短时强降水对剑河县城市内涝风险影响分析

城市内涝的发生与气象条件紧密相关,强降水是致灾的关键因素。通过分析把握剑河县城降雨变化趋势,结合城区的易涝点及历史积水资料,得到内涝灾害风险的分布特征及演变规律,进一步开展气象条件致灾关键环节分析,有助于剑河县内涝灾害气象决策服务更加精细化,为加强城市灾害的应急处置和应对防范能力体系建设提供气象支撑。通过对剑河县国家气象观测站2007～2021年降水数据进行分析,剑河县城降水主要集中在4～9月,占全年降水的74.5％,该时段也是剑河县城短时强降水、大雨、暴雨的集中高发期,4～9月大雨以上量级降水出现日数呈增多趋势,近15a来1h最大降水量呈逐年波动增加趋势,且主要发生在4～9月。结合DEM数字高程数据得到的易积水路段点及历史积水内涝资料分析,当短时强降水发生时,县城易积水路段会出现不同程度的积水,当小时雨强达到20mm且未来降水持续时,有积水达到10~20cm的风险,对行人过往造成影响,需加强监测并提示相关部门注意易积水路段可能出现积水风险;小时雨强超过30mm时,有积水超过20cm的风险,对车辆及低洼路段建筑影响较大,需及时联系相关部门建议在易积水路段采取相应排水措施,避免出现积水内涝情况影响居民工作生活,同时开展公众服务建议居民注意出行安全;小时雨强超过50mm时,将出现30cm以上积水,对过往车辆及低洼段建筑影响很大,行驶车辆应当就近到安全区域暂避,避免将车辆停放在低洼易涝等危险区域,如遇严重水浸等危险情况应当立即弃车逃生。相关应急处置部门和抢险单位应当严密监视灾情,做好内涝可能引发的其他灾害应急抢险救灾工作。

Impact of short-term heavy rainfall on urban waterlogging risk in Jianhe Guizhou

The occurrence of urban waterlogging is closely related to meteorological conditions, and heavy precipitation is the key factor causing disasters. By analyzing and grasping the change trend of rainfall in Jianhe County, combined with the waterlogging-prone points and historical water accumulation data in the urban area, we can obtain the distribution characteristics and evolution law of waterlogging disaster risk, and further analyze the key links caused by meteorological conditions, which will help Jianhe County"s waterlogging The disaster meteorological decision-making service is more refined, providing meteorological support for strengthening the construction of urban disaster emergency response and response prevention capability system. Through the analysis of the precipitation data of Jianhe County National Meteorological Observatory from 2007 to 2021, the precipitation in Jianhe County is mainly concentrated in April to September, accounting for 74.5% of the annual precipitation. This period is also the short-term heavy precipitation and heavy rain in Jianhe County. , The concentrated and high incidence period of heavy rain, the number of days with precipitation above the magnitude of heavy rain from April to September showed an increasing trend, and the maximum precipitation in 1 hour in the past 15 years showed an increasing trend year by year, and mainly occurred in April to September. Combined with the analysis of the points of the road sections prone to water accumulation and historical waterlogging data obtained from the DEM digital elevation data, when short-term heavy rainfall occurs, the road sections prone to water accumulation in the county will have water accumulation to varying degrees. When it continues, there is a risk of water accumulation of 10~20cm, which will affect pedestrians in the past. It is necessary to strengthen monitoring and remind relevant departments to pay attention to the risk of water accumulation in road sections that are prone to accumulation of water; when the hourly rain intensity exceeds 30mm, there are cases where the accumulation of water exceeds 20cm. Risks will have a greater impact on vehicles and buildings on low-lying road sections. It is necessary to contact relevant departments in time to recommend corresponding drainage measures on water-prone road sections to avoid stagnant water and waterlogging that will affect the work and life of residents. At the same time, public services are carried out to advise residents to pay attention to travel safety. When the hourly rainfall intensity exceeds 50 mm, more than 30 cm of water will accumulate, which will have a great impact on the passing vehicles and low-lying buildings. The driving vehicles should go to the nearest safe area to avoid parking in low-lying and waterlogging prone areas. In case of serious flooding and other dangerous situations, they should immediately abandon the vehicle to escape. The relevant emergency response departments and rescue units shall closely monitor the disaster situation and do a good job in emergency rescue and relief work for other disasters that may be caused by waterlogging.