中文摘要：

数字西江水质预警预报系统是一个以地理信息系统（GIS）和数据库管理系统（DBMS）为开发平台，面向管理和决策层的可视化动态信息系统，采用集成GIS组件和水量水质数值模型的耦合方式。本系统一方面建立基于GIS的水环境评价、水环境容量计算和污染物总量控制。另一方面在发生水污染突发事故后，能够快速预报污染物向下游的扩散时间、扩散面积、确定污染范围、污染程度及对下游取水口等所造成的影响，为决策部门提供决策支持。

英文摘要：

The system of water quality pre-waming and forecast of Xi River is a visual dynamic information system, which is developed on the platform of GIS and DBMS, oriented to the management and decision-making level, using the coupling method of integrated GIS module and water quantity-quality numerical model. On the one hand, the system has established the water environment evaluation, water environmental carrying capacity estimation, and the total quantity of pollutants control based on GIS; on the other hand, if the water pollution happens, the system can forecast the diffusion time, diffusion area of contaminant quickly, and determine the pollution area, the pollution degree and its in fluence on the water inlets downstream to provide the decision support for the decision makers.