Advantages and disadvantages of building reservoirs in high school geography.

Main functions: flood control and drought relief/flood control and drought relief (the most important), and secondary functions of power generation: irrigation, water supply, shipping,

fishery

Travel.

Disadvantages of building reservoirs

1, increase the frequency of geological disasters in the reservoir area and its impact. The construction of the reservoir may induce earthquakes and increase the earthquake frequency in the reservoir area and nearby areas.

2. Sediment deposition. Due to sediment deposition in the reservoir area, the actual water storage capacity of the reservoir is decreasing.

3. Soil salinization of downstream land. Continuous irrigation makes the groundwater level rise and brings the salt in deep soil to the surface. The high content of salt and various chemical residues in irrigation water lead to soil salinization.

.4. The water quality in the reservoir area and downstream has deteriorated. The water surface area of the reservoir area is large, a large amount of water evaporates, and soil salinization increases the salt and chemical residues in the soil, thus polluting groundwater and increasing the salt content of the downstream rivers.

5. Impact on downstream rivers

Due to the change of water potential and sediment concentration, it may also change the flow direction and alluvial degree of the downstream rivers, resulting in serious erosion of the river bed and the retreat of the river (sea) mouth to the land direction.

6. Immigration and its influence on scenic spots and historic sites in the reservoir area. Because the reservoir area is flooded by the rising water level, it is a big problem to emigrate. Moreover, because the scenic spots and cultural relics in the reservoir area have been submerged by the construction of the reservoir area, they need to be relocated and restored.

7. Impact on the spread of diseases Due to the static water flow, the incidence of schistosomiasis and other epidemics in the downstream will increase, and mosquitoes, flies and other pathogenic microorganisms will be more likely to breed in the reservoir area.

8. Impact on Climate After water storage in the reservoir area, the water area is enlarged and the water evaporation is increased, which reduces the temperature difference between day and night in the nearby area and changes the climate environment in the reservoir area.