scholarly journals Rainfall distribution over Bangladesh stations during the monsoon months in the absence of depressions and cyclonic storms

MAUSAM ◽  
2021 ◽  
Vol 47 (4) ◽  
pp. 339-348
Author(s):  
M. AMIRUL HUSSAIN ◽  
NAHID SULTANA

Monsoonal rainfall plays an important role in the annual rainfall distribution over Bangladesh. It is generally believed that monsoon depressions and cyclonic storms significantly affect the rainfall distribution over Bangladesh during the monsoon months and their absence causes deficient rainfall during the individual monsoon months. This aspect has been examined by computing the average rainfall for 32 meteorological observatories of Bangladesh Meteorological Department during the period 1948.91 for those monsoon months which were free from depressions and cyclonic storms. It has been found that the absence of monsoon depressions and cyclonic storms is not the main factor which causes deficient rainfall and consequent drought conditions in the individual monsoon months over different stations of the country. All the stations in the country experienced normal rainfall conditions inspite of the absence of depressions and cyclonic storms in the monsoon season (June-September).  

2013 ◽  
pp. 01
Author(s):  
João Batista Pereira Cabral ◽  
Valter Antonio Becegato ◽  
Francismário Ferreira dos Santos

The erosivity index (EI30) and its spatialization were determined for the contribution basins of the Cachoeira Dourada hydroelectric system reservoir, located between the states of Goiás and Minas Gerais and limited by coordinates 640000-760000 m W and 7910000-7975000 m N. Average monthly and annual rainfall data corresponding to eight localities and to a 30-year period were treated. It was observed that in this period the average annual rainfall was 1441 mm, the highest and lowest indexes having occurred respectively in January and July (7.5 mm). EI30 varied from 7100 to 8500 MJ mm (ha h)-1. The most representative period was October to March, corresponding to 7880.3 MJ mm (ha h)-1and 94% of the average annual EI30. The average rainfall variation coefficient for all stations was 82.73%. There is an irregular rainfall distribution in the region and consequently a non-uniform spatialization of the erosivity indexes within the influence area of the reservoir. The highest rainfall values coincide with the period of soil preparation and development of annual-cycle plants, mainly soybean and corn.


MAUSAM ◽  
2021 ◽  
Vol 61 (2) ◽  
pp. 155-162
Author(s):  
S. M. METRI ◽  
KHUSHVIR SINGH

In this paper the rainfall features at different raingauge stations of Goa state have been studied for the period of 30 years. The statistical parameters such as mean monthly rainfall, Standard Deviation and Coefficient of Variation have been computed for each raingauge station of Goa. Some heavy rainfall events during the period have also been studied. The study shows the significant rising trend of rainfall towards the eastern parts of Goa. Goa experiences an average rainfall of about 330 cm annually and around 90% of annual rainfall occurs during southwest monsoon season i.e. (June to September). Studies revealed that most of heavy rainfall events caused due to active off-shore trough and low pressure systems formed over southeast Arabian Sea. It has also come out from the study that the orography of Goa plays an important role in rainfall distribution. Valpoi receives maximum rainfall due to its orographic effect.


2021 ◽  
Vol 8 (2) ◽  
pp. 120-128
Author(s):  
PAWAN JEET ◽  
KN SINGH ◽  
RAJEEV RANJAN KUMAR ◽  
BISHAL GURANG ◽  
AK SINGH ◽  
...  

In this paper, an attempt has been made to study the temporal variation in monthly, seasonal and annual rainfall, and average annual maximum and minimum temperature for the period 1901-2015 over Ranchi district of Jharkhand, India. Long-term changes in rainfall, temperature was determined by Man-Kendall rank statistics and Sen’s slope, and forecasting of time series was determined by ARIMA model. The results revealed that there was significant decrease of average rainfall in the month of February and August while increase in month May and Pre-monsoon season. Average rainfall in the month of February, May, August and Pre-monsoon season showing insignificant increasing as well as decreasing rainfall trend. The average annual maximum and minimum temperature showing decreasing and increasing trend over Ranchi district during the period 1901 to 2015. This paper also describes five-year prediction of rainfall and temperature climatic variables.


Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 79-86 ◽  
Author(s):  
P. V. Elizar’ev ◽  
D. V. Lomaev ◽  
D. A. Chetverina ◽  
P. G. Georgiev ◽  
M. M. Erokhin

Maintenance of the individual patterns of gene expression in different cell types is required for the differentiation and development of multicellular organisms. Expression of many genes is controlled by Polycomb (PcG) and Trithorax (TrxG) group proteins that act through association with chromatin. PcG/TrxG are assembled on the DNA sequences termed PREs (Polycomb Response Elements), the activity of which can be modulated and switched from repression to activation. In this study, we analyzed the influence of transcriptional read-through on PRE activity switch mediated by the yeast activator GAL4. We show that a transcription terminator inserted between the promoter and PRE doesnt prevent switching of PRE activity from repression to activation. We demonstrate that, independently of PRE orientation, high levels of transcription fail to dislodge PcG/TrxG proteins from PRE in the absence of a terminator. Thus, transcription is not the main factor required for PRE activity switch.


2021 ◽  
Vol 331 ◽  
pp. 08006
Author(s):  
Arniza Fitri ◽  
Muhammad Shubhi Nurul Hadie ◽  
Adelia Agustina ◽  
Dian Pratiwi ◽  
Susarman ◽  
...  

Cimadur river basin is one of the most important catchment areas in Lebak District, Banten Province. For the past few years, the catchment has experienced floods during the rainy season. The big issue of flooding has been recorded recently in December 2019 which has caused damage and negative impacts to the local people and surrounding community. This study aims to analyze the possibility of flood peak discharges in the catchment area of the Cimadur river. The flood discharges are calculated for 2, 5, 10, 25, 50, and 100 years return period based on the daily rainfall data from the year 2011 to 2020. The rainfall and land use data are obtained from PT Saeba Consultant. In this study, the hydrological analyses are including 1) analyses of average annual rainfall using the Thiessen method; 2) analyses of rainfall distribution and estimation of design rainfall by considering three methods involving: Log-Normal, Log Pearson Type III, and Gumbel Type 1; and 3) analyses of flood discharges by adopting Nakayasu Synthetic Hydrograph Unit (SHU). The rainfall distribution analyses show that the Log Pearson Type III provided the best fit. Based on the flood peak discharges analyses, the results show that the flood discharges for the 5, 10, 25, and 50 years return period in the Cimadur river basin are 470.71 m3/s, 560.16 m3/s, 698 m3/s, and 820.4 m3/s, respectively.


MAUSAM ◽  
2022 ◽  
Vol 44 (3) ◽  
pp. 271-276
Author(s):  
H. N. SRIVASTAVA ◽  
K. C. SINHARAY ◽  
R. K. MUKHOPADHYAY

The study deals with the spatial and temporal variations of intra-seasonal oscillations in radio refractive index during southwest monsoon season over India and islands over Indian seas. Average daily radio refractive index data from 1 June to 30 September and that of the individual years for the period 1969-1986 were subjected to harmonic analysis to investigate the contributions of various periodicities in monsoon radio refractive index. The inter-annual variability of various intra-seasonal oscillations have been studied for each 5° latitudinal strip from 50 oN to 30° N with the help of variance explained by various frequency modes for different years. Variance explained by 30-60 day and 10-20 day modes were studied in relation to monsoon performance.   The northward and eastward propagation of30.60 day mod~ was noticed. The 10.20 day mode and seasonal mode dominate at latitudinal belts 5°N.10oN and 25°N-30°N respectively. Between 10°N and 25°N, both 30-60 day and 10-20 day modes occur.  


2018 ◽  
Vol 6 (4) ◽  
pp. 359-365
Author(s):  
Sunil Kumar Chaudhary ◽  
Santosh Marahatta ◽  
Manisha Chaudhary

The weed is a major constraint of dry-direct seeded rice (DDSR) due to change in establishment methods and shifting weed flora towards competitive grasses and sedges. To minimize the weed density, its species and dry weight with brown manuring and for optimizing the yield of DDSR, the experiment was conducted during monsoon season of 2014 at Chitwan, Nepal. The experiment was done using a strip plot design to find the optimum seed rate and killing date of Sesbania under rice-Sesbania co-culture. Among different seed rates (60, 80, 100 kg ha-1) and knocking down days (21, 28, 35 & 42 DAS) of Sesbania, the optimum seed rate of Sesbania was 102 kg ha-1 and killing date was 32 days. The individual plot size was 5 x 4 m2. The growing of Sesbania with 100 kg seeds ha-1 along with its knocked down at 28 DAS was seen best to minimize the weeds having better performance of rice. The experiment clearly demonstrated the importance of brown manuring on effective control of weeds and on grain yield of rice under dry direct seeded rice. Int. J. Appl. Sci. Biotechnol. Vol 6(4): 359-365


1982 ◽  
Vol 4 (1) ◽  
pp. 5 ◽  
Author(s):  
BD Foran ◽  
G Bastin ◽  
E Remenga ◽  
KW Hyde

Three central Australian pasture types grazed by beef cattle were exdosed for eleven years, and detailed plant measure- ments made over the last seven years. The exclosed land extended out 3.2 km from permanent watering points. Rainfall during this period (1968-1979) varied from well above average for three years to near drought conditions. The series of above average rainfall years had a @eater influence on yield, density and cover of the herbage layer than the experimental treatments of exclosure and distance from water. Dry matter production varied from 217 kg ha-1 to 2377 kg ha-1. Overall, plant density and cover were generally not affected by treatments, although some plant species and species groups were affected. Grazing should continue at present stocking levels and under similar management on the studied landscapes, as no dele terious effects have been found during the study period.


1964 ◽  
Vol 55 (3) ◽  
pp. 421-435 ◽  
Author(s):  
D. M. Minter

An account is given of seasonal changes in the incidence and relative abundance of a number of Phlebotomine sandflies which rest in termite hills in two widely separated areas of Kenya.The annual pattern of rainfall distribution is shown to be of greater importance than the total precipitation in influencing the gross distribution and local abundance of many sandflies.Kenya sandflies fall readily into ‘ perennial ’ and ‘ rainy-season ’ groups: the former have a wide distribution and appear to breed throughout the year. The distribution of the ‘ rainy-season ’ sandflies is relatively restricted, since these species are found almost exclusively in areas with a bimodal pattern of annual rainfall; it is suggested that they may survive the intervening dry periods in larval diapause. The length rather than the severity of the dry seasons is thought to be the limiting factor in the distribution of ‘ rainy-season ’ species.Examples are given of the seasonal changes in structure of populations made up of several species sharing, in the adult form, the same termite-hill habitat.


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