Phosphorus critical source areas identification in an agricultural watershed of Three Gorges Reservoir Area, China

2021 ◽  
Author(s):  
Yiwen Zhou ◽  
Zhaoxia Li
Keyword(s):  
Three Gorges Reservoir ◽  
Soil Phosphorus ◽  
Threshold Value ◽  
Point Sources ◽  
Agricultural Watershed ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Critical Source Areas ◽  
Phosphorus Loss ◽  
Source Areas

<p>Agricultural non-point sources (ANPS) pollution are considered to pose risks to water quality in Three Gorges Reservoir Areas (TGRA), especially when those pollution source comes from the hydrologically sensitive areas (HSAs) that generate surface runoff pathways. Therefore, it is necessary to identify the critical source areas (CSAs) or the sensitive regions of pollutants from agricultural lands in order to control and mitigate ANPS pollution effectively. In this study, an improved method integrating the Phosphorus Index (PI) and the Soil Topographic Index (STI) was applied to predict the risk of phosphorus loss and delineate the CSAs of phosphorus in a typical agricultural watershed in TGRA, China. The results showed that using a STI threshold value of 8.5, the HSA was identified 22.08% of watershed areas. The intersection of above two parts account 5.47% of the total watershed, compared with 24.41% of watershed areas based on an existing approach that uses just one criterion. As the results showed , the CSAs of phosphorus loss were mainly located near streams, with high or relatively high soil phosphorus contents or phosphorus fertilizer, or intense soil erosion are observed. The calculated results are in good agreement with the actual situation. Since the approach is based on GIS, and is a relatively simple application uses readily available geospatial data, therefore the technic could be used to improve cost-effectiveness and provide a useful screening tool for water resource managers responsible for identifying and remediating critical NPS source areas. </p>

Phosphorus Loss from Dry Sloping Lands of Three Gorges Reservoir Area, China

Pedosphere ◽  
2013 ◽  
Vol 23 (3) ◽  
pp. 385-394 ◽  
Author(s):  
Zheng-Feng HU ◽  
Ming GAO ◽  
De-Ti XIE ◽  
Zi-Fang WANG
Keyword(s):  
Three Gorges Reservoir ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Phosphorus Loss ◽  
Reservoir Area ◽  
Sloping Lands

Detecting and analyzing soil phosphorus loss associated with critical source areas using a remote sensing approach

2016 ◽  
Vol 573 ◽  
pp. 397-408 ◽  
Author(s):  
Hezhen Lou ◽  
Shengtian Yang ◽  
Changsen Zhao ◽  
Liuhua Shi ◽  
Linna Wu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Soil Phosphorus ◽  
Critical Source Areas ◽  
Phosphorus Loss ◽  
Source Areas

scholarly journals Evaluation of ESV Change under Urban Expansion Based on Ecological Sensitivity: A Case Study of Three Gorges Reservoir Area in China

2021 ◽  
Vol 13 (15) ◽  
pp. 8490
Author(s):  
Hongjie Peng ◽  
Lei Hua ◽  
Xuesong Zhang ◽  
Xuying Yuan ◽  
Jianhao Li
Keyword(s):  
Three Gorges Reservoir ◽  
Urban Expansion ◽  
Urban Land ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Ecological Sensitivity ◽  
Reservoir Area ◽  
Green Development ◽  
Source Data

In recent years, ecosystem service values (ESV) have attracted much attention. However, studies that use ecological sensitivity methods as a basis for predicting future urban expansion and thus analyzing spatial-temporal change of ESV are scarce in the region. In this study, we used the CA-Markov model to predict the 2030 urban expansion under ecological sensitivity in the Three Gorges reservoir area based on multi-source data, estimations of ESV from 2000 to 2018 and predictions of ESV losses from 2018 to 2030. Research results: (i) In the concept of green development, the ecological sensitive zone has been identified in Three Gorges reservoir area; it accounts for about 35.86% of the study area. (ii) It is predicted that the 2030 urban land will reach 211,412.51 ha by overlaying the ecological sensitive zone. (iii) The total ESV of Three Gorges Reservoir area showed an increasing trend from 2000 to 2018 with growth values of about USD 3644.26 million, but the ESVs of 16 districts were decreasing, with Dadukou and Jiangbei having the highest reductions. (iv) New urban land increases by 80,026.02 ha from 2018 to 2030. The overall ESV losses are about USD 268.75 million. Jiulongpo, Banan and Shapingba had the highest ESV losses.

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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