scholarly journals The Influence of Seasonal Water Level Fluctuations on the Soil Nutrients in a Typical Wetland Reserve in Poyang Lake, China

2021 ◽  
Vol 13 (7) ◽  
pp. 3846
Author(s):  
Shuangshuang Zhang ◽  
Jin Wei ◽  
Yiping Li ◽  
Maoqing Duan ◽  
Amechi S. Nwankwegu ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Soil Nutrients ◽  
Anthropogenic Activities ◽  
Close Association ◽  
Dry Season ◽  
Water Level Fluctuations ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Index Method ◽  
Spatio Temporal

To comprehend the distribution characteristics of the nutrients and the variations in the soil fertility, a total of 23 samples were collected from Nanjishan wetland reserve in the dry season, wet season, and water-recession season. The study area was divided into four areas (A1, A2, A3, and A4) based on the local hydrological conditions, geographical locations, and nutrient load characteristics. The findings showed that the highest concentration of nutrients appeared in A1, followed by A2 due to anthropogenic activities and the sewage discharge along Ganjiang River. Except for the total amounts of nutrients (the total nitrogen (TN), total phosphorus (TP), and total potassium (TK)), the nutrient concentrations dropped in the wet season and recovered in the water-recession season. A close association between microorganisms and the soil nutrients was observed. The Integrated Fertility Index (IFI) indicated a significant spatio-temporal variability in the soil fertility. The soil quality was higher in the dry season. The values of the IFI displayed a decreasing trend during the growing season (wet season). The single factor standard index method (SFSI) suggested that the whole area had a potential risk of eutrophication, to which the TN could be considered a main contributor.

scholarly journals Seasonal changes in water quality and macrophytes and the impact of cattle on tropical floodplain waterholes

2012 ◽  
Vol 63 (9) ◽  
pp. 788 ◽  
Author(s):  
N. E. Pettit ◽  
T. D. Jardine ◽  
S. K. Hamilton ◽  
V. Sinnamon ◽  
D. Valdez ◽  
...  
Keyword(s):  
Water Quality ◽  
Seasonal Changes ◽  
Aquatic Macrophyte ◽  
Plant Cover ◽  
Critical Role ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Dry Tropics ◽  
The Impact

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.

scholarly journals Seasonal Water Level Fluctuation and Concomitant Change of Nutrients Shift Microeukaryotic Communities in a Shallow Lake

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2317
Author(s):  
Yang Liu ◽  
Ze Ren ◽  
Xiaodong Qu ◽  
Min Zhang ◽  
Yang Yu ◽  
...  
Keyword(s):  
Water Level ◽  
Soluble Reactive Phosphorus ◽  
Dry Season ◽  
Water Level Fluctuation ◽  
Water Level Fluctuations ◽  
Rrna Gene ◽  
Level Fluctuation ◽  
Wet Season ◽  
Concomitant Change ◽  
Modular Structures

Seasonal water level fluctuations (WLFs) impose dramatic influences on lake ecosystems. The influences of WLFs have been well studied for many lake biotas but the microeukaryotic community remains one of the least-explored features. This study employed high-throughput 18S rRNA gene sequencing to investigate the spatiotemporal patterns of microeukaryotic communities in the dry and wet seasons with concomitant change of nutrients in Poyang Lake, which experiences huge seasonal WLFs. The results showed that the dry season and wet season had distinct microeukaryotic community compositions and structures. In the dry season, Ciliophora (13.86–40.98%) and Cryptomonas (3.69–18.64%) were the dominant taxa, and the relative abundance of these taxa were significant higher in the dry season than wet season. Ochrophyta (6.88–45.67%) and Chlorophyta (6.31–22.10%) was the dominant taxa of microeukaryotic communities in the wet season. The seasonal variation of microeukaryotic communities was strongly correlated to seasonal nutrient variations. Microeukaryotic communities responded significantly to dissolved organic carbon, total nitrogen, nitrate, and soluble reactive phosphorus in the dry season, and correlated to nitrate and total phosphorus in the wet season. The microeukaryotic community showed different modular structures in two seasons, and nutrient variations were the key factors influencing seasonal variations of the modular structures. Moreover, microeukaryotic community networks based on different seasons indicated that the microeukaryotic community co-occurrence patterns were not constant but varied largely associating with the nitrogen and phosphorus variations under the effects of WLFs. Our results are important for understanding how microeukaryotic communities respond to nutrient variation under seasonal water level fluctuation.

scholarly journals DETECTION OF POLYCYCLIC AROMATIC HYDROCARBONS COMPOUNDS CONCENTRATIONS AND THEIR FATE IN TIGRIS RIVER WITHIN BAGHDAD CITY - IRAQ.

2019 ◽  
Vol 50 (Special) ◽  
Author(s):  
Khalaf & et al.
Keyword(s):  
Molecular Weight ◽  
Anthropogenic Activities ◽  
Dry Season ◽  
Wet Season ◽  
Tigris River ◽  
Water And Sediment ◽  
Polycyclic Aromatic ◽  
Physical And Chemical ◽  
Chemical Water

The objective of this study was to investigate concentrations, compositions of PAHs and to study physical and chemical water characteristic in Tigris River. This study was conducted during July 2017 to April 2018. The results showed that twelve PAHs compounds were detected in water and sediment of the river and the highest concentrations of these compounds were founded in sediment samples. Concentrations of PAHs in water samples have a ranged between (0.36µg. l-1) in wet season to (0.53µg.l-1) in dry season, while the sediment sample have a ranged between (633.23µg.kg-1) in wet season to (778.28µg.kg-1) in dry season. The origin of PAHs in water and sediment were pyrogenic depending on the ratios of Phenanthene/Anthracene, Anthacene/ (Anthacene + Phenanthene), low molecular weight/high molecular weight. According of these results, it can be concluded that the Tigris River is polluted with the PAHs, and anthropogenic activities with the largest impact on the water health and quality of the river.

scholarly journals Spatial Variations in Groundwater Quality Around Dumpsite in Igando

2015 ◽  
Vol 6 (1) ◽  
pp. 179-186
Author(s):  
Akoteyon ◽  
S Isaiah
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Drinking Water ◽  
Groundwater Quality ◽  
Anthropogenic Activities ◽  
Dry Season ◽  
Spatial Variations ◽  
T Test ◽  
Drinking Water Quality ◽  
Wet Season

Water samples collected from fifteen hand dug wells in November (dry season), 2011 and July (Wet season), 2012 using random sampling technique. In situ parameters were measured for pH, electrical conductivity, total dissolved solids using portable meters. Heavy metals were analyzed for; Fe, Cu, Zn, Cd, Pb, and Cr using Atomic Absorption Spectrophotometer (AAS). The study aimed at examining the spatial variations in groundwater quality around dumpsite in Igando using paired sample T-test statistical technique. The result shows that the measured pH values were below the minimum WHO standard for drinking water quality in wet and dry seasons in about73.3% and 26.7% respectively. Also, approximately, 13.3% of EC, and 6.7% exceeded the prescribed standard limit of WHO in dry and wet seasons respectively. Concentration of Fe exceeded drinking water quality in all the sampling locations during wet season and only about 46.7% in dry season. Pb, Zn, and Cu exceeded WHO limit in about 86.7%, 80%, and 26.7% respectively in dry season. Concentration of Pb, Cd , Cu and Cr were under detection limit in all the locations except at locations G2 for Cu in wet season. The paired samples statistics and correlation revealed that the mean values of all the parameters were higher in dry season with the exception of Fe. No significant correlations exist among the paramet er for both seasons at p<0.05. The paired T-test show significant seasonal variations among four heavy metals including Fe, Cd, Pb and Zn.The study concluded that, samples in dry season are of low quality compared to wet. The study recommends public enlightenment on solid waste disposal, controlled anthropogenic activities, and treatment /recycling of waste to prevent heavy metal from leaching unto the sub-surface.DOI: http://dx.doi.org/10.3329/jesnr.v6i1.22063 J. Environ. Sci. & Natural Resources, 6(1): 179-186 2013

scholarly journals Assessment of Anions and Heavy Metals in Sediments from River Sio, Busia County, Kenya

2019 ◽  
pp. 1-18
Author(s):  
K. O. Ondoo ◽  
J. K. Kiptoo ◽  
A. O. Onditi ◽  
S. M. Shivaji ◽  
J. K. Ogilo
Keyword(s):  
Heavy Metals ◽  
Surface Runoff ◽  
Anthropogenic Activities ◽  
Contamination Factor ◽  
Water Source ◽  
Pollution Load Index ◽  
Dry Season ◽  
Wet Season ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer

Agricultural activities, discharge of raw sewage into farms and the rise in urbanization have greatly contributed to soil pollution. During the rainy season, surface runoff from farms find their way into water bodies and deposits these contaminants into Rivers and Lakes which poses a threat to both aquatic and terrestrial organisms that depend on that water source. The objective of this research was to determine the level of anions and heavy metals from sediments in River Sio, Busia County, Kenya. Five sediment samples were taken from five sampling points and the levels of anions and heavy metals in them determined. Anions were determined using Shimadzu 1800 UV/visible spectrophotometer while heavy metals were determined using Shimadzu 6200 flame atomic absorption spectrophotometer (AAS). Copper, lead and nickel were above the allowed WHO limits while cadmium was below detection limit. The levels of nitrates, phosphates and chlorides were higher during the wet season due to surface runoff that carried these nutrients from the farms and deposited them on the bottom of the River. The levels of heavy metals were high during the dry season due to evaporation of water from the River, leading to an increase in the analyte concentration during the dry season. High levels of copper and nickel in the sediments points to the use of herbicides and pesticides in farming and washing of vehicles and motorcycles on the banks of the River. According to Igeo nickel showed moderate pollution during the dry season. The contamination factor for lead was very high during the dry season, while pollution load index confirmed pollution due to anthropogenic activities in sampling sites 1 – 4 during the dry season and no pollution due to anthropogenic activities during the wet season.  The study recommends reduced use of inorganic fertilizers in order to save the River from the danger of eutrophication. Excessive use of agrochemicals such as herbicides and pesticides should be discouraged. In addition, pesticide leaching and the level of microbes in soil and sediments should be considered for further research

scholarly journals Environmental Impact of Heavy Metals from Poultry Waste Discharged into the Olosuru Stream, Ikire, Southwestern Nigeria

2019 ◽  
Vol 9 (22) ◽  
Author(s):  
Abayomi Tolulope Oyewale ◽  
Taiwo Adekanmi Adesakin ◽  
Adedeji Idowu Aduwo
Keyword(s):  
Heavy Metals ◽  
Environmental Impact ◽  
Anthropogenic Activities ◽  
Sampling Period ◽  
Dry Season ◽  
World Health ◽  
Poultry Waste ◽  
Wet Season ◽  
Southwestern Nigeria ◽  
Southwest Nigeria

Background. Water supplies can be contaminated by anthropogenic activities. The poultry industry uses a variety of heavy metals as additives in chicken feed, but excretion, runoff and dumping of heavy metals can threaten water bodies and have adverse effects on human health. Objectives. The aim of the present study was to determine the environmental impact of heavy metals from poultry waste discharged into the Olosuru stream, located in Ikire, southwest Nigeria. Methods. In order to study changes in heavy metal loads, samples were collected six times during the wet season (September, October 2014 and April 2015) and dry season (November 2014, January and February 2015). The inhabitants of Olosuru village use water for domestic and agriculture purposes from the Olosuru stream which is located only a few meters from a poultry farm discharge point. Three stations were sampled, upstream to downstream, with 500 meter distance between each point. Results. Selected heavy metals concentrations in the Olosuru stream were all above the World Health Organization (WHO) standard for drinking water. The highest mean concentrations of heavy metals were recorded at the downstream station, while arsenic, iron and lead showed significant spatial and seasonal differences. Seasonally, the highest iron concentrations were recorded in the dry season (0.104±0.401 mg/L), while the mean concentrations of other heavy metals recorded during the sampling period were higher during the wet season. Conclusions. Concentrations of heavy metals in the present study were above acceptable limits. Poultry waste discharged into the Olosuru stream, can have negative impacts on the stream and health implications for local residents. Competing Interests. The authors declare no competing financial interests.

scholarly journals Pemetaan Indek Kekeringan dan Sebaran Titik Hotspot Daerah Potensi Kebakaran Hutan dan Lahan di Propinsi Riau

2018 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Yotta Autika ◽  
Aras Mulyadi ◽  
Yusni Ikhwan Siregar
Keyword(s):  
Land Use ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Dry Season ◽  
Wet Season ◽  
Index Method ◽  
Spi Index ◽  
Maximum Duration ◽  
Relationship Of ◽  
The Relationship

Riau is one of the most vulnerable provinces to forest and land fires in Indonesia. The potency for forest and land fires is inseparable from the presence of peatlands and exacerbated by drought. The purpose of this research is to know the characteristics of meteorological drought using SPI (Standardized Precipitation Index) method and its relation with forest and peatland fire as one of disaster management effort in Riau Province. The data used in this research are monthly rainfall data from meteorology station and rainfall posts of BMKG, hotspot data from NOAA satellite, map of Forest Use Agreement (TGHK), peat land map and land use map. Analysis of drought characteristics was done by calculating monthly SPI-1 then determining the maximum duration, intensity, severity and drought exposure. Determination of the severity of the drought by weighting and suspension method was based on duration and intensity while drought exposure was done by overlaying the map of the severity of the drought with the land use map. Meanwhile, to know the potential of forest and land fires began with the selection of hotspots on peatlands and forest areas every month then created a graph of the relationship of meteorological drought with the number of hotspots. Then, to see the relationship of drought distribution to the distribution of hotspots in dry season (MK) and wet season (MH) of 2015 was done by overlaying cover the drought distribution with hotspot distribution. The result shows that drought characteristic in the most of Riau province has maximum duration around 4-6 months, dry category of intensity, high category of severity with exposure area in paddy field, field, habitation, and plantation. Then, negative SPI Index (dry condition) has potential to increase the number of hotspots otherwise positive SPI index (wet condition) leads to low occurrence of hotspot. The drought distribution in the dry season (July, August, September) of 2015 triggers the number of hotspots during drought conditions, while in wet season (April, November, December) of 2015 are dominated by normal conditions, some areas are dry and wet, resulting in lower hotspots distribution compared to the dry season.

scholarly journals Submarine Groundwater Discharge in a Coastal Bay: Evidence from Radon Investigations

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2552
Author(s):  
Manhua Luo ◽  
Yan Zhang ◽  
Hailong Li ◽  
Xuejing Wang ◽  
Kai Xiao
Keyword(s):  
Submarine Groundwater Discharge ◽  
Anthropogenic Activities ◽  
Jiaozhou Bay ◽  
Groundwater Discharge ◽  
Dry Season ◽  
Balance Model ◽  
Wet Season ◽  
Discharge Rates ◽  
Submarine Groundwater ◽  
Coastal Bay

Jiaozhou Bay, an urbanized coastal bay located in the southern part of Shandong Peninsula, China, has been deeply affected by anthropogenic activities. Here, the naturally occurring 222Rn isotope was used as a tracer to assess the submarine groundwater discharge (SGD) in this bay. The time series of 222Rn concentrations in nearshore seawater were monitored continuously over several tidal cycles at two fixed sites (Tuandao (TD) and Hongdao (HD)) during the dry season in spring and the wet season in autumn of 2016. 222Rn concentrations in seawater were negatively related to the water depth, indicating the influence of tidal pumping. A 222Rn mass balance model revealed that the mean SGD rates were 21.9 cm/d at TD and 17.8 cm/d at HD in the dry season, and were 19.5 cm/d at TD and 26.9 cm/d at HD in the wet season. These rates were about 8–14 times the discharge rates of the local rivers. Enhanced groundwater inputs occurred at HD in the wet season, likely due to the large tidal amplitudes and the rapid response to local precipitation. Large inputs of SGD may have important influences on nutrients levels and structure, as well as the water eutrophication occurring in coastal waters.

scholarly journals Environmental Dominance and Potential Impacts of Endocrine Disruptors On the Surficial Sediments of Calabar River, South Eastern Nigeria

2020 ◽  
Vol 3 (3) ◽  
Keyword(s):  
Contaminated Soils ◽  
Surface Sediments ◽  
Polychlorinated Biphenyl ◽  
Anthropogenic Activities ◽  
River Sediments ◽  
Endocrine Disrupting Chemicals ◽  
Dry Season ◽  
Point Sources ◽  
Wet Season ◽  
Surficial Sediments

Endocrine disrupting chemicals (EDCs) are persistent toxic organic and inorganic chemicals that enter the aquatic environment through point and non-point sources and alter the physico chemical nature of water and the physiology of aquatic organisms. Of significance are the organochlorine pesticides (OCPs) and the polychlorinated biphenyl (PCBs) contamination of aquatic ecosystems. The study was conducted to provide baseline data and information on the extent of surface sediments contamination by the EDCs in the Calabar river, Nigeria. Surficial sediments from five in equidistant locations were sampled using the Van Veen sediment sampler in the dry and wet seasons of 2014 and 2015. The TOC in the surface sediments for the dry and wet seasons were 33.84 ±0.21 and 54.44±0.14 % respectively. The EDCs were highest during the wet season than the dry season suggesting the desorption and re-mobilization of organochlorines from contaminated soils into the riverine system. The ∑OCP residues ranged from 12.93±0.06µg/kg dry wt in the dry season to 23.50±0.01µg/kg dry wt in the wet season. The ∑PCB concentrations, 4.02± 0.2µg/kg dry wt (dry season) and 7.26± 0.11µg/kg dry wt (wet season) were however lower than the OCPs during the study period. Most of the EDC values were above the permissible limits and maximum contaminant levels of USEPA, indicating that the Calabar river sediments are potentially contaminated as a result of anthropogenic activities entering the system. The implications of the observed seasonal trend with respect to contamination of sea foods and posing of ecological risks to humans are discussed. This study forms part of the ongoing environmental assessment of the pollution status of Nigeria’s marine and coastal ecosystems.

Importance of predation and viral lysis for bacterial mortality in a tropical western Indian coral-reef ecosystem (Toliara, Madagascar)

2015 ◽  
Vol 66 (11) ◽  
pp. 1009 ◽  
Author(s):  
M. Bouvy ◽  
P. Got ◽  
Y. Bettarel ◽  
T. Bouvier ◽  
C. Carré ◽  
...  
Keyword(s):  
Bacterial Growth ◽  
Growth Rates ◽  
Free Water ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Viral Lysis ◽  
Bacterial Mortality ◽  
Heterotrophic Nanoflagellate ◽  
Bacterial Growth Rates

Size fractionation was performed using water from the Great Reef of Toliara (Madagascar) taken from two different habitats (ocean and lagoon) during the dry and wet seasons, to study the growth and mortality rates of bacterioplankton. Experiments were conducted with 1 and 100% of heterotrophic nanoflagellate (HNF) concentrations and virus-free water was obtained by tangential filtration (10kDa). During the dry season, in both environments, bacterial abundance and production were significantly lower than values recorded during the wet season. Bacterial growth rates without grazers were 0.88 day–1 in the lagoon and 0.58 day–1 in the ocean. However, growth rates were statistically higher without grazers and viruses (1.58 day–1 and 1.27 day–1). An estimate of virus-induced bacterial mortality revealed the important role played by viruses in the lagoon (0.70 day–1) and the ocean (0.69 day–1). During the wet season, bacterial growth rates without grazers were significantly higher in both environments than were values obtained in the dry season. However, the bacterial growth rates were paradoxally lower in the absence of viruses than with viruses in both environments. Our results suggest that changes in nutrient concentrations can play an important role in the balance between viral lysis and HNF grazing in the bacterial mortality. However, virus-mediated bacterial mortality is likely to act simultaneously with nanoflagellates pressure in their effects on bacterial communities.

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