全国洪涝灾害警戒水域遥感数据库的研制

Development of normal water extent database for the seven-river basins of China based on remote sensing

由于以往对发生的洪涝灾情没有形成统一的、客观的评价标准,而不同来源的各种数据往往大相径庭,使有关部门难以了解实际灾情。为此,提出了"警戒水域"的概念,利用TM和NOAA/AVHRR图像数据建立了我国七大江河地区洪涝灾害易发区的警戒水域遥感数据库,并用以指导洪涝灾情的监测与评估,为防洪救灾决策提供科学的、可靠的、时效性强的信息。该数据库的建立在我国的抗洪救灾中发挥了重要的作用。文章对其研究方法与其关键技术进行了介绍.

With the development of remote sensing technology, scientists have found some effective approaches to monitor floods in a large scale. However, in their researches, there is no any standard to be used for flood assessment. A promising approach is to establish the standard for assessment according to each flooding area. To do so,the concept of 'normal water extent' is put forward in this paper. 'normal water extent' means the minimal values for the assessment of flood losses, and it refers to some special areas according to the situations around the areas of river, lake, reservoir and dyke,and to the land use and etc., which are easy to suffer from flood during the flood season. When the water extent surpasses this normal extent, it will cause some losses of economy.The basic data for 'normal water extent' are TM or NOAA/AVHRR images. In order to get 'normal water extent', it is necessary to identify them by automatic extraction or humancomputer interactive interpretation according to different images, then integrate the normal water extent for each flooding area into a database, which can be called 'normal water extent database' (NWED) with some related spatial data, remote sensing images and attribution data. In this study, NWED for sevenlargeriver basin area in China was set up, and it was utilized for monitoring the floods in China since 1999. The assessment results were applied in several government ministries of China, such as State Planning Committee, Civil Administration Ministry etc. The application shows that, it can improve the efficiency of flood assessment and accuracy of flood information, unify the criteria of its assessment. The study indicates that NWED can be used as a feasible standard of assessment for floods. In this paper, how to set up a normal water extent database and how to use it to monitor flood is introduced in detail. 