scholarly journals Evaluation of Water Resources Vulnerability in the Coastal Areas of the Yellow Sea and Bohai Sea under Seawater Intrusion——A case study of Longkou City, Shandong Province

2021 ◽  
Vol 299 ◽  
pp. 01012
Author(s):  
Lei Qiu ◽  
Ying Cao ◽  
Jingyi Huang

In view of the increased vulnerability of water resources system caused by seawater intrusion in the coastal areas of the Yellow Sea and Bohai Sea, this paper based on the VSD(Vulnerability Scoping Diagram) model to construct the water resource vulnerability evaluation index system of “exposure-sensitivity-adaptive capacity” under seawater intrusion. Then use entropy-TOPSIS method to evaluate water resource vulnerability and divide the levels. In addition, take Longkou City of Shandong Province as an example to conduct empirical research. The results show that the water resource vulnerability of Longkou City is at a strong vulnerability level. The water resources system is under obvious pressure. Population density, per capita GDP, temperature and precipitation change are the main factors of the system pressure. Seawater intrusion has a high degree of impact on water resources vulnerability and water resource system is more sensitive to groundwater level, chloride concentration and other stimuli. The improvement of water use efficiency and scientific and technological investment contribute to the significant enhancement of the adaptability of the water resources system of Longkou City.

2018 ◽  
Vol 10 (11) ◽  
pp. 4158 ◽  
Author(s):  
Lei Qiu ◽  
Jingyi Huang ◽  
Wenjuan Niu

Seawater intrusion has occurred in the coastal area of the Yellow Sea and the Bohai Sea as early as the 1970s, and the situation is worsening, with rapid socioeconomic development in recent years. Substantial amounts of groundwater have been exploited to support socioeconomic activities, especially agricultural activities, causing a reduction in the groundwater level, and hence the intrusion of seawater. This issue seriously restricts the sustainable socioeconomic development of these coastal areas. To this end, this paper applied the improved Tapio decoupling theory to analyze the degree of decoupling, and the spatial difference between the economic growth and the groundwater consumption of the five provinces and cities in the coastal areas of the Yellow Sea and Bohai Sea in the period of 2003–2016. Based on the improved STIRPAT (Stochastic Impacts by Regression on Population, Affluence, and Technology) model and panel data, we determined the driving factors of groundwater consumption in the coastal areas of the Yellow Sea and Bohai Sea. The results demonstrated that the effective irrigation area of farmland should be expanded, new water-saving technology should be introduced, the crop planting structure should be readjusted, and the consumption of groundwater should be reduced. By implementing these measures, it would be possible to contain seawater intrusion in the coastal areas of the Yellow Sea and Bohai Sea.


2019 ◽  
Vol 16 (22) ◽  
pp. 4485-4496 ◽  
Author(s):  
Ye Tian ◽  
Chao Xue ◽  
Chun-Ying Liu ◽  
Gui-Peng Yang ◽  
Pei-Feng Li ◽  
...  

Abstract. Nitric oxide (NO) is a short-lived compound of the marine nitrogen cycle; however, our knowledge about its oceanic distribution and turnover is rudimentary. Here we present the measurements of dissolved NO in the surface and bottom layers at 75 stations in the Bohai Sea (BS) and the Yellow Sea (YS) in June 2011. Moreover, NO photoproduction rates were determined at 27 stations in both seas. The NO concentrations in the surface and bottom layers were highly variable and ranged from below the limit of detection (i.e., 32 pmol L−1) to 616 pmol L−1 in the surface layer and 482 pmol L−1 in the bottom layer. There was no significant difference (p>0.05) between the mean NO concentrations in the surface (186±108 pmol L−1) and bottom (174±123 pmol L−1) layers. A decreasing trend of NO in bottom-layer concentrations with salinity indicates a NO input by submarine groundwater discharge. NO in the surface layer was supersaturated at all stations during both day and night and therefore the BS and YS were a persistent source of NO to the atmosphere at the time of our measurements. The average flux was about 4.5×10-16 mol cm−2 s−1 and the flux showed significant positive relationship with the wind speed. The accumulation of NO during daytime was a result of photochemical production, and photoproduction rates were correlated to illuminance. The persistent nighttime NO supersaturation pointed to an unidentified NO dark production. NO sea-to-air flux densities were much lower than the NO photoproduction rates. Therefore, we conclude that the bulk of the NO produced in the mixed layer was rapidly consumed before its release to the atmosphere.


2019 ◽  
Vol 58 (4) ◽  
pp. 903-917 ◽  
Author(s):  
Manman Ma ◽  
Yu Zhen ◽  
Tiezhu Mi

AbstractStudies of the community structures of bacteria in marine aerosols of different particle sizes have not been reported. Aerosol samples were collected using a six-stage bioaerosol sampler over the Bohai Sea, the Yellow Sea, and northwestern Pacific Ocean in the spring of 2014. The diversity and composition of these samples were investigated by Illumina high-throughput sequencing, and 130 genera were detected in all of the samples; the most abundant bacterial genus was Bacteroides, followed by Prevotella and Megamonas. The Chao1 and Shannon diversity indices ranged from 193 to 1044 and from 5.44 to 8.33, respectively. The bacterial community structure in coarse particles (diameter larger than 2.1 μm) was more complex and diverse than that in fine particles (diameter less than 2.1 μm) in marine bioaerosols from over the Yellow Sea and northwestern Pacific Ocean, while the opposite trend was observed for samples collected over the Bohai Sea. Although we were sampling over marine regions, the sources of the bioaerosols were mostly continental. Temperature and wind speed significantly influenced the bacterial communities in marine aerosols of different particle sizes. There may be a bacterial background in the atmosphere in the form of several dominant taxa, and the bacterial communities are likely mixed constantly during transmission.


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