scholarly journals Annual and seasonal variability of wet day frequency in West Bengal, India

MAUSAM ◽  
2021 ◽  
Vol 68 (4) ◽  
pp. 713-722
Author(s):  
S. G. PATIL ◽  
A. MAJUMDER
Keyword(s):  
Seasonal Variability ◽  
West Bengal ◽  
Winter Season ◽  
Frequency Data ◽  
Parametric Approach ◽  
Statistical Parameters ◽  
Post Monsoon ◽  
Increasing Trend ◽  
Coefficient Of Skewness ◽  
Skewness And Kurtosis

The monthly wet day frequency data of West Bengal for period 1901-2000 were analyzed to know annual and seasonal variability over decades along with annual, pre-monsoon, monsoon, post-monsoon and winter trends. The non-parametric approach (Mann-Kendall) revealed that the most of the districts shows the decreasing trend during monsoon and increasing trend during pre, post monsoon and in winter season. The changes observed in the statistical parameters (mean, SD, coefficient of skewness and kurtosis) during different decades which reflect the changing pattern of wet-day frequency in West Bengal.

scholarly journals Rainfall trend analysis and its future projection over Gangetic West Bengal (GWB) region of India during post-monsoon and winter season

2016 ◽  
Vol 8 (3) ◽  
pp. 1152-1156 ◽  
Author(s):  
Pramiti Kumar Chakraborty ◽  
Lalu Das
Keyword(s):  
Trend Analysis ◽  
West Bengal ◽  
Winter Season ◽  
Policy Formulation ◽  
Rainfall Data ◽  
Future Projection ◽  
Short Term ◽  
Winter Rainfall ◽  
Post Monsoon ◽  
Increasing Trend

Studying the variability of rainfall and its future projection during post-monsoon and winter season is important for providing the information to the farmers regarding crop planning. For evaluating rainfall scenario, long (1901-2005) and short term (1961-2005 and 1991-2005) rainfall data of nine selected IMD stations of South Bengalwas collected and subdivided into 30 year period up to 1990 and a 15 year period from 1991 to 2005. The data were subjected to trend analysis and available GCM data were compared with the observed rainfall data. The postmonsoon and winter rainfall changes during 1901-2005 were positive (except Krishnangar, -47.67 mm) and negative (except Alipore and Berhampur) respectively. During 1991-2005 all the stations recorded a positive change during post-monsoon, while reverse was true for winter. Among the different GCMs, INGV-ECHM4 estimated the postmonsoon rainfall at the best, whereas winter rainfall successfully estimated by MIROC-Hi. Future projection of both post-monsoon and winter rainfall over the region showed an increasing trend. This will help in policy formulation for water management in agriculture.

scholarly journals Evaluation of TRMM Precipitation Dataset over Himalayan Catchment: The Upper Ganga Basin, India

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 613 ◽  
Author(s):  
Anoop Shukla ◽  
Chandra Ojha ◽  
Rajendra Singh ◽  
Lalit Pal ◽  
Dafang Fu
Keyword(s):  
Spatial Distribution ◽  
Lake Victoria ◽  
Monsoon Season ◽  
Winter Season ◽  
India Meteorological Department ◽  
Statistical Parameters ◽  
Ganga Basin ◽  
Dual Nature ◽  
Post Monsoon ◽  
Trmm Precipitation

Satellite based rainfall estimation techniques have emerged as a potential alternative to ground based rainfall measurements. The Tropical Rainfall Measuring Mission (TRMM) precipitation, in particular, has been used in various climate and hydrology based studies around the world. While having wide possibilities, TRMM rainfall estimates are found to be inconsistent with the ground based rainfall measurements at various locations such as the southwest coast and Himalayan region of India, northeast parts of USA, Lake Victoria in Africa, La Plata basin in South America, etc. In this study, the applicability of TRMM estimates is evaluated over the Upper Ganga Basin (Himalayan catchment) by comparing against gauge-based India Meteorological Department (IMD) gridded precipitation records. Apart from temporal evaluation, the ability of TRMM in capturing spatial distribution is also examined using three statistical parameters namely correlation coefficient (r), mean absolute error (MAE) and relative bias (RBIAS). In the results, the dual nature of bias is evident in TRMM precipitation with rainfall magnitude falling in the range from 100 to 370 mm representing positive bias, whereas, rainfall magnitude above 400 mm, approximately, representing negative bias. The Quantile Mapping (QM) approach has been used to correct the TRMM dataset from these biases. The raw TRMM precipitation is found to be fairly correlated with IMD rainfall for post-monsoon and winter season with R2 values of 0.65 and 0.57, respectively. The R2 value of 0.41 is obtained for the monsoon season, whereas least correlation is found for the pre-monsoon season with an R2 value of 0.24. Moreover, spatial distribution of rainfall during post-monsoon and winter season is captured adequately; however, the limited efficiency of TRMM is reflected for pre-monsoon and monsoon season. Bias correction has satisfactorily enhanced the spatial distribution of rainfall obtained from TRMM for almost all the seasons except for monsoon. Overall, the corrected TRMM precipitation dataset can be used for various climate analyses and hydrological water balance based studies in the Himalayan river basins.

scholarly journals Seasonal Trend Analysis in Rainfall and Temperature for Udaipur District of Rajasthan

2019 ◽  
Vol 14 (2) ◽  
pp. 312-319
Author(s):  
Vaibhav Deoli ◽  
Saroj Rana
Keyword(s):  
Minimum Temperature ◽  
Monsoon Season ◽  
Winter Season ◽  
Daily Rainfall ◽  
Temperature Trend ◽  
Maximum Temperature ◽  
Rainfall Trend ◽  
Post Monsoon ◽  
Increasing Trend ◽  
Level Of Significance

The present study is mainly focused on to detection of changing trend in rainfall and temperature for Udaipur district situated in the Rajasthan state of India. The district situated in the western part of India which obtained less rainfall as compared with the average rainfall of India. In the present article, the approach has been tried to analysis to detect rainfall trend, maximum temperature trend and minimum temperature trend for the area. For this daily rainfall data of 39 years (1975 to 2013) add seasonally and the temperature has been calculated by averaging of daily temperature for a period of 39 years. For determining the trend the year has been shared out into four seasons like the winter season, pre-monsoon season, monsoon season and post-monsoon season. To obtained magnitude of trend San’s slope estimator test has been used and for significance in trend Mann-Kendall statistics test has been applied. The results obtained for the study show significantly decreasing rainfall trend for the season winter and season post-monsoon whereas pre-monsoon and monsoon show increasing rainfall trend. The maximum temperature of pre-monsoon and monsoon months shows a significantly increasing trend whereas, in minimum temperature, winter season and pre-monsoon season shows an increasing trend which is significant at 10% level of significance and post-monsoon shows a decreasing trend which is also significant at 10% level of significance.

scholarly journals Studies on fish diversity concerning Hydro-ecology of Kangsabasti river in Purulia district, West Bengal, India

2020 ◽  
Vol 26 (2) ◽  
Author(s):  
Manab Kumar Saha
Keyword(s):  
Fish Species ◽  
Physicochemical Parameters ◽  
West Bengal ◽  
Monsoon Season ◽  
Fish Diversity ◽  
Riverine Ecosystem ◽  
Post Monsoon ◽  
Fish Catch ◽  
Purulia District

Fish diversity depends both on various physicochemical parameters and the biological components of the riverine ecosystem. During the study period from January 2017 to December 2019 the highest fish diversity and density were observed in post-monsoon and lowest in pre-monsoon season in the Kangsabati River, Purulia District of West Bengal. Twenty five fish species, associated with 19 genera, 10 families and 5 orders have been identified. It was recorded that the Cyprinidae was the predominant family, which represented 56% of the entire fish catch.

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 Satellite-based study of physico-optical properties of aerosols over a westernmost location of Brahmaputra valley

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Jhuma Biswas 1
Keyword(s):  
Atmospheric Aerosols ◽  
Monsoon Season ◽  
Cloud Condensation Nuclei ◽  
Winter Season ◽  
Earth Observing System ◽  
Brahmaputra Valley ◽  
Increasing Trend ◽  
Long Term Trend ◽  
Term Analysis

This study examines the long term trend of the radiatively active atmospheric aerosols which can influence the Earth’s energy budget directly by scattering and absorbing radiation and indirectly by acting as cloud condensation nuclei. MODIS sensor on board the NASA Earth Observing System Terra and Aqua satellite based Aerosol Optical Depth (AOD) data are used for long term analysis of aerosols over Bongaigaon, Assam for the period August, 2002 to March, 2017. Highest AOD values are observed in pre-monsoon (March-May) season due to long range transportation as well as intense biomass burning activities especially as a part of Jhum cultivation. In general, AOD values are low in post-monsoon (October-November) season which may be due to wash out of aerosols by rain in the preceding months without enough replacement. The monthly AOD values vary from its highest value 0.949 in April, 2016 to its lowest value 0.107 in November, 2002 for the study period. From the comparison of MODIS Terra and Aqua AOD at 550 nm, it is clearly seen that generally Terra AOD at 10:30 hr is higher than the Aqua AOD at 13:30hr. A slowly increasing trend of both Aqua and Terra AOD at 550 nm is observed over the study location. The observed Ångström exponent value varies from its minimum value in monsoon season to its maximum value in winter season. With increasing AOD values, horizontal visibility decreases over Bongaigaon.

Effect of Solvent on Protonation Equilibria of L-Serine and L-Tryptophan in Ethylene Glycol-Water Mixtures

2021 ◽  
Vol 25 (7) ◽  
pp. 124-129
Author(s):  
Ch. Sudhakar ◽  
Allabakshu Shaik ◽  
M. Ramanaiah ◽  
Ch. Nageswara Rao
Keyword(s):  
Dielectric Constant ◽  
Ethylene Glycol ◽  
Protonation Constants ◽  
Statistical Parameters ◽  
Protonation Equilibria ◽  
Effect Of Solvent ◽  
R Factor ◽  
Chemical Models ◽  
Best Fit ◽  
Skewness And Kurtosis

Protonation equilibria of L-serine and L-tryptophan in varying compositions (0.0-50.0 % v/v) of ethylene glycol-water mixtures were investigated pH-metrically. Titrations were performed at 303.0 K and the ionic strength of the medium was maintained at 0.16 mol L-1 using sodium chloride. The protonation constants have been calculated with the computer program MINIQUAD 75 and are selected based on statistical parameters. The best fit chemical models of the protonation equilibria were based on crystallographic R-factor, χ2, skewness and kurtosis. The protonation constants of L-serine and L-tryptophan change linearly with increasing ethylene glycol content. This is attributed to the dielectric constant of the medium.

Dynamic financial economic fluctuation model based on non-normal distribution

2020 ◽  
pp. 1-10
Author(s):  
Li Wang
Keyword(s):  
Normal Distribution ◽  
High Frequency ◽  
Extreme Value ◽  
High Order ◽  
High Frequency Data ◽  
Order Moment ◽  
Frequency Data ◽  
High Order Moment ◽  
Model Based ◽  
Skewness And Kurtosis

This paper discusses the modeling of financial volatility under the condition of non-normal distribution. In order to solve the problem that the traditional central moment cannot estimate the thick-tailed distribution, the L-moment which is widely used in the hydrological field is introduced, and the autoregressive conditional moment model is used for static and dynamic fitting based on the generalized Pareto distribution. In order to solve the dimension disaster of multidimensional conditional skewness and kurtosis modeling, the multidimensional skewness and kurtosis model based on distribution is established, and the high-order moment model is deduced. Finally, the problems existing in the traditional investment portfolio are discussed, and on this basis, the high-order moment portfolio is further studied. The results show that the key lies in the selection of the model and the assumption of asset probability distribution. Financial risk analysis can be effective only with a large sample. High-frequency data contain more information and can provide rich data resources. The conditional generalized extreme value distribution can well describe the time-varying characteristics of scale parameters and shape parameters and capture the conditional heteroscedasticity in the high-frequency extreme value time series. Better describe the persistence and aggregation of the extreme value of high frequency data as well as the peak and thick tail characteristics of its distribution.

scholarly journals Long-Term Trends and Seasonality Detection of the Observed Flow in Yangtze River Using Mann-Kendall and Sen’s Innovative Trend Method

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1855 ◽  
Author(s):  
Ali ◽  
Kuriqi ◽  
Abubaker ◽  
Kisi
Keyword(s):  
Trend Analysis ◽  
Yangtze River ◽  
Winter Season ◽  
Trend Test ◽  
Analysis Method ◽  
Adaptation Measures ◽  
Minimum Flow ◽  
Mk Test ◽  
Innovative Trend Analysis ◽  
Increasing Trend

Trend analysis of streamflow provides practical information for better management of water resources on the eve of climate change. Thus, the objective of this study is to evaluate the presence of possible trends in the annual, seasonal, maximum, and minimum flow of Yangtze River at Cuntan and Zhutuo stations in China for the period 1980 to 2015. The assessment was carried out using the Mann–Kendall trend test, and the innovative trend analysis, while Sen’s slope is used to estimate the magnitude of the changes. The results of the study revealed that there were increasing and decreasing trends at Cuntan and Zhutuo stations in different months. The mean annual flow was found to decrease at a rate of −26.76 m3/s and −17.37 m3/s at both stations. The minimum flow was found to significantly increase at a rate of 30.57 m3/s and 16.37 m3/s, at a 95% level of confidence. Maximum annual flows showed an increasing trend in both regions of the Yangtze River. On the seasonal scale, the results showed that stations are more sensitive to seasonal flow variability suggesting a probable flooding aggravation. The winter season showed an increasing flow trend, while summer showed a decreasing trend. The spring flow was found to have an increasing trend by the Mann–Kendall test at both stations, but in the Zhutuo Station, a decreasing trend was found by way of the innovative trend analysis method. However, the autumn flow indicated a decreasing trend over the region by the Mann–Kendall (MK) test at both stations while it had an increasing trend in Cuntan by the innovative trend analysis method. The result showed nonstationary increasing and decreasing flow trends over the region. Innovative trend analysis method has the advantage of detecting the sub-trends in the flow time series because of its ability to present the results in graphical format. The results of the study indicate that decreasing trends may create water scarcity if proper adaptation measures are not taken.

scholarly journals Land Situation and Sowing Date Effects Growth and Yield of Crops in the Rice-Pulse Based Cropping Systems of Coastal India

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 152
Author(s):  
Koushik Brahmachari ◽  
Sukamal Sarkar ◽  
Donald S. Gaydon ◽  
Manoj Kumar Nanda ◽  
Argha Ghosh ◽  
...  
Keyword(s):  
West Bengal ◽  
Cropping Systems ◽  
Winter Season ◽  
Cropping System ◽  
Sowing Date ◽  
Growth And Yield ◽  
Limited Area ◽  
Pulse Crops ◽  
Stover Yield ◽  
Saline Zone

The costal saline zone of West Bengal in India is the home for millions of the world’s poorest and most vulnerable people. Due to gradual increase in salt accumulation on soils of the costal saline zone of West Bengal in India from winter to summer days, cultivation of the second crop in winter season becomes possible in a limited area. To address this issue, field experiment was conducted both in rainy and winter seasons of 2016–2017 and 2017–2018 in this zone to study the feasibility of incorporating different winter pulses (lentil and grass pea) in the rice based cropping system. The experiment was conducted in strip plot design having two factors namely, Factor I: Six dates of sowing of rice at an interval of one week (2nd week of June to 3rd week of July) and Factor II: Two land situations (Medium-upland and Medium-lowland). Date of sowing significantly influenced dry matter and macro-nutrients (NPK) partitioning in rice. Irrespective of land situation, crop sown on 1st and 2nd dates recorded significantly higher grain yield and macro-nutrient uptake by rice. Date of sowing of rice and land situation also significantly influenced the seed and stover yield of different pulse crops. Pulse crops sown on 1st and 2nd dates recorded significantly higher seed yield in coastal saline ecology of West Bengal, India.

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