镇朔湖拦洪库行洪风险分析与超标准洪水防御措施研究

Research on Flood Discharge Risk Analysis and Super-Standard Flood Protection Measures for Zhenshuo Lake Flood Detention Reservoir

摘要: 我国流域超标准洪水应对问题突出，在气候变化、人类活动等影响下，面临规律重新认知、技术亟需提升和措施体系亟待完善等重大挑战。本文以宁夏石嘴山市平罗县镇朔湖拦洪库为例，基于宁夏回族自治区水旱灾害防御中心提供的基础研究数据，采用瞬时单位线法、水力学原理和比降面积法等方法，对研究区各沟道和拦洪库的行洪能力和防洪标准进行计算，并得出：镇朔湖的设计防洪标准为20年一遇，洪峰流量为773 m³/s，校核标准为100年一遇，洪峰流量1350 m³/s；小水沟现状基本可满足100年一遇洪水过流能力，北大闸沟桥桥位断面设计洪水釆用小水沟及其南侧小沟沟口汇合后设计洪水，其100年一遇的设计洪峰流量为637 m³/s，能满足镇朔湖拦洪库的进口断面过流能力的需求；结合研究区危险点调研，为镇朔湖拦洪库提出“上拦蓄，下分洪”的山洪防御措施，以此来缓解超标准洪水对拦洪库和危险区人民的危害。该研究提供了超标准洪水致灾风险分析方法，对于防御水库超标准洪水提供了技术支撑。

Abstract: The problem of coping with super-standard floods in China’s river basins is prominent. Under the influence of climate change, human activities, China is faced with major challenges such as re-recognition of laws, and urgent to improve technology and the measure system. Taking the flood detention reservoir of Zhenshuo Lake in Pingluo County, Shizuishan City, Ningxia as an example, based on the fundamental research data provided by the Water and Drought Disaster Defense Center of Ningxia Hui Autonomous Region, this paper calculates the flood carrying capacity and flood control standard of each channel and reservoir in the study area using instantaneous unit hydrograph method, hydraulics principle and gradient area method. It is concluded that the design flood control standard of Zhenshuo Lake is once every 20 years, and the peak flow is 773 m³/s. The check standard is 100-year return period, with peak discharge of 1350 m³/s; The current situation of the small ditches can basically meet the 100-year flood discharge capacity. The design flood of the bridge section of the Beida Zhagou Bridge is the design flood after the confluence of the small ditches and the south side of the small ditches. The 100-year flood peak flow is 637 m³/s, which can meet the demand of the inlet fault surface discharge capacity of Zhenshuo Lake flood detention reservoir; In combination with the research on the vulnerable points in the study area, the mountain flood prevention measures of “upper retaining and lower flood diversion” are proposed for Zhenshuo Lake flood detention reservoir, so as to mitigate the harm of the super standard flood to the flood detention reservoir and the people in the area. This study provides an analysis method of disaster risk caused by super standard flood, which has important guiding significance for flood management under super standard flood conditions.