以对中国的洪涝灾害监测评估为例，介绍了以遥感与GIS支持下的基于网络环境的洪涝灾害监测评估关键技术系统的工作环境、关键技术流程和技术方法。该关键技术系统以遥感和GIS为基础，快速将多源数据复合、通过网络集成了多种技术成果和数据，进行快速、准确，连续，动态与全天候的洪涝灾害的监测与评估，为有关部门快速了解灾情、制定救灾方案以及灾后规划等提供了重要的痴情支持手段，已在抗洪救灾工作中发挥了重要作用。

Flood is the disaster most frequently occurring every year in China. How to monitor and evaluate the flood assures the objectivity￡?accuracy and efficiency by new technologies￡?It?ˉs the most urgent problem for Chinese government and experts to deal with. The Institute of Remote Sensing Applications of CAS and China State Information Center have developed Network-Based Flood Disaster?ˉs Monitoring and Evaluating System Using Remote Sensing and GIS. The system includes three parts￡o 1. Flood Disaster Information Generation subsystem 2. Flood Disaster Information Service subsystem 3. Network User subsystem This System has been applicated in monitoring and evaluating flood disasters in China during 1997?a1999. It plays an important role in flood control and disaster mitigation￡?especially in floods occruing along Yangtze￡?Songhua and Nen Rivers in 1998. Up to now￡?131 flood information reports with flood images￡?maps and tables for the flooded areas are provided to the State Council￡?relevant ministries and provincial governments. User can browse￡?query and download the flood information through Internet by permission. This paper introduces the work environment￡?the flow of key techniques and its methodology of the system￡?and gives some application examples.