scholarly journals Spatio-Temporal Variations of Hydrochemical and Microbial Characteristics in Karst Water in Samcheok, South Korea

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3407
Author(s):  
Han-Sun Ryu ◽  
Heejung Kim ◽  
Jin-Yong Lee ◽  
Jiwook Jang ◽  
Sangwook Park

This study analyzed the hydrochemical characteristics and microbial communities of karst water in Samcheok, Korea, and compared water quality results to identify the seasonal characteristics and hydrogeological connectivity of the study areas of Hamaengbang-ri, Gyogok-ri, Yeosam-ri, and the downtown area of Samcheok. Field survey and water quality analysis were performed in July 2019, February 2020, and April 2020. Hydrochemical analysis of karst water (groundwater and surface water) showed that most samples were comprised of Ca-HCO3 and that water–rock interactions were a dominant factor compared to precipitation and evaporation (crystallization). For seasonal characteristics, water–rock interactions appeared more active in the dry season than in the rainy season. Calcite weathering was dominant in the dry season, whereas dolomite weathering dominated the rainy season. Moreover, the saturation indexes for the dry and rainy seasons were less than and greater than 0, respectively, corresponding to an unsaturation (oversaturation) state; thus, white precipitate distributed in the study areas was deposited in the rainy season. Finally, as a result of analyzing the hydraulic characteristics between regions, hydrogeological similarities were identified between Hamaengbang-ri and Yeosam-ri, and between Gyogok-ri and downtown Samcheok, which suggested hydrogeological connectivity between each of the pairs.

2020 ◽  
pp. 14-27
Author(s):  
Giao Thanh Nguyen ◽  
Huynh Thi Hong Nhien

The study aims to assess spatial and temporal water quality variations in the upper reaches of the Vietnamese Mekong Delta. Thirty-one water monitoring samples of the two main rivers (Tien and Hau Rivers) and six canals flowing through An Giang Province were collected in the dry season (March) and the rainy season (September) from 2009 to 2019. Seven physicochemical parameters were analyzed including temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), total suspended solids (TSS), orthophosphate (P-PO43-), and coliforms. Water quality index (WQI), cluster analysis (CA), and discriminant analysis (DA) were applied to evaluate water quality, spatial and temporal variations, and seasonal discriminant water variables. WQI values (15–71) indicated surface water quality was very bad to medium in which the water quality in larger and in smaller rivers in the dry season was less polluted than that in the rainy season due to erosion and runoff water containing waste materials in the wet season. CA grouped the water quality in the dry and rainy seasons into four clusters mainly due to BOD and coliforms in the dry season; TSS and coliforms in the rainy season. Discriminant analysis revealed that DO, TSS, coliforms, temperature and BOD significantly contributed to seasonal variations in water quality. Therefore, water quality monitoring in the surveyed area could only focus on DO, TSS, coliforms, temperature and BOD to reduce monitoring cost.


Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2699 ◽  
Author(s):  
Jian Li ◽  
Liqiao Tian ◽  
Qingjun Song ◽  
Zhaohua Sun ◽  
Hongjing Yu ◽  
...  

Monitoring of water quality changes in highly dynamic inland lakes is frequently impeded by insufficient spatial and temporal coverage, for both field surveys and remote sensing methods. To track short-term variations of chlorophyll fluorescence and chlorophyll-a concentrations in Poyang Lake, the largest freshwater lake in China, high-frequency, in-situ, measurements were collected from two fixed stations. The K-mean clustering method was also applied to identify clusters with similar spatio-temporal variations, using remote sensing Chl-a data products from the MERIS satellite, taken from 2003 to 2012. Four lake area classes were obtained with distinct spatio-temporal patterns, two of which were selected for in situ measurement. Distinct daily periodic variations were observed, with peaks at approximately 3:00 PM and troughs at night or early morning. Short-term variations of chlorophyll fluorescence and Chl-a levels were revealed, with a maximum intra-diurnal ratio of 5.1 and inter-diurnal ratio of 7.4, respectively. Using geostatistical analysis, the temporal range of chlorophyll fluorescence and corresponding Chl-a variations was determined to be 9.6 h, which indicates that there is a temporal discrepancy between Chl-a variations and the sampling frequency of current satellite missions. An analysis of the optimal sampling strategies demonstrated that the influence of the sampling time on the mean Chl-a concentrations observed was higher than 25%, and the uncertainty of any single Terra/MODIS or Aqua/MODIS observation was approximately 15%. Therefore, sampling twice a day is essential to resolve Chl-a variations with a bias level of 10% or less. The results highlight short-term variations of critical water quality parameters in freshwater, and they help identify specific design requirements for geostationary earth observation missions, so that they can better address the challenges of monitoring complex coastal and inland environments around the world.


2015 ◽  
Vol 19 (2) ◽  
pp. 58-64
Author(s):  
Birendra Gautam ◽  
Rejina Maskey ◽  
Ramesh Prasad Sapkota ◽  
Dharma Raj Dangol

The present research was conducted to study seasonal limnological parameters and record composition pattern of aquatic macro-invertebrates of the Rampur Ghol. GRS-BIOS/ASPT index was used to calculate the water quality class, Shannon Weiner diversity index (H’) and Piélou evenness index (e) were used to determine taxa richness of the macroinvertebrates. Altogether 281 individuals of 14 families and 313 individuals of 18 families were recorded in dry season and rainy season, respectively. Similarly, diversity index and evenness index values were recorded 0.98 and 0.85 in dry season; 1.075 and 0.86 in rainy season. On the basis of different aquatic macro-invertebrates, GRS-BIOS/ASPT Index value of four sampling sites fall in class II (moderately polluted), four sampling sites belong to water quality class IIIII (critically polluted) and remaining two sampling sites belong to water quality class III (heavily polluted). Similarly, in rainy season seven sites fall in water quality class II (moderately polluted) and three sampling sites belong to water quality class II-III (critically polluted).Journal of Institute of Science and Technology, 2014, 19(2): 58-64


2019 ◽  
Vol 22 (2) ◽  
pp. 327-345 ◽  
Author(s):  
Geovanny Gordillo ◽  
Mario Morales-Hernández ◽  
Pilar García-Navarro

Abstract In this work, a one-dimensional (1D) finite volume numerical model for the unsteady simulation of the flow hydrodynamics and water quality is developed. The water dynamics is formulated with the 1D shallow water equations, and the water quality evolution is described by the Water Quality Analysis Simulation Program (WASP) model, allowing us to interpret and predict the transport and fate of various biochemical substances along any river reach. This combined system is solved with an explicit finite volume scheme based on Roe's linearization for the advection component of both the flow and the solute transport equations. The proposed model is able to consider temporal variations in tributaries and abstractions occurring in the river basin. This feature is transcendent in order to predict the chemical composition of natural water bodies during winter and summer periods, leading to an improvement in the agreement between computed and observed water quality evolutions. The combined model has been evaluated using literature tests in a steady state and a real-field case of the Ebro river (Spain), characterized by a marked unsteady regime. In the real case, we found that the water temperature was very sensitive to both the solar radiation and the average air temperature, requiring a careful calibration of these parameters. The numerical results are also demonstrated to be reasonably accurate, conservative and robust in real-scale field cases, showing that the model is able to predict the evolution of quality parameters as well as hydrodynamic variables in complex scenarios.


2017 ◽  
Vol 17 (6) ◽  
pp. 1507-1514 ◽  
Author(s):  
Cristiano Christofaro ◽  
Mônica M. Diniz Leão ◽  
Sílvia M. A. C. Oliveira ◽  
Déborah T. Viana ◽  
Camila C. Amorim ◽  
...  

2019 ◽  
Vol 19 (1) ◽  
pp. 57-66
Author(s):  
Le Thi Vinh ◽  
Nguyen Hong Thu ◽  
Pham Huu Tam ◽  
Le Trong Dung

The results of three surveys in the O Loan lagoon in the dry season (April 2013) and the rainy season (December 2012 and December 2014) showed that in the rainy season the average concentrations of nutrients in waters (ammonium: 76.8 μgN/l, nitrite: 13.9 μgN/l, nitrate: 55 μgN/l and silicate: 4021 μgSi/l) tended to be higher than those in the dry season (ammonium: 6.0 μgN/l, nitrite: 2.6 μgN/L, nitrate: 35 μgN/l and silicate: 1973 μgSi/l) while phosphate concentraiton did not differ between the two seasons with an average concentration of 66.8 μgP/l in rainy season and 60 μgP/L in dry season. By space, the concentrations of nutrients except nitrate in the lagoon, especially in the southern part, were usually higher than those in the canal connected to the sea. At O Loan lagoon waters, only ammonium (mainly in the southern part of the lagoon) and nitrate (mainly in the canal and southern part of the lagoon) concentrations were higher than the criteria values in the rainy season (December 2014) with pollution coefficient of about 1.2. However, the water quality of O Loan lagoon regarding nutrients always still needs to be monitored because from 1992 to the surveyed time, the concentrations of nutrients containing nitrogen and phosphate had the increasing trend in both seasons.


Caldasia ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 139-151
Author(s):  
Eduardo Villarreal ◽  
Neis Martínez ◽  
Catalina Romero-Ortiz

The Dry Tropical Forest (DTF) is one of the most diverse yet threatened biomes of Colombia. There is limited information about the richness of the order Pseudoscorpiones (Arachnida) in this ecosystem in the country. Pseudoscorpions are ecologically interesting, as they may be good indicators of habitat conservation. However, it is still necessary to gather more knowledge related to its spatio-temporal variation. In this study, pseudoscorpion diversity variation was assessed in two fragments of the Dry Tropical Forest in the Caribbean region of Colombian: Reserva Campesina La Montaña (RCM) and Reserva La Flecha (RLF). Four samplings were carried out between March and September of 2016 to include the dry and rainy season. Pseudoscorpions were collected using litter sifting (SL) and manual capture (MC). A total of 260 individuals belonging to five families and eight species were collected. The most abundant was Pachyolpium granulatum (Olpiidae) and the richest family was Chernetidae. The collection methods were effective and complementary. Spatial variation was significant, but no temporal variation was observed however, there was a marked difference between the abundance at RCM in the dry season and the rainy season. In contrast, at RLF most individuals were found in the dry season in comparison with the rainy season. These new faunistic data is the first of its order in the Atlántico and Bolívar department.


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