The Factors that Influence the Flood Hydrograph

Factors affecting the introduction of the flood process This white paper aims to examine how they affect the flood process, especially in rural and urbanized watersheds in Tokyo. Basin is the area of ​​the surface where the river receives water. The imaginary line can show the edge of the basin basin. This is called the watershed. Other main features of catchment area are shown in the figure. The basin depends on the input water of the atmosphere, and the water goes out of the system through a drain basin and returns to the atmosphere or becomes an input.

Rain gauge is a chart showing how catchment catchment reacts during rainfall. Rainwater levels are important in predicting flood risks and taking precautionary measures necessary to avoid physical damage or loss of human lives. Physical factors are biological factors that affect living things and their surroundings, in which case the surrounding environment is a watershed, so the storm waterway map is affected. These physical factors are basins, size and undulation, type of precipitation, land use and other factors and help to regulate how rivers react to precipitation.

There are various reasons for floods in Vietnam, such as natural factors and human factors. The effects of rain, tide, storm, tropical cyclone are natural factors. Because Vietnam's "annual average precipitation is 1,500 to 2,000 mm" (chinhphu.vn), heavy rain often causes floods in cities where rainwater lines are bad. "The influence of monsoon" (chinhphu.vn) is also the reason why Vietnam must be affected by storms and tropical cyclones. "In 2013, 14 hurricanes, 5 tropical cyclones, and 3 special storms directly entered Vietnam" (Festet), and the heavy rain caused serious floods and caused great damage.

Floods are caused by many factors and are always before the heavy rain. Other causes of floods are moderate to strong wind to water, abnormal highlands, tsunamis caused by submarine earthquakes, dams and dams, damages and failures of protected ponds and lakes, and other water retention infrastructure. Impermeable surfaces and other natural and artificial hazards may hurt the soil, absorb rain vegetation and exacerbate floods. Floods are natural phenomena, but artificially changing land is also a factor. Development will not lead to flooding, but the situation may worsen. In cities and suburbs, roads and roofs prevent rain from being absorbed by the soil. Therefore, there is the possibility of increasing the outflow to lowlands and rainwater drainage system.