball models, and steam cloud explosion models under conditions of fire and explosion; a sudden air pollution tracing model system based on real-time online data of meteorology and pollutant concentrations was developed, providing technical methods for quickly inferring the possible range and source strength of unknown sources in emergency accident situations, solving the problem of source location with limited monitoring points. 4. A model system based on B/S, C/S, A digital platform for emergency decision-making in sudden environmental events with a mixed M/S architecture. It addresses the needs of 'normal' environmental risk management and 'wartime' rapid emergency response decision-making, achieving a 'three combination' of synchronous and asynchronous applications, online and offline services, business data and spatial data, and effectively integrating the environmental risk source database and water and gas risk field model system. It synchronizes on-site disposal with command platform emergency decision-making analysis, significantly improving the level of environmental emergency decision-making. Published 28 papers, including 14 SCI and EI papers, obtained 1 authorized invention patent, and 9 authorized computer software copyrights. Won 1 Silver Award for Excellent Engineering in China's Geographic Information Industry (2011), and won the Zhou Peiyuan Hydrodynamics Prize (2012). The environmental emergency management and decision-making system platform has been applied in the Shanghai Environmental Protection Bureau, Minhang District Environmental Protection Bureau, The Emergency Response Coordination Center of Minhang District and other district-level units have been deployed and applied, providing support for the environmental safety assurance and emergency response to unexpected incidents during the World Expo. Technical guidelines such as 'Guidelines for the Compilation of Environmental Incident Risk Assessment Reports for Enterprises in Shanghai (Trial)' and 'Guidelines for the Compilation of Emergency Plans for Sudden Environmental Incidents in Enterprises and Institutions in Shanghai (Trial)', along with a technical method, have been compiled and issued for implementation by the Shanghai Municipal Bureau of Environmental Protection. This project has promoted Shanghai's environmental emergency management to be at the forefront of the country and has significant reference value for China's environmental risk prevention.