Simple download service (Atom) of the dataset: Heights of the flooding zone by hydraulic and hydrogeomorphological approach from Sarsonne to Ussel in Corrèze

L_ZI_SARSONNE_2001_H_S_019 The study determined the flooding areas of the Sarsonne at Ussel by hydrogeomorphological approach on the upstream and downstream areas of the urbanised part (maximum right-of-way only). The hydrogeomorphological approach is a naturalistic approach based on reading the morphology of the alluvial plain. It is supplemented here by extrapolation of the water line from a flood known to establish the reference flood water line. This reading of the morphology of the alluvial plain has been clarified on the urbanised area, thanks in particular to topographical works, allowing the definition of heights and flow rates in the crossing of the urbanised area. The flooding zone was determined by calculating the water line of a centennial flood (reference) determined by extrapolation of the 1994 flood water line, extrapolation based on topographical knowledge, the difference in flows between the 1994 event and a centennial event. Topographic knowledge has been used to determine water heights (between 0 and 1 m and > 1 m); flow velocities were defined qualitatively from valley morphology primarily. The crossing of these two parameters allowed to map the hazard (strength = H > 2 m or 1 m < H < 2 m and V > 0.5 m/s or 0 m < H < 1 m and V > 1 m/s; mean = 1 m < H < 2 m and V < 0.5 m/s or 0 m < H < 1 m and 0.5 m/s < V < 1 m/s; low hazard 0 m < H < 1 m and V < 0.5 m/s).L_ZI_SARSONNE_2001_H_S_019 本研究采用水文地貌学方法（hydrogeomorphological approach），不对，修正为：本研究采用水文地貌学方法（hydrogeomorphological approach），针对城市化区域的上下游河段（仅按最大通行用地范围），确定了于塞尔（Ussel）境内萨尔松讷河（Sarsonne）的洪水淹没范围。该方法是一种基于解读冲积平原地貌的自然主义研究手段，本研究通过对已知历史洪水的水位线外推，以此确定基准洪水水位线，对该方法进行补充完善。 得益于地形测绘工作，本研究针对城市化区域的冲积平原地貌解读进行了细化，明确了该区域内的水深与流量参数。本研究结合地形资料、1994年洪水事件与百年一遇洪水事件的流量差值，对1994年洪水水位线进行外推，以此计算得到基准百年一遇洪水的水位线，进而确定洪水淹没范围。研究借助地形资料确定水深范围（0~1米、>1米），流速则主要依据河谷地貌进行定性界定。 结合上述两项参数，可完成洪水危险性等级划分：高危险等级对应水深H>2米，或1米<H<2米且流速V>0.5米/秒，或0米<H<1米且流速V>1米/秒；中等危险等级对应1米<H<2米且流速V<0.5米/秒，或0米<H<1米且0.5米/秒<V<1米/秒；低危险等级对应0米<H<1米且流速V<0.5米/秒。