scholarly journals Principle and Model Block Diagrams of Cd Content Monthly Variation in Surface and Bottom Waters in Central Bay

2021 ◽  
Vol 236 ◽  
pp. 03019
Author(s):  
Dongfang Yang ◽  
Dong Yang ◽  
Weifeng Ling ◽  
Dong Lin ◽  
Haixia Li
Keyword(s):  
Surface Water ◽  
Water Body ◽  
Bottom Water ◽  
Jiaozhou Bay ◽  
Variation Principle ◽  
Monthly Variation ◽  
Model Block ◽  
Sea Current ◽  
Bottom Waters ◽  
Monthly Changes

According to survey data, in Jiaozhou Bay in 1992, the vertical distribution of Cd content and monthly changes in the surface and the bottom of the central sea area of Jiaozhou Bay were studied, and monthly changes, migration processes and variational principles of the Cd content in surface and bottom water were determined. In May, August, and October, the water body that the main sea current did not pass through were those in the center of the bay. Cd content in central surface water of Jiaozhou Bay was not transported from any source outside the bay from May to October. The results showed that Cd content transported by the main sea current changed from low to high in October, May and August; Cd content transported by the bay current changed from low to high: October, August and May; Cd content in surface water in the bay center changed from low to high in: August, May and October; Cd content in the bottom bay center changed from low to high in May, October and August. Thus, from May to October, monthly changes in these four parts were different. For this reason, the monthly variation principle of Cd content in the surface and bottom waters of the bay was proposed. In addition, the model block diagrams were established to show the change process and principle of Cd content deposition and migration. The principle shows that the bay current has no direct effect on the surface water in the center of the bay from May to October. However, the bottom water body in the center of Jiaozhou Bay was greatly affected, and the surface water body in the center of Jiaozhou Bay was further affected by the upwelling.

scholarly journals Transfer Mechanism and Change Process of Matter Content in Jiaozhou Bay

2021 ◽  
Vol 245 ◽  
pp. 02030
Author(s):  
Dongfang Yang ◽  
Haixia Li ◽  
Dong Lin ◽  
Weifeng Ling ◽  
Hong Zhu
Keyword(s):  
Surface Water ◽  
Change Process ◽  
Bottom Water ◽  
Jiaozhou Bay ◽  
Matter Content ◽  
Transfer Mechanism ◽  
Ocean Current ◽  
Deep Channel ◽  
Sea Current ◽  
Bottom Waters

Based on the survey data of Jiaozhou Bay in 1992, the changes of Pb content in the surface and bottom waters affected by the ocean current in the process of transportation in Jiaozhou Bay were studied, and the sedimentation process and mechanism of Pb content in the surface and bottom waters were determined. The time change process of sedimentation shows that: from May to October, 1) the Pb content transported by the ocean current from the main sea decided the Pb content change in the bottom water; 2) in August, under the carrying of a large number of plankton and suspended particulate matter, the Pb content transported by the ocean current and that in the surface and bottom water reached the maximum value in a year. According to the spatial change process of subsidence, the results show that in August and October, the inlet of the “Cangkou Channel”, the outlet of the “Former Reef Channel” and the deep channel of the strait on the side of Xuejia Island all revealed narrower channel, accelerated current, and deep erosion, forming a deep channel. In such waters, a large amount of Pb content was deposited. On the basis of the sedimentation process in the center of the bay, the outer sea current carried a high content of Pb to surround the nearshore waters in the bay. In May, the main sea current did not affect the surface water in the center of Jiaozhou Bay, nor did it affect the bottom water in the center of Jiaozhou Bay. From May to October, the ocean current didn’t affect the surface water in the center of Jiaozhou Bay, either, but it has brought a huge impact on the bottom water in the center of Jiaozhou Bay. In the transfer process of Pb content in the water body in the center of the bay, the authors put forward the transfer mechanism of the matter content in Jiaozhou Bay, and establish the block diagram of the modelwhich demonstrates the mechanism and the change process of the matter content transfer.

scholarly journals Changing Degree Model of Pb Content Transported by Ocean Currents

2021 ◽  
Vol 236 ◽  
pp. 03012
Author(s):  
Dongfang Yang ◽  
Dong Lin ◽  
Yuan Zhang ◽  
Xianpeng Yuan ◽  
Haixia Li
Keyword(s):  
Surface Water ◽  
Bottom Water ◽  
Block Diagram ◽  
Jiaozhou Bay ◽  
Deposition Process ◽  
Ocean Currents ◽  
Change Mechanism ◽  
Sea Current ◽  
Bottom Waters ◽  
Sea Currents

Based on the survey data of the waters of Jiaozhou Bay in May, August and October 1992, the change of Pb content and its deposition process in the surface and bottom waters of Jiaozhou Bay were studied. According to the definition and model of Dongfang Yang’s content changing degree, the variation of Pb content at surface and bottom and of Pb content transported by main sea current formed a peak line in the southeast waters of Jiaozhou Bay. The Pb content on the surface reached its peak in August. From May to August, Dongfang Yang’s content changing degree was 79.84°. However, from August to October, it was -85.29°. Specifically, in surface water, Dongfang Yang’s content changing degree from May to August was 62.48°. From August to October, Dongfang Yang’s content changing degree was -39.00°. In the bottom water, Dongfang Yang’s content changing degree from May to August was 70.41°. From August to October, Dongfang Yang’s content changing degree was -80.03°. It indicates that the change of Pb content in surface nearshore waters passed through by the main sea current was determined by the change of Pb content transported by the current. The change of Pb content in surface seawater through the change of ocean currents increases or decreases the increase or decrease of Pb content in surface water —The Pb content of surface water increased or decreased with the increase or decrease of Pb content transported by main sea currents. The Pb content temporal variation in the surface and bottom of the southeastern waters of Jiaozhou Bay from May to October reveals the Pb content settling law: With the increase of Pb content in surface water, the Pb content in bottom water rose faster than that in surface water. When the Pb content in surface water decreased, the Pb content in bottom water decreased much faster than that in surface water. Therefore, the change mechanism of surface and bottom water caused by source transport is proposed with the corresponding model block diagram and changing degree model of Pb content transported by ocean currents.

scholarly journals The influence of the Pb Content of Source Transport on its Distribution in the Bottom Layer

2020 ◽  
Vol 185 ◽  
pp. 02017
Author(s):  
Dongfang Yang ◽  
Dong Yang ◽  
Weifeng Ling ◽  
Dong Lin ◽  
Haixia Li
Keyword(s):  
Water Quality ◽  
Surface Layer ◽  
Water Body ◽  
Jiaozhou Bay ◽  
Bottom Layer ◽  
Horizontal Distribution ◽  
Ocean Current ◽  
Open Sea ◽  
Sea Current ◽  
Bottom Waters

Based on the survey data of Jiaozhou Bay in 1992, the vertical distribution and seasonal variation of Pb in the surface and bottom waters from the bay center to the south of the bay mouth were studied, and the seasonal distribution, range and horizontal distribution trend of Pb content in the surface and bottom waters were determined. The results show that in May, August and October, Pb content in the waters from the south of the bay mouth to the center of the bay, and in the whole water body from the surface to the bottom, ranged from 4.20 to 24.39 μg/L, which met the national sea water quality standard of class II, class III and class IV. In other words, water quality was mildly, moderately and severely polluted by Pb. In the surface and bottom water, the Pb content was from low to high in May, October and August; In addition, the seasonal change of Pb content in the water body from low to high was as follows: spring, autumn and summer. In May, August and October, when the content of Pb in the surface layer was high, the corresponding bottom layer was high. And when the content of Pb in the surface layer was relatively high, and the corresponding bottom layer was relatively high. It shows that in May, August and October, the loss of Pb content from the surface layer to the bottom layer was relatively large. Further, in the waters from the southeast to the center, in May and August, the horizontal distribution trend of Pb in the surface layer was opposite to that in the bottom layer. But in October, the horizontal distribution trend of Pb in the surface layer was consistent with that in the bottom layer. What’s more, from May to October, the seasonal variation of Pb content in the bottom layer of the water body in the southeastern Jiaozhou Bay was mainly decided by that of Pb content transported by the open ocean current. In the water body in the center of Jiaozhou Bay, the seasonal change of Pb content in the bottom layer was different from that in the surface layer and from that in the ocean current. In terms of time scale, in the waters from the southern bay mouth to the center of the bay, in May, August and October, the Pb content in the surface and the bottom layer changed in the same range, maintaining the consistency. Furthermore, in terms of spatial scale, in May and August, according to the high content and increasing trend of Pb transported by the open sea current, the horizontal distribution trend of Pb in the surface layer was opposite to that in the bottom layer. Nonetheless, in October, the Pb content transported by the open sea current was relatively low and showed a trend of decrease. And the horizontal distribution of Pb in the surface layer was consistent with that in the bottom layer.

scholarly journals The consistency of Arsenic’s high value regions in surface and bottom waters in Jiaozhou Bay

2018 ◽  
Vol 38 ◽  
pp. 01026
Author(s):  
Dongfang Yang ◽  
Jianxun Chai ◽  
Xiaoye Gao ◽  
Yunjie Wu ◽  
Sixi Zhu
Keyword(s):  
Surface Waters ◽  
Water Body ◽  
Coastal Waters ◽  
Jiaozhou Bay ◽  
Pollution Level ◽  
Wet Season ◽  
Guide Line ◽  
Sea Bottom ◽  
Bottom Waters ◽  
Overland Runoff

This paper analyzed the contents and distributions of As in Jiaozhou Bay in 1982. Results showed that As’s contents in bottom waters in coastal waters in the southwest of the bay and the bay mouth in Jiaozhou Bay in July and October 1982 were 0.88-4.48 μg L-1 and 0.84-1.16 μg L-1, respectively. As’s contents were much lower than the guide line of Grade I, and the pollution level of As in bottom waters in Jiaozhou Bay in 1982 was still very slight. There was high value region in coastal waters in the southwest of the bay in July 1982 (4.48 μg L-1), while in October 1982 high value region was in the bay mouth (1.16 μg L-1). The source input of As from overland runoff in the southwest was strong in July, resulted in relative high value region in surface waters in coastal waters in the southwest of the bay, and therefore resulted in high value region in bottom waters in same region by means of rapid sedimentation of As. October was wet season and there was little As input to the bay, resulted in low As’s contents in surface waters, as well as bottom waters. At any time, the terrigenous As was foremost transported to surface waters, and was subsided to sea bottom through water body by vertical water’s effect. Hence, the high value regions of As’s contents in surface and bottom waters had characteristic of consistency in Jiaozhou Bay.

scholarly journals Anthropogenic Influences on Dissolved Organic Matter in Three Coastal Bays, North China

2021 ◽  
Vol 9 ◽  
Author(s):  
Penghui Li ◽  
Chen Zhao ◽  
Ke Liu ◽  
Xiaotong Xiao ◽  
Yujue Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Dissolved Organic Matter ◽  
Bottom Water ◽  
North China ◽  
Jiaozhou Bay ◽  
Stable Carbon Isotope ◽  
River Mouth ◽  
Biological Production ◽  
Coastal Bays

Coastal bays bear anthropogenic influence strongly, and thus dissolved organic matter (DOM) in coastal bays, which is an important component of global carbon cycling, could be heavily affected by anthropogenic inputs. Utilizing absorbance, fluorescence spectroscopy, and stable carbon isotope (δ13C), this study analyzed the characteristics and distribution of DOM in three coastal bays (Jiaozhou Bay, Sishili Bay, and Taozi Bay), located in North China. The results showed that there was always a high concentration of DOM near the river mouth in all three bays and the DOM concentration decreased along the salinity gradient in Jiaozhou Bay, indicating the riverine inputs are the main factor that causes the variation of DOM in these coastal bays. The effects of inflowing rivers on DOM in coastal bays differed with their watershed characteristics (i.e., agricultural/urban). In addition, humic-like DOM components were found to be positively correlated with the apparent oxygen utilization, suggesting microbial activities could contribute to the DOM in this region. There was generally a higher averaged concentration of fluorescent DOM in surface water than that in bottom water in Jiaozhou Bay. In contrast, higher humic-like DOM was found in bottom water than that in surface water in Sishili Bay and Taozi Bay, which could be attributed to aquaculture activities and biological production. Moreover, photodegradation/photobleaching, dumping, and sewage discharge had their effects on DOM in coastal bays. This study demonstrates that DOM in coastal bays is regulated by multiple sources (rivers, aquaculture, dumping, and sewage) and processes (biological production and photodegradation), and anthropogenic activities have their influences on optical and isotopic characteristics of DOM in coastal bays.

scholarly journals Almost half of the Pb content leaving in the bottom of the sea

2021 ◽  
Vol 245 ◽  
pp. 02021
Author(s):  
Dongfang Yang ◽  
Minging Tian ◽  
Weifeng Ling ◽  
Qi Wang ◽  
Haixia Li
Keyword(s):  
Surface Layer ◽  
Water Body ◽  
Jiaozhou Bay ◽  
Bottom Layer ◽  
Matter Content ◽  
Change Model ◽  
Horizontal Migration ◽  
Sea Current ◽  
Vertical Changes ◽  
High Sediment

Using survey data of Pb in water body from southwest of Jiaozhou Bay to west of bay mouth, in August 1992 and according to the horizontal change model and the vertical change model of matter content put forward by authors, we calculate the horizontal loss amount, vertical diluted amount and vertical sediment amount of Pb in surface and bottom layer and determine the model diagram of Pb content horizontal and vertical changes. The results showed that in August, the absolutely horizontal loss amount of Pb content in surface layer and bottom layer was 8.92μg/L, and the relatively horizontal loss amount of Pb content was 56.10%. The absolutely horizontal increase amount of Pb was 5.74μg/L in bottom layer, and the relatively horizontal increase amount was 42.23%. In the southwestern waters of the bay, the absolutely vertical diluted amount of Pb was 8.05μg/L in both surface and bottom layer, and the relatively vertical diluted amount was 50.62%. Meanwhile, in the western waters of bay mouth, Pb content in the surface and bottom layer had an absolutely vertical sediment amount of 6.61μg/L and a relatively vertical sediment amount of 48.63%. From the southwestern waters of the bay to the western waters of the bay mouth, a large amount of Pb content in the surface layer is deposited on the seabed. Therefore, during the horizontal migration of Pb content on the surface, the loss was nearly 60.00% when the current left the bay. However, Pb content in the bottom layer increased by 42.23% during its horizontal migration. Thus, the high Pb content in the surface layer is retained at the bottom of Jiaozhou Bay. When the current left the inside of the bay, Pb content in the surface layer was relatively high with the vertical diluted amount of Pb content in the surface layer and bottom layer reaching almost 50%. When the main sea current reached the western part of the bay mouth, the Pb content in the surface layer could settle on the seabed rapidly and continuously with a high sediment amount of 48.63%.

Distribution of antifouling biocides in a coastal area of Tanabe Bay, Japan

2021 ◽  
pp. 1-11
Author(s):  
Hiroya Harino ◽  
Shigeyuki Yamato
Keyword(s):  
Surface Water ◽  
Water Samples ◽  
Bottom Water ◽  
Dry Weight ◽  
Water And Sediment ◽  
Irgarol 1051 ◽  
Average Residue ◽  
Bottom Waters ◽  
Residue Levels ◽  
Low Levels

Abstract Tributyltin (TBT) and triphenyltin (TPT) concentrations in water samples from Tanabe Bay were found to range from 4–28 ng l−1 and 3–7 ng l−1, respectively. In fishing ports, the concentrations of TBT in surface water were similar to those in bottom water. However, in aquafarming areas with poor flushing, the concentrations of TBT in bottom water were higher than those in surface water. This suggested that the TBT in water samples is re-eluted from sediment. No difference in the concentration of TPT was observed between the surface and bottom waters. The concentrations of TBT and TPT in sediment samples ranged from 3–23 μg kg−1 dry weight and 2–37 μg kg−1 dry weight. TBT and TPT concentrations ranged from 3.1–100 μg kg−1 and 3.1–7.2 μg kg−1 in oysters and gastropods, and from 1.1–4.9 μg kg−1 and ＜0.2–3.9 μg kg−1 in fish, respectively. Organotin concentrations in biota were lower than the tolerable average residue levels (TARLs). Alternative biocides – i.e. diuron, chlorothalonil, dichlofluanid, irgarol 1051 and Sea-Nine 211 – were also detected in surface water, and chlorothalonil and irgarol 1051 were detected in sediment. The concentrations of these compounds in surface water and sediment were lower than those reported previously. Dichlofluanid, chlorotharonil and irgarol 1051 were also found at low levels in oysters and gastropods, and at ranges of 325–339 μg kg−1, 268–291 μg kg−1 and 43–49 μg kg−1, respectively, in fish; the concentrations in fish were close to the TARL levels.

scholarly journals Variations Size Investigation in Vegetation and Surface Water Body for Central Part of Iraq using Satellite Imagery Bands

2020 ◽  
Vol 928 ◽  
pp. 022064
Author(s):  
Malik R. Abbas ◽  
Mahir Mahmod Hason ◽  
Baharin Bin Ahmad ◽  
Abd Wahid Bin Rasib ◽  
Talib R. Abbas
Keyword(s):  
Surface Water ◽  
Satellite Imagery ◽  
Water Body ◽  
Surface Water Body

scholarly journals Unsupervised Sub-Pixel Water Body Mapping with Sentinel-3 OLCI Image

2019 ◽  
Vol 11 (3) ◽  
pp. 327 ◽  
Author(s):  
Xia Wang ◽  
Feng Ling ◽  
Huaiying Yao ◽  
Yaolin Liu ◽  
Shuna Xu
Keyword(s):  
Surface Water ◽  
Real Time ◽  
Spatial Resolution ◽  
Water Body ◽  
Land Surface ◽  
Clustering Algorithm ◽  
Body Mapping ◽  
Water Index ◽  
Land Surface Water ◽  
Body Map

Mapping land surface water bodies from satellite images is superior to conventional in situ measurements. With the mission of long-term and high-frequency water quality monitoring, the launch of the Ocean and Land Colour Instrument (OLCI) onboard Sentinel-3A and Sentinel-3B provides the best possible approach for near real-time land surface water body mapping. Sentinel-3 OLCI contains 21 bands ranging from visible to near-infrared, but the spatial resolution is limited to 300 m, which may include lots of mixed pixels around the boundaries. Sub-pixel mapping (SPM) provides a good solution for the mixed pixel problem in water body mapping. In this paper, an unsupervised sub-pixel water body mapping (USWBM) method was proposed particularly for the Sentinel-3 OLCI image, and it aims to produce a finer spatial resolution (e.g., 30 m) water body map from the multispectral image. Instead of using the fraction maps of water/non-water or multispectral images combined with endmembers of water/non-water classes as input, USWBM directly uses the spectral water index images of the Normalized Difference Water Index (NDWI) extracted from the Sentinel-3 OLCI image as input and produces a water body map at the target finer spatial resolution. Without the collection of endmembers, USWBM accomplished the unsupervised process by developing a multi-scale spatial dependence based on an unsupervised sub-pixel Fuzzy C-means (FCM) clustering algorithm. In both validations in the Tibet Plate lake and Poyang lake, USWBM produced more accurate water body maps than the other pixel and sub-pixel based water body mapping methods. The proposed USWBM, therefore, has great potential to support near real-time sub-pixel water body mapping with the Sentinel-3 OLCI image.

scholarly journals Downscaling MODIS Surface Reflectance to Improve Water Body Extraction

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Xianghong Che ◽  
Min Feng ◽  
Hao Jiang ◽  
Jia Song ◽  
Bei Jia
Keyword(s):  
Surface Water ◽  
Water Body ◽  
Terrestrial Ecosystems ◽  
Water Area ◽  
Water Bodies ◽  
Tibet Plateau ◽  
Surface Reflectance ◽  
Discrimination Ability ◽  
Automated Method ◽  
Landsat 7

Inland surface water is essential to terrestrial ecosystems and human civilization. Accurate mapping of surface water dynamic is vital for both scientific research and policy-driven applications. MODIS provides twice observation per day, making it perfect for monitoring temporal water dynamic. Although MODIS provides two bands at 250 m resolution, accurately deriving water area always depends on observations from the spectral bands with 500 m resolution, which limits its discrimination ability over small lakes and rivers. The paper presents an automated method for downscaling the 500 m MODIS surface reflectance (SR) to 250 m to improve the spatial discrimination of water body extraction. The method has been tested at Co Ngoin and Co Bangkog in Qinghai-Tibet plateau. The downscaled SR and the derived water bodies were compared to SR and water body mapped from Landsat-7 ETM+ images were acquired on the same date. Consistency metrics were calculated to measure their agreement and disagreement. The comparisons indicated that the downscaled MODIS SR showed significant improvement over the original 500 m observations when compared with Landsat-7 ETM+ SR, and both commission and omission errors were reduced in the derived 250 m water bodies.

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