A GIS-based flash flood runoff model using high resolution DEM and meteorological data

Natural hazards are historically a substantial threat to the progress and development of human communities. Floods hold a dominant position among these specific phenomena due to their fre-quent occurrence as well as their large spatial spread. Certainly, the aforementioned facts become more visible under the light of the assessment of the dramatic effects brought about by their occur-rence. Consequently, the need to deal with the impact of floods on human communities with an effective way leads to a systematic involvement of the international scientific community on the subject of "Management of Natural Hazards".
The present study describes an attempt to model surface runoff in a typical ungauged basin, which is directly related to catastrophic flood events, by creating a system based on GIS technology. The main object was to construct a direct unit hydrograph for an excess rainfall by estimating the stream flow response at the outlet of a watershed. Specifically, the methodology was based on the creation of a spatial database in GIS environment and on data editing. Moreover, rainfall time-series data came from Hellenic National Meteorological Service and they were processed in order to calculate flow time and the runoff volume. Apart from the meteorological data, background data such as topography, drainage network, land cover and geological data were also collected. A high resolution DEM was of great importance in order to achieve the final result. The study area is the sub-basin of Archaia Olympia (Kladeos sub-basin) in Greece, and the examined event occurred on February 5th, 2012.

长期以来，自然灾害对人类社会的进步与发展构成严重威胁。其中洪涝灾害因频发且波及范围广，在各类自然灾害中占据主导地位。毋庸置疑，通过评估洪涝灾害发生所带来的严重影响，上述特征会更为凸显。因此，为有效应对洪涝灾害对人类社会造成的影响，国际科学界开始系统性地参与到“自然灾害管理”这一研究主题中。

本研究尝试基于地理信息系统(GIS)搭建相关系统，对与灾难性洪涝事件直接相关的典型无资料流域的地表径流进行模拟。本研究的核心目标是通过估算流域出口断面的径流响应，推求净雨对应的直接单位线。具体而言，本研究的方法基于地理信息系统环境下空间数据库的构建与数据整编。此外，本研究使用的降雨时序数据源自希腊国家气象局，经处理后用于计算汇流时间与径流量。除气象数据外，本研究还收集了地形、水系、土地覆被与地质等基础背景数据。高分辨率数字高程模型(DEM)对最终研究成果的获取至关重要。本研究的研究区域为希腊的阿尔卡亚·奥林匹亚子流域（克拉德奥斯子流域），所分析的洪涝事件发生于2012年2月5日。