The pros and cons of building a reservoir.

Main functions: flood control and drought relief/flood control and drought relief (most important), power generation. Secondary functions: irrigatio

The pros and cons of building a reservoir.

Main functions: flood control and drought relief/flood control and drought relief (most important), power generation. Secondary functions: irrigation, water supply, shipping, fishery, tourism.

. Disadvantages of building reservoirs

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

2. Sedimentation. Mud in the reservoir area Sand siltation has caused the actual storage capacity of the reservoir to continue to decrease

3. The soil in the downstream land is salinized. Continuous irrigation also causes the groundwater level to rise, bringing the salt in the deep soil to the surface, plus the irrigation water The high content of salt and various chemical residues has led to soil salinization

.4. Deterioration of water quality in the reservoir area and downstream Chemicalization increases the salt content and chemical residues in the soil, thereby polluting the groundwater and increasing the salinity content of the downstream river water.

5. Impact on the downstream river channel Due to changes in water potential and sediment content, It may also change the river flow and alluvial degree in the downstream reaches, causing the river bed to be severely eroded and the river (sea) mouth to retreat toward the land.

6. Immigration issues and the impact on the scenery and cultural relics of the reservoir area The impact is that the reservoir area will be submerged due to rising water levels, requiring resettlement (a big problem). And due to the construction of the reservoir, the scenic spots and cultural relics in the reservoir area will be submerged, requiring relocation, restoration, etc.

7. Impact on the spread of disease Due to the static flow of water, the incidence of schistosomiasis and other epidemic diseases in the lower reaches will increase, and the reservoir area will also be more likely to breed mosquitoes, flies and other pathogenic microorganisms. 8. Impact on climate After the reservoir area is impounded, the water area will increase. Expanding, the evaporation of water will increase, which will cause the temperature difference between day and night in nearby areas to shrink, changing the climate environment of the reservoir area.