基于GIS和遥感数据的洪水风险分析

随着城市化进程的不断深化，洪涝灾害已经成为威胁人类生存的一种主要自然灾害。人们逐步认识到，仅仅使用工程措施来防御洪水是远远不够的，非工程措施近年来已进入到防洪领域。管理洪水、分析洪水灾害是非工程措施的一个重要方面。应用GIS工具研究ASAR数据和DEM数据获取研究区域的水深信息。以东洞庭湖区域为研究对象，运用3种常用的插值方法（IDW、Kriging和Topo to Raster）进行水面插值．但这些方法的插值效果不是很好。一种新的插值方法（ADDM，基于平均距离插值方法）被用来进行水面插值。相互比较的结果表明，ADDM方法在水深精度和水面连续性方面都优于其他3种方法。最后，根据ADDM方法获取的水深信息和洪水频率图制作东洞庭湖区洪水风险图。

Flood Hazard Analysis Based on GIS and Remote Sensing Data

With the increasing population and the development in flood prone areas, floods have become major .society disrupting disasters. It is realized that flood defending is not the best way to survive from the flooding. In addition to structural measures, the non-structural measures have been introduced to control flooding in recent years. ASAR data and DEM file are used to extract water depth data using GIS tools. Three common interpolation algorithms （ IDW, Kriging and Topo to Raster） have been used to interpolate points with elevation into water surfaces. However, the results from these methods are not satisfactory and therefore a new interpolation algorithm ADDM （Average distance dependent method） has been developed to solve this problem. Comparisons between the results of ADDM and the three common methods are carried out in the research. The results show that the new developed ADDM method is better than the other three methods, whatever on the water depth distribution or on the continuity of the water surfaces. Hence the new method can be used as a more reliable procedure to interpolate the points in case are elevations were extracted from a coarse DEM. All the four algorithms have been tested on a case study using real-life data. The flood hazard map of Dongting Lake is generated based on the water depth results developed by ADDM and flood frequency. It is proved that ASAR images and 90 m × 90 m DEM are capable of developing flood hazard map.