scholarly journals Investigation of Water Quality in the Agricultural Area of Lithuanian Karst Region

2017 ◽  
Author(s):  
Aurelija Rudzianskaitė
Keyword(s):  
Water Quality ◽  
Agricultural Area ◽  
Karst Region

scholarly journals Evaluation of Seasonal Groundwater Quality Changes Associated with Groundwater Pumping and Level Fluctuations in an Agricultural Area, Korea

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 51
Author(s):  
Kyoochul Ha ◽  
Eunhee Lee ◽  
Hyowon An ◽  
Sunghyun Kim ◽  
Changhui Park ◽  
...  
Keyword(s):  
Water Quality ◽  
Groundwater Quality ◽  
Groundwater Level ◽  
Irrigation Water ◽  
Agricultural Area ◽  
Water Type ◽  
Quality Changes ◽  
Groundwater Pumping ◽  
Rice Paddies ◽  
Groundwater Levels

This study was conducted to evaluate seasonal groundwater quality due to groundwater pumping and hydrochemical characteristics with groundwater level fluctuations in an agricultural area in Korea. Groundwater levels were observed for about one year using automatic monitoring sensors, and groundwater uses were estimated based on the monitoring data. Groundwater use in the area is closely related to irrigation for rice farming, and rising groundwater levels occur during the pumping, which may be caused by the irrigation water of rice paddies. Hydrochemical analysis results for two separate times (17 July and 1 October 2019) show that the dissolved components in groundwater decreased overall due to dilution, especially at wells in the alluvial aquifer and shallow depth. More than 50% of the samples were classified as CaHCO3 water type, and changes in water type occurred depending on the well location. Water quality changes were small at most wells, but changes at some wells were evident. In addition, the groundwater quality was confirmed to have the effect of saltwater supplied during the 2018 drought by comparison with seawater. According to principal component analysis (PCA), the water quality from July to October was confirmed to have changed due to dilution, and the effect was strong at shallow wells. In the study areas where rice paddy farming is active in summer, irrigation water may be one of the important factors changing the groundwater quality. These results provide a qualitative and quantitative basis for groundwater quality change in agricultural areas, particularly rice paddies areas, along with groundwater level and usage.

scholarly journals Variation Characteristics of the Main Hydrochemical Indexes in Typical Subterranean Rivers in the South China Karst Region Based on Curve Fitting

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Shuyi Liu ◽  
Chuan Liang ◽  
Lina Wang ◽  
Lingwei Zeng ◽  
Chunyi Wang
Keyword(s):  
Water Quality ◽  
South China ◽  
Spline Interpolation ◽  
Correlation Coefficients ◽  
Industrial Society ◽  
Karst Region ◽  
The South ◽  
Karst Areas ◽  
Variation Characteristics

The water quality of subterranean rivers in the South China Karst region has undergone dramatic changes resulting from industrial and social development over the past 60 years. The combination of sampling results from subterranean rivers in four typical study areas in the South China Karst region from October to December 2015 (dry season) and correlation analysis using SPSS revealed that the main ions K+, Na+, and SO42- exhibited a significant correlation (p<0.01) and that Ca2+, HCO3-, and Mg2+ exhibited a good correlation (p<0.01). Additionally, we consolidated the data collected since 1960 and, by applying MATLAB, a variety of fitting curve methods were used to fit all the data, and the results showed that cubic spline interpolation fitting performed the best. The squared correlation coefficients (R2) of the obtained fitting curves for Ca2+, HCO3-, and Mg2+ are 0.8545, 0.8689, and 0.7632, respectively, and the corrected R2 values are 0.6739, 0.7088, and 0.4853, respectively. The R2 values of the obtained fitting curves for K+, Na+, Cl-, SO42-, and NO3- are 0.9085, 0.8964, 0.7531, 0.6222, and 0.7997, respectively, and the corrected R2 values are 0.7904, 0.7669, 0.5272, 0.2815, and 0.6127, respectively, indicating excellent fits. Based on the fitting curves, the overall water quality conditions in the karst region were analyzed and compared. Finally, the development of subterranean rivers in the South China Karst region was determined. Based on the results, the following conclusions can be drawn: the development of the subterranean rivers is indeed a slow process, but water quality can change rapidly in response to the transformation of industrial society. Additionally, the results indicate the crucial importance of urban planning that takes into account environmental protection during development in karst regions. This study aims to provide a basis for the management of karst areas and the improvement of groundwater quality by evaluating geochemical processes.

Field laboratory for an appropriate water treatment in a tropical karst region

2014 ◽  
Vol 9 (4) ◽  
pp. 483-490 ◽  
Author(s):  
K. Matthies ◽  
M. Mendes de Oliveira ◽  
U. Obst
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Waste Water Treatment ◽  
Karst Region ◽  
Uv Disinfection ◽  
Efficient Technology ◽  
Water Shortages ◽  
Local Conditions ◽  
Field Laboratory ◽  
Ceramic Filtration

The district of Gunung Kidul in Southern Java is one of the poorest regions in Indonesia. It is located above a big karst formation with very poor filtration and low storage capacity, which lead to vulnerable water quality all year round and acute water shortages in the dry season. Deficient waste water treatment combined with fast and direct infiltration into the karst results in high levels of contamination in the groundwater, which is used for drinking. To improve the water quality, a three-step water treatment concept was developed and selected technologies were examined in a field laboratory for their disinfection efficiency under local conditions: chlorination, UV disinfection, and ceramic filtration. The first results suggested that UV disinfection is effective, but might be too vulnerable, that chlorination seemed not to be reliable under local conditions, and that ceramic filtration seemed to be the most efficient technology.

scholarly journals Lithuanian karst region rivers' water ecology: hydrochemical and hydrobiological evaluation

2004 ◽  
Vol 35 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Rimvydas Tumas
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Point Sources ◽  
Biotic Index ◽  
Karst Region ◽  
Agricultural Activity ◽  
Nitrogen And Phosphorus ◽  
Stream Pollution ◽  
Biological Water ◽  
Biological Water Quality

The Lithuanian karst region covers about 1000 km3 in the northern part of the country. This is the most vulnerable area from a pollution point of view. The structure of the total dissolved solids (TDS) shows that the flow of rivers in the karst region is from hydraulically interconnected aquifers. For the last decade (1991–2000) TDS has varied considerably, from 529 to 732 mg/l. The predominant sources of nitrogen and phosphorus within the headwaters of the monitored rivers were diffuse and agricultural in nature. Downstream from the towns nitrogen and especially phosphorus showed both diffuse and point source signals. Contributions of point sources to the stream pollution by nutrients prevail. The time series of monthly dissolved oxygen (O2) in the main karst region river – the Musa – shows the existence of multiplicative seasonality. The trend cycle (1991–1999) shows low levels of dissolved oxygen in 1991–1993, with a similar fluctuation in 1994, 1995 and 1996 (due to point pollution from the town of Siauliai) and a gradually improving situation since 1997. The general multiplicative trend of dissolved oxygen in the lower reaches of the Musa river (near the border with Latvia) is decreasing (within the accuracy limits). The abundance and species of zoo benthos are suitable criteria (biotic index – BI) for evaluation of a river's biological water quality. Zoo benthos demonstrates tolerances that vary among species, the oxygen regime and the pollution with nitrogen. The best living conditions for invertebrates are in the riverhead of the karst region rivers – BI=5.62–6.74 (1991–1999), where pollution with nutrients is caused mostly by agricultural activity. Rare and asynchronous data of biological water quality shows up tendencies that invertebrates prefer less contaminated reaches of rivers.

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