The Discharge Outlets Layout Optimization of Typical River Section in the Three Gorges Reservoir Area

2014 ◽  
Vol 955-959 ◽  
pp. 3287-3294
Author(s):  
Zheng Wang ◽  
Ying Liu
Keyword(s):  
Water Quality ◽  
Three Gorges Reservoir ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Mixing Zone ◽  
Unit Load ◽  
Reservoir Area ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
The Impact

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.

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
Keyword(s):  
Soil Erosion ◽  
Three Gorges Reservoir ◽  
Storage Period ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Reservoir Area ◽  
Modis Ndvi ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
The Impact

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.

scholarly journals The Big Data Processing Algorithm for Water Environment Monitoring of the Three Gorges Reservoir Area

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yuanchang Zhong ◽  
Liang Zhang ◽  
Shaojing Xing ◽  
Fachuan Li ◽  
Beili Wan
Keyword(s):  
Water Quality ◽  
Three Gorges Reservoir ◽  
Clustering Algorithm ◽  
Water Environment ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Environment Monitoring ◽  
Reservoir Area ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

Owing to the increase and the complexity of data caused by the uncertain environment, the water environment monitoring system in Three Gorges Reservoir Area faces much pressure in data handling. In order to identify the water quality quickly and effectively, this paper presents a new big data processing algorithm for water quality analysis. The algorithm has adopted a fast fuzzy C-means clustering algorithm to analyze water environment monitoring data. The fast clustering algorithm is based on fuzzy C-means clustering algorithm and hard C-means clustering algorithm. And the result of hard clustering is utilized to guide the initial value of fuzzy clustering. The new clustering algorithm can speed up the rate of convergence. With the analysis of fast clustering, we can identify the quality of water samples. Both the theoretical and simulated results show that the algorithm can quickly and efficiently analyze the water quality in the Three Gorges Reservoir Area, which significantly improves the efficiency of big data processing. What is more, our proposed processing algorithm provides a reliable scientific basis for water pollution control in the Three Gorges Reservoir Area.

scholarly journals Effects of Landscape Positions and Landscape Types on Soil Properties and Chlorophyll Content of Citrus in a Sloping Orchard in the Three Gorges Reservoir Area, China

2021 ◽  
Vol 13 (8) ◽  
pp. 4288
Author(s):  
Siyue Sun ◽  
Guolin Zhang ◽  
Tieguang He ◽  
Shufang Song ◽  
Xingbiao Chu
Keyword(s):  
Soil Properties ◽  
Chlorophyll Content ◽  
Three Gorges Reservoir ◽  
Slope Position ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Reservoir Area ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Landscape Types

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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