Assessing seasonal controls in silicon cycle and isotopic signatures of groundwater under anthropogenic stress in tropical watershed

2020 ◽  
Author(s):  
Sarath Pullyottum Kavil ◽  
Damien Cardinal ◽  
Jean Riotte ◽  
Arnaud Dapoigny ◽  
Laurent Ruiz ◽  
...  
Keyword(s):  
Land Use ◽  
Surface Water ◽  
Natural Waters ◽  
Dry Season ◽  
Silicon Isotope ◽  
Continuous Irrigation ◽  
Silicon Isotopes ◽  
Silicon Cycle ◽  
Groundwater Samples ◽  
South West Monsoon

<p>Intense irrigation along with extensive use of fertilizers significantly effects the hydrological and biogeochemical cycles in shallow aquifers. Land use changes associated with human activities are known to be a major controlling factor of the terrestrial silicon cycle, altering silicon fluxes to surface and groundwater. In the present study we determined dissolved silicon concentration (DSi) and δ<sup>30</sup>Si of shallow groundwater samples collected from bore wells and piezometers of two watersheds in Southern India under contrasting land use: one intensely cultivated (Berambadi) and one forested (Mule Hole).</p><p>Intense groundwater irrigation in the Berambadi region leads to water table depletion, progressive salinization and occurrence of nitrate hotspots in groundwater. We collected groundwater samples during two periods, during the summer (dry) season in March and during the South-West monsoon season in August from both watersheds. DSi values ranged from  410 µM to 1487 µM, with a lower value during August sampling indicating dilution effects caused by monsoon precipitation. Mule Hole and Berambadi aquifer recharge mostly occurs through surface water percolation or from lateral flow. Groundwater composition thus exhibits seasonal variation depending on precipitation which can be traced using water isotopes (δ<sup>18</sup>O and δ<sup>2</sup>H). The depleted values in Berambadi groundwater (average δ<sup>18</sup>O of -2.99 ‰ and δ<sup>2</sup>H of -15.86 ‰) compared to forested watershed in Mule Hole indicate higher contribution from meteoric water likely due to quicker turnover resulting from continuous irrigation.</p><p>Silicon isotope fractionation in natural waters is majorly controlled by soil-water interaction consisting in dissolution of primary minerals and formation of secondary minerals and also from biogenic sources and uptake.  Preliminary results show no significant differences in δ<sup>30</sup>Si signatures in groundwater from the two watersheds (1.1 ± 0.3 ‰) in dry season despite higher and more variable DSi concentration in cultivated watershed (1100 ± 260 µM vs. 790 ± 120 µM for the forest). Assuming similar discharge, higher DSi concentration in Berambadi during both seasons indicates increased export/mobilization of Si into aquifer when compared to forested landscape.</p><p>We will further refine our understanding of Si biogeochemistry in groundwater and the changes associated with land use by comparing the water and silicon isotopes with the germanium/silicon ratio and major element compositions in comparison with surface water data.</p>

The Effect of Land Use on Water Quality in Lam Takong Basin, Nakhon Ratchasima Province, Thailand

2014 ◽  
Vol 1030-1032 ◽  
pp. 641-647 ◽  
Author(s):  
Glinsukol Suwannarat ◽  
Pongthep Suwanwaree
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Surface Water ◽  
Chlorophyll A ◽  
Water Body ◽  
Treatment Plant ◽  
Water Quality Assessment ◽  
Industrial Area ◽  
Dry Season ◽  
Septic Tank

The water quality assessment of Lam Takong River and tributaries, from 20 stations, 6 times (October and December, 2008; February, April, June and August, 2009), revealed that overall water quality was in class 3 of Thailand surface water standard, except NH3-N, P and BOD. The maximum of NH3-N (12.6 mg/L), Phosphate 2.7 mg/L and BOD (8.7 mg/L) were found at Quartermaster Department Royal Thai Army Bridge, Nakhon Ratchasima Municipality pump in Lam Takong reservoir and Ban Ta Krasang, respectively, causing class 4 surface water standard in these areas. Moreover, trophic level of Lam Ta Khong River was mesotrophic; except they were meso-eutrophic after passing through Nakhon Ratchasima Municipality, Ban Ta Krasung, and Kan Pom dam before reaching Mool River. The season also affected on water quality. The value of pH, DO, BOD and NH3-N were significantly higher in dry season (p<0.01), while temperature, salinity and TSS were significantly lower in dry season (p<0.01). However, turbidity, TOC, NO3, NO2 and Chlorophyll-a in rainy season were higher than dry season but not statistically different. Pearson’s Correlation of 9 land use types on water quality showed that urban area was correlated with BOD, DO, NH3-N, PO4 and Chlorophyll-a (0.425, 0.380, -0.259, 0.445, and 0.339, respectively) higher than industrial area, scrub forest and water body. However, nitrate was mostly correlated with water body. Later, statistical models were developed from these results. WAPS was used to predict water quality in Lam Takong River. Three scenarios (present, 10 years, and 10 years with 25% BOD reduction) were simulated. The model predicts that water quality still decreases when flow through Nakhon Ratchasima Municipality. The minimum DO would reach 1 mg/L in ten years. However, if 25% BOD are reduced by future wastewater treatment plant and septic tank construction, the minimum DO would be 2.75 mg/L.

Modified enrichment and purification protocol for dissolved silicon-isotope determination in natural waters

2014 ◽  
Vol 29 (12) ◽  
pp. 2414-2418 ◽  
Author(s):  
Anyu Zhang ◽  
Jing Zhang ◽  
Ruifeng Zhang ◽  
Yun Xue
Keyword(s):  
Natural Waters ◽  
Silicon Isotope ◽  
Silicon Isotopes ◽  
Isotope Determination ◽  
Dissolved Silicon ◽  
Co Precipitation ◽  
Resin Separation ◽  
Purification Protocol

Single magnesium co-precipitation combined with resin separation to enrich and purify dissolved silicon for the determination of silicon isotopes.

STUDI BIONOMIK VEKTOR MALARIA DI KECAMATAN KALIBAWANG, KULONPROGO

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Sardjito Eko Windarso dkk
Keyword(s):  
Land Use ◽  
Malaria Vector ◽  
Rainy Season ◽  
Dry Season ◽  
Physical Factors ◽  
Mosquito Vector ◽  
Anopheles Species ◽  
Commercial Farming ◽  
Study Results ◽  
Dry And Rainy Seasons

The increasing of malaria cases in recent years at Kecamatan Kalibawang has been suspected correspond with the conversion of farming land-use which initiated in 1993. Four years after the natural vegetation in this area were changed become cocoa and coffee commercial farming estates, the number of malaria cases in 1997 rose more than six times, and in 2000 it reached 6085. This study were aimed to observe whether there were any differences in density and diversity of Anopheles as malaria vector between the cocoa and mix farming during dry and rainy seasons. The results of the study are useful for considering the appropriate methods, times and places for mosquito vector controlling. The study activities comprised of collecting Anopheles as well as identifying the species to determine the density and diversity of the malaria vector. Both activities were held four weeks in dry season and four weeks in rainy season. The mea-surement of physical factors such as temperature, humidity and rainfall were also conducted to support the study results. Four dusuns which meet the criteria and had the highest malaria cases were selected as study location. Descriptively, the results shows that the number of collected Anopheles in cocoa farming were higher compared with those in mix horticultural farming; and the number of Anopheles species identifi ed in cocoa farming were also more varied than those in the mix horticultural farming.Key words: bionomik vektor malaria, anopheles,

Phthalate esters in surface water of Songhua River watershed associated with land use types, Northeast China

2017 ◽  
Vol 25 (8) ◽  
pp. 7688-7698 ◽  
Author(s):  
Zhidan Wen ◽  
Xiaoli Huang ◽  
Dawen Gao ◽  
Ge Liu ◽  
Chong Fang ◽  
...  
Keyword(s):  
Land Use ◽  
Surface Water ◽  
Northeast China ◽  
Phthalate Esters ◽  
Songhua River ◽  
River Watershed ◽  
Land Use Types

scholarly journals Spatial variability of nitrate pollution and its sources in a hilly basin of the Yangtze River based on clustering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuhuan Cui ◽  
Jie Wang ◽  
Shuang Hao
Keyword(s):  
Surface Water ◽  
Yangtze River ◽  
Drainage Basin ◽  
Quality Standard ◽  
Nitrate Pollution ◽  
Middle Part ◽  
Lake Basin ◽  
The Yangtze River ◽  
Nitrate Sources ◽  
Groundwater Samples

AbstractNitrate (NO3−) pollution is a serious global problem, and the quantitative analysis of its sources contributions is essential for devising effective water-related environmental-protection policies. The Shengjin Lake basin, located in the middle to lower reaches of the Yangtze River in China was selected as the research area in our study. We first grouped 29 surface water samples and 33 groundwater samples using cluster analysis, and then analyzed potential nitrate sources for each dataset of δ15N–NO3− and δ18O–NO3− isotope values by applying a Bayesian isotope-mixing model. Our results show that the nitrogen pollution in the surface-ground water in the study area seriously exceeded to class V of the Environmental Quality Standard of Surface Water of China. The NO3− in surface water from the mid-upper reaches of the drainage basin mainly originates from soil nitrogen (SN) and chemical fertilizer (CF), with contribution rates of 48% and 32%, respectively, and the NO3− in downstream areas mainly originates from CF and manure and sewage (MS), with contribution rates of 48% and 33%, respectively. For the groundwater samples, NO3− mainly originates from MS, CF, and SN in the mid-upper reaches of the drainage basin and the northside of Dadukou near the Yangtze River, with contribution rates of 34%, 31%, and 29%, respectively, whereas NO3− in the lower reaches and the middle part of Dadukou mainly originates from MS, with a contribution rate of 83%. The nitrogen conversion of surface water in lakes and in the mid-upper reaches is mainly affected by water mixing, while the groundwater and surface water in the lower plains are mainly affected by denitrification. The method proposed in this study can expand the ideas for tracking nitrate pollution in areas with complex terrain, and the relevant conclusions can provide a theoretical basis for surface and groundwater pollution control in the hilly basin of Yangtze River.

On methodological approaches to the improvement of surface water bodies and target indicators of the natural waters’ quality

2021 ◽  
Vol 27 (1) ◽  
pp. 6-14
Author(s):  
V. Zaslonovsky ◽  
◽  
N. Sharapov ◽  
M. Bosov ◽  
◽  
...  
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Natural Water ◽  
Aquatic Ecosystems ◽  
Natural Waters ◽  
Water Bodies ◽  
Surface Water Bodies ◽  
Methodological Approaches ◽  
Natural Water Bodies

The paper is devoted to the development of proposals concerning the improvement of surface water bodies and the appointment of target indicators of the natural waters’ quality. The paper considers a variety of problems of preserving, restoring and improving the quality of natural surface waters: from regional features of the formation of natural water composition, to differences in the requirements for the quality of water consumed. The object of the study is the qualitative indicators of the waters of natural water bodies, and the subject of the study is the methodological approaches to the normalization of these indicators. The purpose of the work is to identify the main shortcomings in the domestic system of rationing the quality of natural waters, and to form appropriate proposals. For this purpose, the following tasks were set and solved: to review the methodological approaches to assessing and rationing the quality of natural waters used in some foreign countries and in the Russian Federation, to identify the main causes and shortcomings; to make proposals for improving the current system of water quality rationing. The result of this work is the conclusions about the lack of impact of the strategy operating in Russia in the development of schemes of complex use and protection of water objects, standards of permissible impact on water bodies, the appointment of permissible discharge limits in terms of maintaining and improving the water quality of natural water bodies. The reasons that led to this are indicated. The necessity of taking into account, in addition to the physical and chemical composition, also hydrobiological parameters is shown. It is concluded that instead of fisheries management standards, environmental standards should serve as the basis for target indicators of water quality of natural water bodies, which determine the well-being of humans and the stable functioning of aquatic ecosystems, taking into account regional factors. Proposals were made to adjust the methodological approaches to the implementation of this strategy. According to the authors, these proposals will speed up the solution of the main objectives of the strategy – the ecological improvement of water bodies, the preservation of unique aquatic ecosystems and the environmentally safe development of territories that previously experienced relatively small anthropogenic impacts (Eastern Siberia and the Far East)

Taking the pulse of Mother Ganga - Revealing the visible and invisible water pollution crisis along the Ganges River

2021 ◽  
Author(s):  
Stefan Krause ◽  
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Land Use ◽  
Surface Water ◽  
River Network ◽  
Ganges River ◽  
Sediment Samples ◽  
Water And Sediment ◽  
The Ganges ◽  
Water And Sediment Samples

&lt;p&gt;It is probably hard to overestimate the significance of the River Ganges for its spiritual, cultural and religious importance. As the worlds&amp;#8217; most populated river basin and a major water resource for the 400 million people inhabiting its catchment, the Ganges represents one of the most complex and stressed river systems globally. This makes the understanding and management of its water quality an act of humanitarian and geopolitical relevance. Water quality along the Ganges is critically impacted by multiple stressors, including agricultural, industrial and domestic pollution inputs, a lack and failure of water and sanitation infrastructure, increasing water demands in areas of intense population growth and migration, as well as the severe implications of land use and climate change. Some aspects of water pollution are readily visualised as the river network evolves, whilst others contribute to an invisible water crisis (Worldbank, 2019) that affects the life and health of hundreds of millions of people.&lt;/p&gt;&lt;p&gt;We report the findings of a large collaborative study to monitor the evolution of water pollution along the 2500 km length of the Ganges river and its major tributaries that was carried out over a six-week period in Nov/Dec 2019 by three teams of more than 30 international researchers from 10 institutions. Surface water and sediment were sampled from more than 80 locations along the river and analysed for organic contaminants, nutrients, metals, pathogen indicators, microbial activity and diversity as well as microplastics, integrating in-situ fluorescence and UV absorbance optical sensor technologies with laboratory sample preparation and analyses. Water and sediment samples were analysed to identify the co-existence of pollution hotspots, quantify their spatial footprint and identify potential source areas, dilution, connectivity and thus, derive understanding of the interactions between proximal and distal of sources solute and particulate pollutants.&lt;/p&gt;&lt;p&gt;Our results reveal the co-existence of distinct pollution hotspots for several contaminants that can be linked to population density and land use in the proximity of sampling sites as well as the contributing catchment area. While some pollution hotspots were characterised by increased concentrations of most contaminant groups, several hotspots of specific pollutants (e.g., microplastics) were identified that could be linked to specific cultural and religious activities. Interestingly, the downstream footprint of specific pollution hotspots from contamination sources along the main stem of the Ganges or through major tributaries varied between contaminants, with generally no significant downstream accumulation emerging in water pollution levels, bearing significant implications for the spatial reach and legacy of pollution hotspots. Furthermore, the comparison of the downstream evolution of multi-pollution profiles between surface water and sediment samples support interpretations of the role of in-stream fate and transport processes in comparison to patterns of pollution source zone activations across the channel. In reporting the development of this multi-dimensional pollution dataset, we intend to stimulate a discussion on the usefulness of large river network surveys to better understand the relative contributions, footprints and impacts of variable pollution sources and how this information can be used for integrated approaches in water resources and pollution management.&lt;/p&gt;

scholarly journals Estimating population and livestock density of mobile pastoralists and sedentary settlements in the south-eastern Lake Chad area

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Vreni Jean-Richard ◽  
Lisa Crump ◽  
Abbani Alhadj Abicho ◽  
Ali Abba Abakar ◽  
Abdraman Mahamat II ◽  
...  
Keyword(s):  
Land Use ◽  
Population Density ◽  
Small Ruminants ◽  
Dry Season ◽  
Land Use Management ◽  
Lake Chad ◽  
Mobile Pastoralists ◽  
Livestock Density ◽  
Density Dynamics ◽  
First Time

Mobile pastoralists provide major contributions to the gross domestic product in Chad, but little information is available regarding their demography. The Lake Chad area population is increasing, resulting in competition for scarce land and water resources. For the first time, the density of people and animals from mobile and sedentary populations was assessed using randomly defined sampling areas. Four sampling rounds were conducted over two years in the same areas to show population density dynamics. We identified 42 villages of sedentary communities in the sampling zones; 11 (in 2010) and 16 (in 2011) mobile pastoralist camps at the beginning of the dry season and 34 (in 2011) and 30 (in 2012) camps at the end of the dry season. A mean of 64.0 people per km2 (95% confidence interval, 20.3-107.8) were estimated to live in sedentary villages. In the mobile communities, we found 5.9 people per km2 at the beginning and 17.5 people per km2 at the end of the dry season. We recorded per km2 on average 21.0 cattle and 31.6 small ruminants in the sedentary villages and 66.1 cattle and 102.5 small ruminants in the mobile communities, which amounts to a mean of 86.6 tropical livestock units during the dry season. These numbers exceed, by up to five times, the published carrying capacities for similar Sahelian zones. Our results underline the need for a new institutional framework. Improved land use management must equally consider the needs of mobile communities and sedentary populations.

scholarly journals Waterborne Viruses and F-Specific Coliphages in Mixed-Use Watersheds: Microbial Associations, Host Specificities, and Affinities with Environmental/Land Use Factors

2016 ◽  
Vol 83 (3) ◽  
Author(s):  
Tineke H. Jones ◽  
Julie Brassard ◽  
Edward Topp ◽  
Graham Wilkes ◽  
David R. Lapen
Keyword(s):  
Land Use ◽  
Surface Water ◽  
Surface Waters ◽  
Water Samples ◽  
Land Development ◽  
Hepatitis E ◽  
Surface Water Flow ◽  
Mixed Use ◽  
Human Viruses ◽  
Waterborne Viruses

ABSTRACT From the years 2008 to 2014, a total of 1,155 water samples were collected (spring to fall) from 24 surface water sampling sites located in a mixed-used but predominantly agricultural (i.e., dairy livestock production) river basin in eastern Ontario, Canada. Water was analyzed for viable F-specific DNA (F-DNA) and F-specific RNA (F-RNA) (genogroup I [GI] to GIV) coliphage and a suite of molecularly detected viruses (norovirus [GI to GIV], torque teno virus [TTV], rotavirus, kobuvirus, adenovirus, astrovirus, hepatitis A, and hepatitis E). F-DNA and F-RNA coliphage were detected in 33 and 28% of the samples at maximum concentrations of 2,000 and 16,300 PFU · 100 ml−1, respectively. Animal TTV, human TTV, kobuvirus, astrovirus, and norovirus GIII were the most prevalent viruses, found in 23, 20, 13, 12, and 11% of samples, respectively. Viable F-DNA coliphage was found to be a modest positive indicator of molecularly detected TTV. F-RNA coliphage, unlike F-DNA coliphage, was a modest positive predictor of norovirus and rotavirus. There were, however, a number of significant negative associations among F-specific coliphage and viruses. F-DNA coliphage densities of >142 PFU · 100 ml−1 delineated conditions when ∼95% of water samples contained some type of virus. Kobuvirus was the virus most strongly related to detection of any other virus. Land use had some associations with virus/F-specific coliphage detection, but season and surface water flow were the variables that were most important for broadly delineating detection. Higher relative levels of detection of human viruses and human F-RNA coliphage were associated with higher relative degrees of upstream human land development in a catchment. IMPORTANCE This study is one of the first, to our knowledge, to evaluate relationships among F-specific coliphages and a large suite of enteric viruses in mixed-use but agriculturally dominated surface waters in Canada. This study suggested that relationships between viable F-specific coliphages and molecularly detected viruses do exist, but they are not always positive. Caution should be employed if viable F-specific coliphages are to be used as indicators of virus presence in surface waters. This study elucidates relative effects of agriculture, wildlife, and human activity on virus and F-specific coliphage detection. Seasonal and meteorological attributes play a strong role in the detection of most virus and F-specific coliphage targets.

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