scholarly journals Analysis of ecotoxicological condition of Amur bay (the sea of Japan) based on chemical and toxicological indicators

2019 ◽  
Vol 46 (3) ◽  
pp. 308-317
Author(s):  
S. A. Cherkashin ◽  
M. V. Simokon ◽  
T. S. Pryazhevskaya
Keyword(s):  
Survival Rate ◽  
Surface Water ◽  
Bottom Sediments ◽  
Biological Effects ◽  
Outer Part ◽  
Water Area ◽  
The Sea Of Japan ◽  
Amur Bay ◽  
Marine Crustaceans ◽  
Biological Tests

Data on the Cd, Cu, Pb, and Zn contents in the bottom sediments of Amur Bay are presented. Contamination of bottom sediments is particularly heavy near the central part of Vladivostok, where the concentration of all metals, except for Cd, exceeds the threshold levels, at which negative biological effects are possible. Biological tests of marine crustaceans were conducted between 2003 and 2014 on water toxicity in this most contaminated bay water area. However, only in August 2003, September 2003, and July 2007, the survival rate of mysids in the surface water of the entire inner area was credibly lower than that in the outer part of the bay. In the following years, the ecotoxicological condition of the bay water improved owing to the decrease in contamination.

scholarly journals Influence of inter-annual variability of river runoff on the bottom sediments of the Razdolnaya River estuary, Primorye, Russia

2020 ◽  
Author(s):  
В.М. ШУЛЬКИН
Keyword(s):  
Grain Size ◽  
Chemical Composition ◽  
Bottom Sediments ◽  
River Runoff ◽  
Total Concentration ◽  
Outer Part ◽  
River Estuary ◽  
Size Composition ◽  
Amur Bay ◽  
The North

Изучены вариации гранулометрического и химического состава верхнего двухсантиметрового слоя донных отложений эстуария р. Раздольная, отобранных трижды в течение 2015–2019 гг., когда водный и твердый стоки реки выросли в 2–3 и 5–6 раз соответственно по сравнению с 2014 г. Показано, что значительный вынос осадочного материала сопровождается увеличением на 10–20 % доли пелитовых (<0,01мм) фракций в отложениях внешней части эстуария в северной части Амурского залива. Вариации гранулометрического состава являются главным контролирующим фактором и определяют 67 % общей изменчивости химического состава осадков эстуария. Еще 20 % изменчивости обусловлены примесью загрязненных отложений залива, содержащих повышенную концентрацию Сорг., Hg, Zn, Pb, Cd, Ag, Cu, Mo, V, а также восстановительным диагенезом, приводящим к обеднению осадков марганцем и кобальтом на разрезе река–море. Установить влияние коагуляционных процессов в зоне смешения на валовый состав донных отложений эстуария р. Раздольная не удалось. Grain size and chemical composition have been studied of the upper 2 cm layer of bottom sediments of the Razdolnaya River estuary sampled thrice in 2015–2019. It was a period when the river runoff increased by 2–3 and 5–6 times for the water and suspended solids, respectively, compared to 2014. It has been shown that significant subtraction of sedimentary material is accompanied by 10–20 % increase of pellite fractions (grain size <0.01 mm) in the deposits of the outer part of anestuary in the North part of the Amur Bay. Grain size composition is the main controlling factor determining 67 % of the total variability of the chemical composition of estuarine bottom sediments. Another 20 % of variability are due to the admix of polluted sediments of the Amur Bay, containing an increased concentration of Corg., Hg, Zn, Pb, Cd, Ag, Cu, Mo, V, as well as diagenesis, leading to depletion of sediments by the Mn and Co on a river-sea section. It is not possible to establish the influence of coagulation processes in the mixing zone on total concentration of trace elements in the bottom sediments of Razdolnaya River estuary.

Methane Fluxes at the Water–Atmosphere Interface and Gas-Geochemical Anomalies in the Bottom Sediments in the Northwestern Part of the Sea of Japan

2021 ◽  
Vol 62 (12) ◽  
pp. 1385-1400
Author(s):  
G.I. Mishukova ◽  
A.V. Yatsuk ◽  
R.B. Shakirov ◽  
N.S. Syrbu ◽  
M.G. Valitov ◽  
...  
Keyword(s):  
Sea Of Japan ◽  
Bottom Sediments ◽  
Sediment Cores ◽  
Methane Emissions ◽  
Water Area ◽  
The Sea Of Japan ◽  
Northwestern Part ◽  
Central Basin ◽  
Gas Dispersion ◽  
Methane Fluxes

Abstract —We present results of an integrated research into the spatial distribution of methane in the area of the northern closure of the Central Basin of the Sea of Japan and in the southern part of the Tatar Trough. Methane emissions have been revealed in the study area. The methane fluxes are distributed unevenly within the area (1 to 23 mol/(km2·day)). The discrete high-frequency measurements and calculation of methane fluxes at the water–atmosphere interface, combined with the study of the content of natural gases and microbiologic parameters in sediment cores, allow us to explain the formation of local methane emission zones in the water area. Despite the great sea depths, there are sources and fluid-conducting zones that determine methane concentrations (exceeding the equilibrium ones) and high methane emissions from the water area. The data obtained provide new information and suggest the presence of deep gas sources, which determine gas dispersion in the bottom sediments, the methane content in the surface water layer, and the distribution of methane fluxes at the water–atmosphere interface in the study area. This study is part of the integrated program of geological and geophysical expeditionary research performed by V.I. Il’ichev Pacific Oceanological Institute (Vladivostok) in the northern part of the Sea of Japan.

scholarly journals Surface Water Extraction and Dynamic Analysis of Baiyangdian Lake Based on the Google Earth Engine Platform Using Sentinel-1 for Reporting SDG 6.6.1 Indicators

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 138
Author(s):  
Zijie Jiang ◽  
Weiguo Jiang ◽  
Ziyan Ling ◽  
Xiaoya Wang ◽  
Kaifeng Peng ◽  
...  
Keyword(s):  
Sustainable Development ◽  
Surface Water ◽  
Essential Element ◽  
Water Area ◽  
Google Earth ◽  
Water Extraction ◽  
Natural Ecosystem ◽  
The Sustainable Development ◽  
Baiyangdian Lake ◽  
Google Earth Engine

Surface water is an essential element that supports natural ecosystem health and human life, and its losses or gains are closely related to national or local sustainable development. Monitoring the spatial-temporal changes in surface water can directly support the reporting of progress towards the sustainable development goals (SDGs) outlined by the government, especially for measuring SDG 6.6.1 indicators. In our study, we focused on Baiyangdian Lake, an important lake in North China, and explored its spatiotemporal extent changes from 2014 to 2020. Using long-term Sentinel-1 SAR images and the OTSU algorithm, our study developed an automatic water extraction framework to monitor surface water changes in Baiyangdian Lake at a 10 m resolution from 2014 to 2020 on the Google Earth Engine cloud platform. The results showed that (1) the water extraction accuracy in our study was considered good, showing high consistency with the existing dataset. In addition, it was found that the classification accuracy in spring, summer, and fall was better than that in winter. (2) From 2014 to 2020, the surface water area of Baiyangdian Lake exhibited a slowly rising trend, with an average water area of 97.03 km2. In terms of seasonal variation, the seasonal water area changed significantly. The water areas in spring and winter were larger than those in summer and fall. (3) Spatially, most of the water was distributed in the eastern part of Baiyangdian Lake, which accounted for roughly 57% of the total water area. The permanent water area, temporary water area, and non-water area covered 49.69 km2, 97.77 km2, and 171.55 km2, respectively. Our study monitored changes in the spatial extent of the surface water of Baiyangdian Lake, provides useful information for the sustainable development of the Xiong’an New Area and directly reports the status of SDG 6.6.1 indicators over time.

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.

scholarly journals Influence of Bottom Sediments Physicochemical Characteristics on Distribution of Microelements in the Crimean Shelf Water Areas

2020 ◽  
Author(s):  
E. A. Kotelyanets ◽  
K. I. Gurov ◽  
◽  
Keyword(s):  
Heavy Metals ◽  
Trace Elements ◽  
Spatial Distribution ◽  
Organic Carbon ◽  
Bottom Sediments ◽  
Clay Fraction ◽  
Zinc Content ◽  
Physicochemical Characteristics ◽  
Water Area ◽  
Pollution Level

The paper presents the results of studies of the Kalamitsky Bay bottom sediments pollution level with microelements and heavy metals (Pb, Zn, Cu, Ni, Co, Cr, V, As, Sr, Ti, Fe, Mn) in comparison with the content of these microelements and heavy metals in the Balaklava Bay sediments. The paper analyzes data obtained during expeditions on the R/V Professor Vodyanitsky in the Kalamitsky Gulf in August 2011 (seaward part) and on the R/V Rioni in September 2012 (coastal area) as well as in the Balaklava Bay in October 2018. Content of microelements and heavy metals in bottom sediments of the studied water areas was determined by the X-ray fluorescence method using Spectroscan MAX-G device. For the water area of the Kalamitsky Gulf, the features of the studied trace element spatial distribution are considered, groups of trace elements with different spatial distribution patterns are identified. The correlation analysis determined influence of physicochemical characteristics of the sediments on distribution and accumulation of trace elements. In the water area of the Kalamitsky Gulf, a statistically significant correlation was observed of nickel, iron and zinc content with the clay fraction; dependance of increased concentrations of zinc, nickel and chrome on the content of organic carbon and predominance of lead in highcarbonate sediments. For the Balaklava Bay, the maximum positive values of correlations with the pelitic-silty fraction were noted for iron, manganese, vanadium and chrome; organic carbon correlates with chrome, iron, nickel and copper, whereas carbonates correlate with strontium. Similar patterns were observed earlier in the Sevastopol region bays, Feodosiya Gulf and Kerch Strait.

scholarly journals Monitoring monthly surface water dynamics of Dongting Lake using Sentinal-1 data at 10 m

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4992 ◽  
Author(s):  
Liwei Xing ◽  
Xinming Tang ◽  
Huabin Wang ◽  
Wenfeng Fan ◽  
Guanghui Wang
Keyword(s):  
Surface Water ◽  
Water Distribution ◽  
Remote Sensing Data ◽  
Water Area ◽  
Dongting Lake ◽  
Water Dynamics ◽  
High Temporal Resolution ◽  
Backscattering Coefficient ◽  
Distribution Maps ◽  
Lower Accuracy

High temporal resolution water distribution maps are essential for surface water monitoring because surface water exhibits significant inner-annual variation. Therefore, high-frequency remote sensing data are needed for surface water mapping. Dongting Lake, the second-largest freshwater lake in China, is famous for the seasonal fluctuations of its inundation extents in the middle reaches of the Yangtze River. It is also greatly affected by the Three Gorges Project. In this study, we used Sentinel-1 data to generate surface water maps of Dongting Lake at 10 m resolution. First, we generated the Sentinal-1 time series backscattering coefficient for VH and VV polarizations at 10 m resolution by using a monthly composition method. Second, we generated the thresholds for mapping surface water at 10 m resolution with monthly frequencies using Sentinel-1 data. Then, we derived the monthly surface water distribution product of Dongting Lake in 2016, and finally, we analyzed the inner-annual surface water dynamics. The results showed that: (1) The thresholds were −21.56 and −15.82 dB for the backscattering coefficients for VH and VV, respectively, and the overall accuracy and Kappa coefficients were above 95.50% and 0.90, respectively, for the VH backscattering coefficient, and above 94.50% and 0.88, respectively, for the VV backscattering coefficient. The VV backscattering coefficient achieved lower accuracy due to the effect of the wind causing roughness on the surface of the water. (2) The maximum and minimum areas of surface water were 2040.33 km2in July, and 738.89 km2in December. The surface water area of Dongting Lake varied most significantly in April and August. The permanent water acreage in 2016 was 556.35 km2, accounting for 19.65% of the total area of Dongting Lake, and the acreage of seasonal water was 1525.21 km2. This study proposed a method to automatically generate monthly surface water at 10 m resolution, which may contribute to monitoring surface water in a timely manner.

scholarly journals Видовое многообразие и территориальное распределение наземных позвоночных Tetrapoda (Vertebrata, Chordata) Приморского края

2020 ◽  
Author(s):  
Ю.Н. Глущенко ◽  
Э.И. Цунов
Keyword(s):  
Species Diversity ◽  
Sea Of Japan ◽  
Water Area ◽  
The Sea Of Japan ◽  
Primorsky Krai ◽  
Adjacent Water

В публикации дано видовое многообразие и территориальное распределение наземных позвоночных Tetrapoda (Vertebrata, Gnathostomata), известных для территории Приморского края и прилежащей акватории Японского моря. Ключевые слова: Приморский край, наземные позвоночные, Tetrapoda, видовое многообразие, распространение. The publication presents the species diversity and territorial distribution of superclass Tetrapoda (Vertebrata, Chordata), known for the territory of PrimorskyKrai and the adjacent water area of the Sea of Japan. Keywords: Primorsky Krai, Tetrapoda, species diversity, territorial distribution.

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