Fluvial floods are one of the primary natural hazards to our society, and the associated flood risk should always be evaluated for present and future conditions. The European Union’s (EU) Floods Directive highlights the importance of flood mapping as a key stage for detecting vulnerable areas, assessing floods’ impacts, and identifying damages and compensation plans. The implementation of the EU Flood Directive in Greece is challenging because of its geophysical and climatic variability and diverse hydrologic and hydraulic conditions. This study addressed this challenge by modeling of design rainfall at the sub-watershed level and subsequent estimation of flood design hydrographs using the Natural Resources Conservation Service (NRCS) Unit Hydrograph Procedure. The HEC-RAS 2D model was used for flood routing, estimation of flood attributes (i.e., water depths and flow velocities), and mapping of inundated areas. The modeling approach was applied at two complex and ungauged representative basins: The Lake Pamvotida basin located in the Epirus Region of the wet Western Greece, and the Pinios River basin located in the Thessaly Region of the drier Central Greece, a basin with a complex dendritic hydrographic system, expanding to more than 1188 river-km. The proposed modeling approach aimed at better estimation and mapping of flood inundation areas including relative uncertainties and providing guidance to professionals and academics.

中文翻译：

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湖泊和大型流域城乡洪水泛滥建模方法

河流洪水是对我们社会的主要自然灾害之一，因此应始终针对当前和未来状况评估相关的洪水风险。欧盟（EU）洪水指令强调了洪水绘图的重要性，这是检测脆弱区域，评估洪水影响以及确定损害和赔偿计划的关键阶段。由于希腊的地球物理和气候多变性以及多样的水文和水力条件，因此在希腊实施欧盟洪水指令具有挑战性。这项研究通过对子流域一级的设计降雨进行建模并随后使用自然资源保护局（NRCS）单位水文程序估算洪水设计水文来应对这一挑战。HEC-RAS 2D模型用于洪水路由，洪水属性估算（即，水深和流速），以及淹没区域的地图绘制。建模方法应用于两个复杂且未开放的代表性盆地：位于潮湿的西希腊伊庇鲁斯地区的帕姆沃蒂达湖盆地，以及位于较干燥的希腊中部较干燥的希腊萨萨利地区的皮尼奥斯河盆地，这是一个复杂的树枝状盆地。水文系统，扩大到1188多公里。拟议的建模方法旨在更好地估计和淹没洪水泛滥区，包括相对不确定性，并为专业人士和学者提供指导。位于希腊中部较干燥地区的色萨利地区的皮尼奥斯河盆地，一个具有复杂的树状水文系统的盆地，延伸至1188多公里。拟议的建模方法旨在更好地估计和淹没洪水泛滥区，包括相对不确定性，并为专业人士和学者提供指导。位于希腊中部较干燥地区的色萨利地区的皮尼奥斯河盆地，一个具有复杂的树状水文系统的盆地，延伸至1188多公里。拟议的建模方法旨在更好地估计和淹没洪水泛滥区，包括相对不确定性，并为专业人士和学者提供指导。