In the environmental environment, urban storms and disaster defense countermeasures and suggestions

On July 20, 2021, a heavy rain occurred in Zhengzhou, Henan, and broke through historical records in strength and scope, far exceeding the urban rural flood prevention and drainage capacity, leading to disaster complications such as waterlogging, rivers, floods, and landslides. Special natural disaster. In the context of global climate change leading to frequent extreme weather, urban storms and floods are increasingly increasing. We must look at the whole country, plan the future, and deeply understand the significant impact of climate change and rapid urbanization on the prevention and control of urban flood disasters. The mechanism of the development of the disaster chain, reasonably formulate, implement urban construction and flood prevention planning, scientifically carry out the management and response of disaster prevention and mitigation, comprehensively improve the ability of urban defense to prevent storms and floods, and strive to encounter the people's lives when the people's life is over rainstorm. There are protection, no paralysis in cities, and less loss of national economy.

Improve the awareness of risk risk in urban flood disasters in the environmental environment

Climate change has significant impact

Studies have shown that under the condition of climate change in the future, the number of heavy rain days and precipitation intensity in most areas in my country will increase. Even under the premise of the "Paris Agreement" at 1.5 ° C ideal goal, the East Asian monsoon still has an enhanced trend. Weather conditions such as the Western Pacific tropical cyclone and the north of the Western Pacific subtly high pressure will increase. The probability of heavy rain will still increase.

Urban Yu Island effect cannot be ignored

my country's urbanization achievements are remarkable, and the scale of urban areas in large cities has continued to expand, and 6 cities with an area of ​​more than 1,000 square kilometers have reached 6. The urban heat island effect affects the structure of the atmospheric boundary, increased surface resistance in high -rise buildings in the urban area, and the discharge of urban particulate matter provides condensate tuberculosis for rainfall. The three factors have significantly impact the climate and rainfall conditions in the urban area. Under the action, the urban rainfall is more concentrated, and the "rain island" effect is significant.

With the significant impact of climate change and the urban rain island effect cannot be ignored, the consistency of the meteorological hydrological sequence before and after urbanization is damaged. Frequent rainstorm appears. The absolute ability of the flood prevention and drainage projects of historical data design and construction is unchanged, but the probability of failure has increased relative to the design goals.

The form of urban floods is complicated and diverse

The flood disasters encountered in the local and larger regions are mainly divided into three categories: cities are adjacent to rivers floods, waterlogging in the urban area, suburban floods and geological disasters. The secondary disasters may be more complicated.

The scale and influence of rivers and rivers are huge, and it is still the primary form of flood disasters. There are many cities at all levels in my country that are distributed along the river and flood prevention. The embankment standards of medium and above cities are generally more than 100 years old, and the key flood control cities are in 200 years. Under the conditions of climate change and some rivers due to the decreased flooding ability of the river, the "black swan" incident that the city encounters the flood disaster in the city must be ahead of the rivers and crowded flooding capacity.

The waterlogging in the urban area is caused by the stagnation, seepage, storage, and exclusion of local heavy rain in the urban area, and is a flood that occurs within the city. Urban ground hardening increases the runoff coefficient and accelerates the speed of convergence. The water storage space and river drainage space of the water are insufficient. main reason.

There are many mountains in the suburbs of urban, and some cities are built according to mountains. Extraordinary rainstorms in mountainous areas can easily cause geological disasters such as floods and landslides, landslides, mudslides. Such disasters have strong local area, violent processes, and difficult to prevent engineering prevention and forecasting and early warning. Surgery. The suburbs are still within the scope of urban administrative management and should be considered in the defense of urban heavy rain disaster.

The process of urbanization is developing rapidly, frequent disasters and severe losses

According to the "City Construction Statistics of 2020", my country has 86 large cities with a population of more than one million in the urban area; according to the latest data of the seventh national census, there are 21 large and large cities with a population of more than 5 million in my country's urban area. The rapid growth of urban bases and scale is the main cause of frequent causes of prevention and floods in my country's cities and major losses.

The "Technical Specifications for Urban Waterwatering Prevention and Control" (GB512222-2017) stipulates the design reproduction period for urban waterlogging prevention and control: a big city 30-50 years, one encounters in 50-100 years, and 100 years in the large city. The maximum value and sun rainfall are generally adopted.

Although the climate conditions in various parts of my country are different, because cities have determined different heavy rainfall values ​​based on their own meteorological data, it can be uniformly estimated that my country's cities have encountered an frequency of overwhelming rainfall. With the design of urban waterlogging prevention and control period, representing the total level of the urban defense of different forms of heavy rain and flood disasters, assuming that the large cities are set up in accordance with the standard in 50 years, then there are nearly 2 large cities in my country that encounter super rainstorms in nearly 2 big cities each year; assuming Both the large and large cities have set up defense in accordance with the standard in 100 years, and there will be an an average of once every five years in my country. Therefore, it can be found that the urban heavy rain and flood disaster can be faced by a major issue that urban storms and flooding disasters must face, and they must increase their awareness of risk of urban flood disasters.

Dynamic revision and planning and accelerating the construction of the engineering system for urban defense flood disasters

Improve the connotation of "setting the city with the water", and the planning plan with rigid constraints

Improve the connotation of "setting the city with water", which not only regards water resources as a rigid constraint for determining the scale of urban development, but also defense floods as a rigid constraint for determining urban construction space planning. In the urban planning, consider the seepage, storage, and exhaust space of urban rainfall in order to prevent the rigid constraints of disasters, reserved and allowed the natural rain and flood channels, dehuman destruction space to avoid people's struggle. Improve the standards, coordinate multi -regulations, make up for the shortcomings of planning

Fully attach great importance to the problems of urban development invasion of flood storage flood space, fragile water in urban lifeline, improve the standards, specifications, and planning in different fields, coordinate the planning goals of land space, flood defense, municipal transportation, sponge city, river landscape and other planning goals, and coordinate different levels of different levels The ecological value, resource utilization, flood storage and other comprehensive goals of rainfall. Comprehensive consideration of rivers and rivers flood defense, urban waterlogging and drainage, and urban flood prevention and control, for the surrender of heavy rainstorm, study and formulate different types of flood disaster risks in different types of flood disaster risks. In the specific planning, consider the impact of climate change and urbanization, supplement the new data to re -calculate the frequency curve of urban rainstorms, review urban flood prevention and drainage standards, make up for debt, and enhance the toughness of the city.

Leave enough space, enhance standards, and storage combination to ensure flooding and drainage capabilities

The urban or cross -city traffic main lines and urban rivers and urban rivers, large and low -lying areas, etc. are the main risk areas for cities to facing over rainstorms. Urban construction should optimize the space storage space and flood drainage channels, strengthen the stagnation and drainage capacity of the main risk areas, and improve the reform of standards, such as the construction of the surface or underground flood stagnation space, and the construction of deep tunnels. For weak links such as self -discharge and water top support, to ensure that the drainage capacity has reached anti -defense standards, and it is working normally when it encounters super rainstorming. For the situation of the urban area and the urban boundary, to ensure that the out -of -the -way flood discharge channels are "unobstructed" in accordance with the design standards, and are not affected by the border of administrative management.

Pay attention to the safety of water conservancy project around the city

Water conservancy projects such as the upstream water supply reservoir and downstream regulating reservoir are an important infrastructure required for urban flood prevention, water resource utilization, and ecological landscapes. disaster. It is necessary to attach great importance to the safety of water conservancy projects around the city and carry out safety assessment; strengthen dispatch management, strictly implement the scheduling rules, and reduce the pressure of dams; strengthen safety monitoring and dangerous inspections, discover problems in time; strengthen water conditions monitoring and forecast, in the prerequisite for ensuring safety Strengthen the use of rain and flood resources to prevent concentrated water abandoned and heavy rain superimposed; strictly prevent damage under extreme circumstances and exacerbate downstream disasters.

Strengthen the investigation of hidden dangers of various types of projects in cities

Carry out the investigation of hidden safety hazards of urban infrastructure and lifestyle projects such as municipal, transportation, transportation, power, gas, gas, logistics, education, medical care, and sports. Floods are easy to cause disasters in underground space and low -lying areas of the dense population, concentrated equipment. To this end, special facilities and emergency plans for emergency avoidance and escape should be set up. Engineering measures should be set up to ensure the safety of important underground space and underground lifeline.

Scientifically improve the level of disaster prevention and mitigation and emergency management

Accurate forecast, precise early warning

Accurate weather forecast is the prerequisite for issuing precision disaster prevention warnings. At present, meteorological monitoring and forecasting capabilities still do not fully meet the needs of urban heavy rainstorm disaster defense. The forecasting area, time, and strong rain are not accurate, and it has not yet reached the level of space to the neighborhood, time to hours. We should continue to strengthen basic research and technological development to improve accuracy of disaster weather forecasting.

Clarify the nature and role of disaster weather forecast and flood disaster warning to ensure the accuracy and timeliness of disaster warning. Study and improve the key indicators and monitoring systems of urban storms and waterlogging warnings. Different cities in the south and north have set up the operating flood disaster warning threshold indicators such as measured rainfall, river water levels, and water stagnation in the urban area, and are included in the disaster prevention and emergency command system.

Clarify your responsibilities, linkage response

Strengthen the risk awareness and bottom line of leading cadres, implement the main responsibilities of flood prevention and disaster relief at all levels and specific responsibilities of various functional departments, strictly implement the disaster prevention command system and decision -making process, clarify the emergency management responsibilities and linkage mechanisms of urban flood defense, and strengthen Information release and organizational mobilization capabilities.

Effectively implement the "big emergency" concept, study the coupling mechanism of meteorological forecasting and disaster risk early warning, and study the efficient and rapid emergency response linkage mechanism from government organizations and functional departments to emergency linkage linkages of enterprise operating units, and actively responding to the public in the public. The high -efficiency coordinated decision -making and implementation mechanisms of heavy rain and flood disasters have enhanced urban flood defense and emergency rescue capabilities.

Smart disaster prevention, people -oriented

Improve the informatization and intelligence level of urban flood disasters monitoring and early warning, fully consider the exposure of people in the disaster environment, combine accurate positioning, emergency communication and big data technologies, people -oriented, and individuals exposed to individuals exposed to specific time -space disaster risks. The group issues customized early warning information through mobile phone emergency warning notifications and other methods to provide targeted action guidelines.

Know the risk and strengthen the community

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