Spatial-temporal variation of permanganate index under accident conditions during different water periods in Zigui drinking water source area, Three Gorges reservoir area, China

2019 ◽  
Vol 101 ◽  
pp. 647-660 ◽  
Author(s):  
Xiaowen Ding ◽  
Xu Han ◽  
Bo Kang ◽  
Aifeng Zhai
2019 ◽  
Vol 11 (24) ◽  
pp. 7074
Author(s):  
Xiaoling Tang ◽  
Aifeng Zhai ◽  
Xiaowen Ding ◽  
Qiande Zhu

With China’s rapid economic growth and increasing speed of urbanization, water pollution accidents have become one kind of environmental pollution source in China and bring potential risk to urban drinking water safety. The Huangjuedu Drinking Water Source Area is an important water source in Chongqing City (Southwest China) and a water intake source for the Jiangnan Waterworks of the Chongqing Drinking Water Company. There are still risks of water pollution accidents caused by ship leakage, road traffic accidents, chemical plant leakage, etc. The safety of the drinking water area is related to regional residents’ health and life safety and also has a profound impact on economy development and social stability. To reduce the harmful impacts of water pollution, it is of great scientific value and practical significance to analyze the pollutant diffusion of water pollution accidents with the Three Gorges Reservoir Area drinking water source security platform. In this paper, a two-dimensional water quality monitoring model was applied, and the digital elevation model was incorporated into the geographic information system, which generated a computational grid. Then, the Three Gorges Reservoir Area drinking water source security platform was developed. The platform can predict the water flow velocity, pollutant concentration at the drinking water inlet, and the spatial and temporal distribution of pollutants in the whole water source area. Furthermore, a hypothetical ammonia nitrogen leak accident was analyzed using this safety platform. The ammonia nitrogen concentration at the intake of the drinking water source area was detected and analyzed by the security platform from the time of the accident until the concentration dropped to the background during four water periods under different wind direction conditions. The pollutants took 19, 22, 25, and 40 min to reach the water quality standard during the four water periods. Moreover, the diffusion of ammonia nitrogen in the southeast wind was faster than that in the southwest wind. The results showed that the platform is scientific and practical, and the prediction results are helpful for the Emergency Management Department to quickly and accurately predict the migration of ammonia nitrogen pollution and make corresponding plans under accident conditions.


2021 ◽  
Vol 13 (15) ◽  
pp. 8490
Author(s):  
Hongjie Peng ◽  
Lei Hua ◽  
Xuesong Zhang ◽  
Xuying Yuan ◽  
Jianhao Li

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.


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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