Soil Disintegration Characteristics Around Huangdeng Hydropower Station Reservoir on Lancang River

Abstract

[Objective] Soil disintegration characteristics around the Huangdeng hydropower station reservoir on the Lancang River were studied in order to provide a basis for the prevention and control of soil erosion around the reservoir, reduce the sediment entering the reservoir, and provide a reference for soil and water conservation and ecological restoration in the Three Rivers parallel flow area. [Methods] We used a combination of field survey sampling and laboratory experiments to determine the disintegration rate and physicochemical properties of five typical soils around the reservoir, and to analyze the correlation between soil disintegration rate and soil properties. [Results] Soil disintegration (ranging from strong to weak) was observed to follow the order of red soil, yellow brown soil, siltation soil (top), siltation soil (bottom), and purple soil. Under the saturated soil condition, the ratio of average disintegration rates was 8.76∶5.65∶5.24∶4.29∶1. Soil disintegration was closely related to the soil liquid plastic limit, mechanical composition, porosity, and other properties; There was a significant negative correlation between the average soil disintegration rate and both soil silt and liquid plastic limit. A significant positive correlation was observed between soil disintegration rate and both the content of soil coarse sand and porosity. When the initial moisture content (ω0) was high, soil disintegration rate was significantly negatively correlated with soil organic matter, hydrolytic nitrogen, available phosphorus, and total nitrogen. The linear equations between soil disintegration rate and total nitrogen, silt, and liquid plastic limit for the five soil types in the saturated state had a high fit degree (R2>0.9). [Conclusion] When ω0 was saturated for red soil, yellow brown soil, siltation soil, and purple soil, soil total nitrogen content, silt content, and liquid plastic limit can be used to predict soil disintegration. Forests and grasslands should be established and maintained or engineering measures should be implemented to treat the red soil and yellow brown soil around Huangdeng power station reservoir. Suitable water-zone plants should be planted on siltation soil. Measures should be taken to strengthen the protection of purple soil so that it is suitable for agriculture and forests. Taking these measures will provide more agricultural and forestry land resources for rural revitalization in the reservoir area.

Keywords

• huangdeng hydropower station
• soil around reservoir
• soil disintegration rate
• soil properties
• prevention and control measures