Method for prevention and control of super large-scale floods and debris flows

A method for the prevention of floods having a total discharge volume of more than 100×104 m3 or a peak flow of more than 2000 m3/s and debris flows, comprising:

• determining a planning and design standards of an engineered prevention system in a basin, and a design protection level and standards of a key project according to protection standards of downstream objects;
• obtaining a basin topography according to investigation and measurements of historical disasters in the basin;
• calculating the peak discharge or a total debris flow volume based on field investigations of historical flood traces or hydrological calculations of small watersheds;
• and estimating source materials of debris flows through a field investigation of distribution of materials in the basin;
• when considering potential debris flows in the basin, arranging artificial structures or artificial structure arrays to control an initial amount of source materials, such that the artificial structures protects a bed incision by flows and increases flow friction, which contributes to regulating energy consumption;
• if a flood erupts in the basin under a certain design standard, using a combination of the drainage channel, check dam, and retaining basin to regulate the floods and debris flows;
• if a flood erupts in the basin under a certain design standard, using field investigations and sampling tests to determine locations and quantity of key projects in the basin;
• wherein key control dams are placed every 3-5 common check dams, and a storage capacity of a control dam is equal to or greater than a total storage capacity of its upstream common check dams, such that the control dam retains sediments that come from upstream check dams when upstream check dams break out;
• dividing the key control dams into four regions comprising:
• region A, a foundation of a dam body;
• region B, a left shoulder of the dam body;
• region C, a right shoulder of the dam body;
• and region D, a discharge outlet and overtopping weir;
• wherein the four regions are designed based on different protection standards;
• wherein the regions A, B, and C are designed according to a same standard, and a pile foundation is used to reinforce the foundation of the dam body;
• wherein a design standard of region D is lower than that of the other three regions;
• wherein region D is allowed to break when encountering floods and debris flows, while the regions A, B, and C are not allowed to burst.