scholarly journals Reservoir’s Impact on the Water Chemistry of the Teesta River Mountain Course (Darjeeling Himalaya)

2018 ◽  
Vol 25 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Łukasz Wiejaczka ◽  
Paweł Prokop ◽  
Rafał Kozłowski ◽  
Subir Sarkar
Keyword(s):  
Heavy Metals ◽  
Environmental Factors ◽  
Physicochemical Properties ◽  
Water Chemistry ◽  
Monsoon Season ◽  
Field Research ◽  
Post Monsoon ◽  
Darjeeling Himalaya ◽  
Post Monsoon Season

Abstract The article presents the role of the newly built reservoir in the formation of the hydrochemistry of water of the Teesta River (a tributary of the Brahmaputra) in its Himalayan course. Field research were performed in the post-monsoon season of the period 2013-2015. Sampling and measuring points were located in five points over 43 km of the Teesta River in the Darjeeling Himalaya. Analysis of water along of river longitudinal profile above and below the reservoir suggest that the reservoir caused decrease most of the basic ions concentrations (Cl−, K+, Na+, Mg2+, NO3− and PO43−). An inverse trend was observed only with respect to Ca2+, SO42− and NH4+. The dam does not influent on the F− concentration. The reservoir causes minor enrichment most of the heavy metals such Cu, Ni, Zn, Cr, Cd and Sr. The lower enrichment of Teesta water below the dam indicates the water self-purification processes for metals by the Teesta Reservoir. The changes of physicochemical properties and concentrations of ions caused by the reservoir are usually normalised by environmental factors before the Teesta River outlet from the Himalayas (within 15 km of the river).

Heavy metal pollution assessment and its indexing approach for drinking water around inactive mine sites, Southwestern region of Cuddapah Basin, South India.

2021 ◽  
Author(s):  
Sudharshan Reddy Yenugu ◽  
Sunitha Vangala ◽  
Suvarna Badri
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Ecological Risk ◽  
Metal Pollution ◽  
Monsoon Season ◽  
Pollution Index ◽  
Cuddapah Basin ◽  
Post Monsoon ◽  
Groundwater Samples ◽  
Post Monsoon Season

Abstract Hazardous compounds in aquifers, especially potentially toxic heavy metals, are a major environmental and socioeconomic problem around the world. Hence, the study is intense to quantify, for the first time, the pollution status and ecological risk of heavy metals around inactive mining sites in the Southwestern (SW) region of Cuddapah Basin. Ten heavy metals, including arsenic (As), cobalt (Co), cadmium (Cd), iron (Fe), chromium (Cr), nickel (Ni), manganese (Mn), lead (Pb), zinc (Zn) and strontium (Sr) were investigated for a total of 50 groundwater samples of this study. The findings of the study revealed that arsenic (0-60.5 and o.56.3 µg/L), cadmium (0-28.1 and 0.31.1 µg/L), nickel (0-110.2 and 0–99 µg/L)), lead (0-175.6 and 0-92.3), Strontium (0-1150 and 0-1440 µg/L) concentrations are above the acceptable levels in both pre and post – monsoon seasons. The Heavy Metal Pollution Index (HPI), Heavy Metal Evolution Index (HEI) and Degree of contamination (DOC) are applied to assess hazardous metal pollution in drinking water of this area. According to HPI values 17.5 % and 10% of samples fall under high pollution index; as per the classes of HEI, 95 % and 100% of samples fall under low pollution class during the pre and post-monsoon season. According to DOC, all groundwater samples fall in a low zone. As per ecological risk classification, 90% of the samples cause extreme high ecological risk in pre & post-monsoon season in the study area.

Seasonality of butterflies in Alagar Hills reserve forest, India

ENTOMON ◽  
2020 ◽  
Vol 45 (1) ◽  
pp. 53-60
Author(s):  
Joy Sharmila E ◽  
Thatheyus A J ◽  
Susaritha S ◽  
Snegapriya M
Keyword(s):  
Environmental Factors ◽  
Negative Correlation ◽  
Monsoon Season ◽  
Dry Season ◽  
Seasonal Prevalence ◽  
Summer Period ◽  
Positive Correlation ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
Reserve Forest

Seasonal prevalence of butterflies carried out in Alagar hills reserve revealed more number of butterflies in the summer with higher density of Nymphalid butterflies followed by Papilionidae. Hesperiidae species were more in post monsoon season than in rainy or dry season. On comparing the prevalence of butterflies with environmental factors, Hesperiidae exhibited a positive correlation with rainfall, humidity and negative correlation with temperature whereas Nymphalidae and Papilionidae showed a positive correlation with temperature and negative correlation with humidity. Study showed that summer period is a suitable period for butterfly prevalence in Alagar Hills.

scholarly journals EI- Nino and tropical storm tracks over Bay of Bengal during post monsoon season

MAUSAM ◽  
2021 ◽  
Vol 42 (3) ◽  
pp. 257-260
Author(s):  
AKHILESH GUPTA ◽  
A. MUTHUCHAMI
Keyword(s):  
Tropical Cyclones ◽  
Bay Of Bengal ◽  
Tamil Nadu ◽  
Andhra Pradesh ◽  
Southern Oscillation ◽  
Monsoon Season ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
Cent Level

The role of EI-Nino in modulating tropical cyclone motion over Bay of Bengal during post monsoon season has been examined. Storms which formed during the years 1901-1987 have been classified into recuriving or those of which crossing north of 17° N and non-recurving or those of which crossing south of 17° N the east coast of India. It has been found that in most of the cases (87 %) during EI-Nino years, the tropical cyclones which formed over Bay of Bengal crossed south of 17° N, i.e. south Andhra Pradesh Tamil Nadu coast, whereas tropical cyclones, ed during the year prior to the EI-Nino years [El- Nino (-1 ) year] are seen crossing mostly (in 79% of cases) either h of 17°N or recurving m northeastward direction. In other years this kind of behaviour is not generally onseerved. The correlation between southern oscillation indices and the fractional values of storms crossing south of 170 N for the period 1901-1987 (n=87) is found to be ---0.63 which is significant at 1 per cent level.

scholarly journals Mechanisms controlling major ion chemistry and its suitability for irrigation of Narmada River, India

2021 ◽  
Author(s):  
Deepak Gupta ◽  
Sandeep Kaushik ◽  
Reetika Shukla ◽  
Virendra Kumar Mishra
Keyword(s):  
Surface Water ◽  
Water Chemistry ◽  
Monsoon Season ◽  
Sodium Absorption ◽  
Physical Parameters ◽  
Ion Chemistry ◽  
Surface Water Chemistry ◽  
Post Monsoon ◽  
Narmada River ◽  
Post Monsoon Season

Abstract Surface water chemistry of the upper Narmada River was investigated at 13 different locations for 4 consecutive years (2017 to 2020) during pre- and post-monsoon seasons. The main objective of the study was to identify the processes governing the water chemistry of Narmada River and evaluate its suitability for irrigation. The physical parameters estimated were; pH (7.9 ± 0.4 for pre- and 8 ± 0.4 for post-monsoon seasons), EC (322.8±93.3 μS/cm for pre- and 312.1±80.2 μS/cm for post-monsoon) and TDS (203.4±41.5 mg/L for pre-and 213.4±48 mg/L for post-monsoon). The obtained concentration of cations and anions were in the order of Ca++ > Na+ > Mg++> K+ and HCO3−> Cl−>SO4−> NO3−> PO4− respectively. Thus, the water of Narmada was found to be alkaline in nature. Piper diagram inferred that the water was dominated by Ca-Mg-HCO3− type of hydrochemical faces. Gibb's plot clarified that rock-water interaction regulates the ion chemistry of the Narmada. Various indices like sodium percentage (Na%), sodium absorption ration (SAR), Kelly index (Ki), permeability index (PI), magnesium hazard (MH) was calculated which showed that the surface water was suitable for irrigation. Lastly, one-way ANOVA (p < 0.05) confirmed no significant differences in water quality except for temperature, EC and SO4−, for pre- and post-monsoon season.

scholarly journals Assessment of Trophic Responses of a Reservoir to Seasonal and Annual Variations in Monsoon

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2117
Author(s):  
Su-mi Kim ◽  
Hyun-su Kim
Keyword(s):  
Water Quality ◽  
Trophic State ◽  
Monsoon Season ◽  
Phytoplankton Growth ◽  
Phosphorus Loading ◽  
Nutrient Concentrations ◽  
Trophic State Index ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
State Index

The variations in water quality parameters and trophic status of a multipurpose reservoir in response to changing intensity of monsoon rain was investigated by applying a trophic state index deviation (TSID) analysis and an empirical regression model to the data collected in two periods from 2014 to 2017. The reservoir in general maintained mesotrophic conditions, and Carlson’s trophic state index (TSIc) was affected most by TSITP. Nutrient concentrations, particularly phosphorus, did not show strong correlations with precipitation, particularly in the period with weak monsoon, and a significant increase in total phosphorus (TP) was observed in Spring 2015, indicating the possibility of internal phosphorus loading under decreased depth and stability of water body due to a lack of precipitation. TSIChl was higher than TSISD in most data in period 1 when a negligible increase in precipitation was observed in the monsoon season while a significant fraction in period 2 showed the opposite trend. Phytoplankton growth was not limited by nutrient limitation although nutrient ratios (N/P) of most samples were significantly higher than 20, indicating phosphorus-limited condition. TSID and regression analysis indicated that phytoplankton growth was limited by zooplankton grazing in the Spring, and that cell concentrations and community structure in the monsoon and post-monsoon season were controlled by the changing intensity of the monsoon, as evidenced by the positive and negative relationships between community size and cyanobacterial population with the amount of precipitation in the Summer, respectively. The possibility of contribution from internal loading and an increase in cyanobacterial population associated with weak monsoon, in addition to potential for nutrient enrichment in the post-monsoon season, implies a need for the application of more stringent water quality management in the reservoir that can handle all potential scenarios of eutrophication.

A Study on Prevalence and Seasonal Distribution of Dengue at a Tertiary Care Centre of North India

Healthline ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 100-107
Author(s):  
Arti Agrawal ◽  
Vikas Kumar ◽  
Sanjeev Kumar ◽  
Neha K Mani
Keyword(s):  
Monsoon Season ◽  
Dengue Infection ◽  
Tertiary Care ◽  
Seasonal Distribution ◽  
North India ◽  
Care Centre ◽  
Tertiary Care Centre ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
Male Preponderance

Introduction: Dengue virus infection is a major public health issue prevalent in tropical and sub-tropical countries all over the world mostly in urban and semi-urban areas. WHO estimates about 50-100 million dengue infections worldwide every year. The present study is aimed to assess the prevalence and seasonal distribution of dengue disease during three consecutive years from 2016-2018 at a tertiary care centre of North India. Method: This is an observational retrospective study conducted on total 6,481 clinical suspected cases referred from indoor and outdoor departments of Medicine and Pediatrics of one of the medical colleges of Agra during the period from 1st January 2016 to 31st December 2018. Results: The maximum positivity was recorded in the year 2016 (16.66%), followed by 2017 (14.07%) and 2018(13.56%).Our study shows male preponderance with maximum cases in the year 2018 was recorded in the month of October (22.75%) whereas the lowest in the month of May (1.96%). Most of the cases were in the age group 0-30 years with a male preponderance. The outbreak occurred during the months of August to November indicating vector transmission in the monsoon and post-monsoon season. Conclusion: From the analysis, this study reflects that the numbers of dengue cases in 2016 were maximum and outnumbered the dengue cases among three consecutive years from 2016 to 2018. The peak in dengue positivity was observed during September to October. As this disease affects the population in the monsoon and post monsoon months therefore continuous monitoring of dengue infection is important during the post-monsoon season.

scholarly journals Seasonal Nature and Trends of Tropical Cyclone Frequency and Intensity over the North Indian Ocean

2020 ◽  
Vol 15 (3) ◽  
pp. 526-534
Author(s):  
Abhisek Pal ◽  
Soumendu Chatterjee
Keyword(s):  
Time Series ◽  
Tropical Cyclone ◽  
Indian Ocean ◽  
Monsoon Season ◽  
North Indian Ocean ◽  
Post Monsoon ◽  
The North ◽  
Increasing Trend ◽  
Post Monsoon Season ◽  
Cyclone Frequency

Tropical cyclone (TC) genesis over the North Indian Ocean (NIO) region showed significant amount of both spatial and temporal variability.It was observed that the TC genesis was significantly suppressed during the monsoon (June-September) compared to pre-monsoon (March-May) and post-monsoon (October-December) season specifically in terms of severe cyclonic storms (SCS) frequency. The Bay of Bengal (BoB) was characterized by higher TC frequency but lower intensity compared to the Arabian Sea (AS). It was also observed that the TC genesis locations were shifted significantly seasonally.The movement of the TCs also portrayed some significant seasonal differences. The pre-monsoon and post-monsoon season was responsible for generating TCs with higher values of accumulated cyclone energy (ACE) compared to the monsoon. The time series of TC frequency showed a statistically significant decreasing trend whereas the time series of ACE showed astatistically significant increasing trend over the NIO.

scholarly journals Dragonflies and damselflies (Insecta: Odonata) of the Kole Wetlands, central Kerala, India

2021 ◽  
Vol 13 (3) ◽  
pp. 17963-17971
Author(s):  
A. Vivek Chandran ◽  
Subin K. Jose ◽  
Sujith V. Gopalan
Keyword(s):  
Species Richness ◽  
Monsoon Season ◽  
Survey Method ◽  
Ramsar Site ◽  
Post Monsoon ◽  
Post Monsoon Season

A year-long study was conducted at the Kole Wetlands, a Ramsar site in central Kerala to document the diversity of dragonflies and damselflies and understand their seasonality.  Checklist survey method was used to sample adult odonates in 30 randomly chosen locations.  A total of 44 species (30 dragonflies and 14 damselflies) belonging to 33 genera and eight families were recorded in the study area.  Species richness showed a peak in the post-monsoon season and a dip in the summer.  The observations support the value of the Kole Wetlands in providing valuable resources for Odonata.

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