What are the hazards of illegal sand mining?

Affect the safety

of flood control, excessive sand mining in the river channel, resulting in serious downcutting of the riverbed, deep trough forcing the bank, cutting the foot of the torrent, resulting in dangerous sections of the dike; sand mining near the dike, making the thalweg close to the bank, increasing the relative height of the dike body, steepening the bank slope, easily causing the collapse of the dike, endangering the safety of the dike; Sand mining near the levee makes the permeable layer of the levee foundation exposed, resulting in high water level in flood season and the danger of sand turning and water blowing. Sand mining near culvert gates, pumping stations, bank expansion projects and other water conservancy projects seriously threatens the safe operation and flood control functions of these water conservancy projects; The waste slag piles left by sand mining become new river obstacles, which affect the flood discharge and flood control of the river, and easily cause local flood overtopping. In that long-term evolution proces of the river channel

affect the stability

of the river regime, a relatively stable riverbed shape is formed through the interaction between the sediment-carrying flow and the riverbed. Large-scale and disorderly illegal sand mining destroys the riverbed morphology and river regulation works, changes the balance of sediment transport in local reaches, causes local changes in river regime and collapse of shoreline, and brings adverse effects on the stability of river regime in local reaches. If the amount of sand mining is too large, and most of them are in the upstream part of the main river and the beach in the middle of the river, it will cause the riverbed to cut down, change the flow potential of the river and reduce the water level, which will affect the functions of hydrological observation and other engineering facilities, reduce the benefits of the original project, and seriously affect the overall flood control planning and the regional supply, irrigation and drainage system.

Affect the safety

of bridge and navigation Excessive excavation of river sand causes deep riverbed, easy to cause bridge foundation exposed, and even cause bridge collapse; Disorderly excavation of river sand at the internal turmoil of the channel destroys the natural form of the channel, changes the inherent river regime on both sides of the channel, complicates the originally good channel, and ultimately hinders navigation; Sand dredgers miss navigation marks, occupy anchorages, interfere with the normal use of navigation AIDS, and affect the normal maintenance of waterways; sand dredgers occupy waterways, which is prone to sea damage accidents.