涔水南支小流域山洪风险图编制

Flash Flood Risk Mapping for the Watershed of South Branch of Censhui River

山洪风险图是山丘区洪水防治重要的非工程措施之一。以涔水南支小流域山洪风险图编制为例,从编制思路、危险性评估、易损性评估、风险评估以及风险图绘制等方面,对涔水南支小流域山洪风险图编制试点工作的思路、流程及成果进行分析,提出了山洪风险图编制过程中需要明确重点河(沟)段、重要城镇、集镇和村组(社)等居民点及其重要基础设施;需要合理地确定山洪计算标准;分析方法应当根据资料详细程度和编制目标进行选择;山洪风险指标体系及阈值划分需要概化和有针对性;山洪风险图编制可考虑分级分阶段推进等编制要求。

Flash flood risk map is one of the important nonstructural measures for flash flood prevention and control in mountainous areas. Taking the South Censhui River Watershed as an example, this paper systematically introduces the approaches, procedures and outputs in the pilot trial from the aspects of mapping methodology, hazard analysis, vulnerability assessment, risk estimation, and risk mapping. The conclusions include： （1） flash flood risk map is composed of a series maps and corresponding information should be highlighted in each type of maps; （2） the object of flash flood risk mapping should be focused on the residential areas （important river reaches, towns, villages） and fundamental infrastructures in the watershed; （3） reasonable standards for flash flood hydrological analysis are required for flash flood risk mapping; （4） the selection of method for hazard analysis is based on the level of data details and objectives of flash flood risk mapping; （5） the indexes for flash flood risk and their grading need to be simplified and targeted; and （6） it is practical that flood risk mapping is carried out at different levels by stages.