Causes of geographical flood disaster in senior high school

The causes of geographical floods in senior high schools are as follows

1, natural reasons:

Characteristics of water system: numerous tributaries (fan-shaped water system and dendritic water system), meandering river (Jingjiang reach), lack of natural river (quasi-river) and low terrain (Haihe River and Pearl River).

Hydrological characteristics: there are many rainstorms in summer, and the river surges.

Climate characteristics: precipitation lasts for a long time and is relatively concentrated (such as rainy weather in the Yangtze River basin). The intensity of summer monsoon change (the second highest intensity: drought in the south, weak waterlogging in the north; The influence of typhoon; El Nino phenomenon, etc.

2. Human factors

Deforestation leads to increased soil erosion and river bed uplift; Reclaiming farmland around the lake, the lake's regulation ability is weak; Unreasonable water conservancy project construction (Weihe River Basin) and other human factors will cause floods.

The harm of flood disaster

Flood disaster will flood farmland, houses, etc., causing a lot of economic losses. Farmland has been destroyed, crops have been reduced or even lost, and raw materials for agricultural products processing industry and light industry are in short supply or raw material costs have increased. It will also cause traffic and communication interruption, block or delay information and traffic.

Water supply facilities and sewage discharge conditions are destroyed, which can cause pollution of well water and tap water sources. After the flood recedes, mosquitoes and flies breed, increasing the possibility of infectious diseases.

Meteorological disaster is one of the important natural disasters in China, and rainstorm and flood disasters are also the main and frequent disasters in meteorological disasters. Therefore, it is very important to master the spatial distribution information of rainstorm and flood disasters. Flood disasters are often sudden and large-scale. Using satellite remote sensing to monitor large-scale floods has a wide field of vision and clear flood boundaries. The introduction of remote sensing information products will make flood disaster monitoring more timely and accurate.