Soil erosion in the Three Gorges Reservoir area

Soil Research ◽  
2011 ◽  
Vol 49 (3) ◽  
pp. 212 ◽  
Author(s):  
Xibao Xu ◽  
Yan Tan ◽  
Guishan Yang ◽  
Hengpeng Li ◽  
Weizhong Su

Spatial and temporal change in soil erosion in the Three Gorges Reservoir area since the water storage of the reservoir began filling to 135 m in 2003 is poorly understood. Using a modified soil erosion model, this study quantifies and analyses change in the extent and intensity of soil erosion in the region from 2000 to 2008. MODIS-NDVI remote sensing data (with 250 m spatial resolution) are used in the modelling and analysis of the study. The total amount, area, and intensity of soil erosion in the reservoir region presented a declining trend from 2000 to 2008. Yet there was an anomaly in the trend, in which extreme soil erosion occurred in 2003 and lasted until 2005. The average volume of soil erosion per year decreased by 4.10 × 106 t and the mean area of land experiencing soil erosion reduced by 1129.6 km2 from the pre-storage period (2000–02) to post-storage period II (2006–08). Land suffering soil erosion at high, very high, and severe levels mainly comprises forest and cropland on slopes with gradients ≥15° and is largely distributed in the eastern and south-western sections of the reservoir area. Land experiencing soil erosion at slight or moderate levels mainly involves cropland and forest on slopes with gradients ≥10° in the central section of the reservoir area. The impact of the Three Gorges Project on soil erosion since 2000 has been mainly mediated through three mechanisms: near-resettlement of rural and urban people; increased frequency and severity of geological hazards induced by rising storage of the reservoir; and implementation of ecological projects in the region. Through the former two mechanisms, soil erosion in the affected communities has been exacerbated, while the ongoing ecological projects appear to offset both the extent and intensity of soil erosion in the reservoir region. Other important factors influencing soil erosion include urban reconstruction and expansion, varying intensity of precipitation, and soil degradation.

2014 ◽  
Vol 955-959 ◽  
pp. 3287-3294
Author(s):  
Zheng Wang ◽  
Ying Liu

To improve water quality and alleviate pollution in Changshou-Fuling section of the Three Gorges Reservoir Area, an analysis methodology of regional key discharge outlet based on hydrodynamic-water quality model was developed. The EFDC model was used to study the impact of different discharge outlets on the transport of contamination in the study area by using the concept of pollutant mixing zone and pollutant mixing zone per unit load. Model calibration was conducted using observed data in 2008. Results indicated that EFDC could perfectly simulate hydrodynamics characteristics and contaminant transport process. Calculated results of pollutant mixing zone per unit load showed that the discharge outlet location in Fuling is more reasonable than that in Changshou. This study provides useful information for optimization of discharge outlets location and prediction of pollutant mixing zone in the study area, which is important for the government to make water pollution control measures.


2021 ◽  
Vol 272 ◽  
pp. 01007
Author(s):  
Xi He

The Three Gorges Reservoir Area is an important ecological barrier and an important area of water conservation in China. Due to natural and man-made factors, the regional urbanization process is accompanied by soil erosion. In recent years, by actively implementing measures such as tree planting and afforestation, water and soil conservation projects, the forest coverage rate in the Chongqing Three Gorges Reservoir area has increased significantly, and soil erosion has been initially controlled. But the task of environmental protection in the Three Gorges Reservoir area is still arduous. This research analyzed the causes of soil erosion caused by the urban process, by collected and combed the data of soil erosion in the Three Gorges Reservoir area of Chongqing over the years. The causes of soil erosion in the Three Gorges Reservoir area caused by the urbanization process were deeply analyzed, we proposed to improve legislation and supervision; strengthen publicity and education of soil and water conservation; adopt new technology and technology and other governance countermeasures. The Three Gorges Reservoir is an important ecological barrier in the upper reaches of the Yangtze River. The control of soil erosion in the area has important ecological and social benefits for protecting the ecological environment of the Yangtze River Basin in China.


2019 ◽  
Vol 697 ◽  
pp. 134164 ◽  
Author(s):  
Mingjun Teng ◽  
Chunbo Huang ◽  
Pengcheng Wang ◽  
Lixiong Zeng ◽  
Zhixiang Zhou ◽  
...  

2021 ◽  
Vol 13 (8) ◽  
pp. 4288
Author(s):  
Siyue Sun ◽  
Guolin Zhang ◽  
Tieguang He ◽  
Shufang Song ◽  
Xingbiao Chu

In recent years, soil degradation and decreasing orchard productivity in the sloping orchards of the Three Gorges Reservoir Area of China have received considerable attention both inside and outside the country. More studies pay attention to the effects of topography on soil property changes, but less research is conducted from the landscape. Therefore, understanding the effects of landscape positions and landscape types on soil properties and chlorophyll content of citrus in a sloping orchard is of great significance in this area. Our results showed that landscape positions and types had a significant effect on the soil properties and chlorophyll content of citrus. The lowest soil nutrient content was detected in the upper slope position and sloping land, while the highest exists at the footslope and terraces. The chlorophyll content of citrus in the middle and upper landscape position was significantly higher than the footslope. The redundancy analysis showed that the first two ordination axes together accounted for 81.32% of the total variation, which could be explained by the changes of soil total nitrogen, total phosphorus, total potassium, available nitrogen, available potassium, organic matter, pH, and chlorophyll content of the citrus. Overall, this study indicates the significant influence of landscape positions and types on soil properties and chlorophyll content of citrus. Further, this study provides a reference for the determination of targeted land management measures and orchard landscape design so that the soil quality and orchard yield can be improved, and finally, the sustainable development of agriculture and ecology can be realized.


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