Mosquito breeding status in drains of Moulvibazar municipality area, Sylhet, Bangladesh

The occurrence of pollen grains in the atmosphere markedly relates to meteorological factors. In the study we have evaluated a correlation between the concentration of pollen grains in the atmosphere of Bratislava and temperature, relative humidity and rainfall during the vegetation period of 1995 and 1997. For our analysis we have selected one representative of each phytoallergen group (trees, grasses, weeds). We have chosen the Betula genus of trees, the whole Poaceae family of grasses and ragweed Ambrosia artemisiifolia L. to represent weeds. The taxons mentioned represent the most significant allergens in Slovakia. The concentration of pollen grains has been monitored by a Lanzoni volumetric pollen trap. The data obtained, the average daily concentration in 1 m(3), have been included in the statistical analysis together with values for the average daily temperature, relative humidity and total rainfall in 24 h. The correlation between the concentration of pollen grains in the atmosphere and selected meteorological variables from daily monitoring has been studied with the help of linear regression and correlation coefficients. We have found the average daily temperature and relative humidity (less than temperature) to be significant factors influencing the occurrence of pollen grains in the atmosphere of Bratislava. The total daily rainfall does not seem to be significant from the statistical point of view.

Variability of soybean yield and seed quality depending on environmental hydrothermal factors

Recent studies have noted a worldwide increase in the occurrence of extreme-precipitation events. Here we use daily rainfall data from 1951 to 2010 of 659 meteorological stations in China and on the basis of duration days defined long duration heavy rainfall. Results indicate that: on the spatial distribution, short duration heavy rainfall shows gradually decreasing phenomenon from the southeast coastal to northwest inland in China from 1951 to 2010. And long duration heavy rainfall is concentrated in the southeast coastal areas, such as Guangdong, Guangxi and Hainan. On the temporal change, the interannual and interdecadal short and long duration heavy rainfall both show increasing trend. In precipitation contribution ratio, the proportion of total heavy rainfall amounts to total rainfall amounts and total heavy rainfall days to total rainfall days are 6.1%∼27.7% and 0.6%∼27.7% respectively from 1951 to 2010 in China. Short duration storm to occupy the dominant position that the proportion of short duration heavy rainfall amounts to total heavy rainfall amounts and short duration heavy rainfall days to total heavy rainfall days are 75.9%∼89.4% and 75.6%∼89.4% respectively in the same period. Long duration heavy rainfall occupy a secondary position that the proportion of long duration heavy rainfall amounts to total heavy rainfall amounts and short duration heavy rainfall days to total heavy rainfall days are only 10.6%∼24.1% and 10.8%∼24.4% respectively. On the trend of precipitation contribution, China’s the contribution rate of total heavy rainfall to the total rainfall show increasing trend with contribution of rainfall amounts and rainfall days trend are 2.1%/10a and 0.2%/10a respectively. The contribution rate of short duration heavy rainfall to the total heavy rainfall show increasing trend with contribution of rainfall amounts and rainfall days trend are 0.5%/10a and 0.4%/10a respectively. On the contrary, the contribution rate of long duration heavy rainfall to the total heavy rainfall show decreasing trend with contribution of rainfall amounts and rainfall days trend are -0.5%/10a and -0.4%/10a respectively. The results suggest that the precipitation in China are changing to extremely accompanied by short duration storm increased significantly.

Background : Hand, foot and mouth disease (HFMD) is a contagious disease of children, occurs primarily under five years of age, characterized by a history of brief febrile illness and a typical skin rash over hands and feet with or without sores in mouth, caused usually by Coxsackie virus[1]A16 viruses. It is mainly the disease of tropical and subtropical countries and bears a complex-relation with meteorological variables like temperature, rainfall and relative humidity, although no study has yet been done in Bangladesh to explain the complex relationship of the disease with these variables.
 Objective : This study sought to describe the occurrence of HFMD and its association with meteorological factors in Dhaka city.
 Methods : The present cross-sectional study collected data of 231 HFMD cases from the records of the daily register of Out-patient Department of Dhaka Shishu Hospital, Dhaka between January 2018 to December 2019. According to the study protocol a child was identified as having HFMD who had a history of brief febrile illness accompanied by a typical skin rash with or without mouth ulcers. Total numbers of cases treated monthly at OPD during the period were also recorded. Meteorological data were provided by Bangladesh Meteorological Department, which among others, included monthly average temperature, relative humidity and amount of rainfall. While the outcome variable was monthly number of HFMD cases, the predictive variables were average temperature, humidity and rainfall during the study period.
 Results : Majority (85.3%) children in the present study was < 5 years old. A male preponderance was observed in the series (60%) with male to female ratio being 3:2. A clustering of HFMD cases was observed to occur between June to October when monthly average temperature, total rainfall and humidity all were at their maximum compared to those found between November to April. The clustering of cases was more intense in the year 2019 than that in the year 2018. During the period average monthly temperature was 29.20C, average rainfall was 62.6% (238 mm) of the total annual precipitation and mean relative humidity was 79%. The proportion of HFMD cases out of total cases treated during the period was 2.2% in 2018 and was 4.1% in 2019, which in the dry season (November to April) was 0.4% and 0.5% in 2018 and 2019 respectively.
 Conclusions : The study concluded that majority of the HFMD cases occur under five years of age and boys are more likely to have the infection than the girls. A seasonality of HFMD occurrence is observed with a higher number of cases occurring in the monsoon season and fewer cases in the dry season.Clustering of HFMD cases occur between May to October when monthly average temperature, total rainfall and humidity all are at peak compared to those in November to April of the year.
 Northern International Medical College Journal Vol.11 (2) Jan 2020: 453-457

Background & Objective: Hand, foot and mouth disease (HFMD) is a contagious disease of children, occurs primarily under five years of age, characterized by a history of brief febrile illness and a typical skin rash over hands and feet with or without sores in mouth, caused usually by Coxsackievirus A16 viruses. It is mainly the disease of tropical and subtropical countries and bears a complex-relation with meteorological variables, like temperature, rainfall and relative humidity, although no study has yet been done in Bangladesh to explain the complex relationship of the disease with these variables. This study sought to describe the occurrence of HFMD and its association with meteorological factors in Dhaka city.
 Methods: The present cross-sectional study collected data of 231 HFMD cases from the records of the daily register of Out-patient Department of Dhaka Shisu Hospital, Dhaka between January 2018 to December 2019. According to the study protocol a child was identified as having HFMD who had a history of brief febrile illness accompanied by a typical skin rash with or without mouth ulcers. Total number of cases treated monthly at OPD during the period were also recorded. Meteorological data were provided by Bangladesh Meteorological Department, which among others, included monthly average temperature, relative humidity and amount of rainfall. While the outcome variable was monthly number of HFMD cases, the predictive variables were average temperature, humidity and rainfall during the study period.
 Result: Majority (85.3%) children in the present study was < 5 years old. A male preponderance was observed in the series (60%) with male to ratio being 3:2. A clustering of HFMD cases was observed to occur between June to October when monthly average temperature, total rainfall and humidity all were at their maximum compared to those found between November to April. The clustering of cases was more intense in the year 2019 than that in the year 2018. During the period average monthly temperature was 29.20C, average rainfall was 62.6% (238 mm) of the total annual precipitation and mean relative humidity was 79%. The proportion of HFMD cases out of total cases treated during the period was 2.2% in 2018 and was 4.1% in 2019, which in the dry season (November to April) was 0.4% and 0.5% in 2018 and 2019 respectively.
 Conclusion: The study concluded that majority of the HFMD cases occur under five years of age and boys are more likely to have the infection than the girls. A seasonality of HFMD occurrence is observed with a higher number of cases occurring in the monsoon season and fewer cases in the dry season. Clustering of HFMD cases occur between May to October when monthly average temperature, total rainfall and humidity all are at peak compared to those in November to April of the year.
 Ibrahim Card Med J 2021; 11 (1): 14-20

Trends in heavy rainfall, total rainfall and number of dry days in Australia have been analysed using daily rainfall records at 125 stations. Summer and winter halves of the year were considered separately for the period 1910–1990. The summer half-year is defined as November–April, while the winter-half is May–October. Heavy rainfall is defined as the 90th and 95th percentiles of daily rainfall in each half-year. The magnitude of trends was derived from linear regression while statistical significance was determined by Kendall-Tau and field significance tests. Increasing trends in heavy rainfall and total rainfall have occurred during the summer half-year, but only 10–20% of stations have statistically significant trends. During the winter half-year, heavy rainfall and total rainfall have also increased, except in far southwest Western Australia and inland Queensland. There has been a reduction in the number of dry days in both halves of the year, except in far southwest Western Australia and at a few stations in eastern Australia where there has been an increase in the number of dry days in the winter half-year. Changes in the number of dry days were statistically significant at over 50% of stations. Hence there are regions showing coherent increases and decreases in rainfall which may be due to systematic changes in climate during the last century. Trends were averaged over three broad regions with adequate station coverage. There has been a general decrease in dry days with an increase in total and heavy rainfall intensity in the northeast and southeast, and a decrease in total and heavy rainfall in the southwest. These rainfall changes are related to changes in other climate variables such as temperature and cloud cover in Australia. © 1998 Royal Meteorological Society

Analysis on Characteristic of Precipitation in Poyang Lake Basin from 1959 to 2008

Background & objective : Chicken pox or varicella is a disease of both tropical and temperate zones bearing a complex-relationship with climatic variables, like temperature, rainfall and relative humidity, wind velocity and so on. As no study has, by far, been conducted to relate its occurrence with these climatic variables in Bangladesh, this study was intended to explore the effect of weather conditions on the incidence of varicella in Dhaka city of Bangladesh.
 Methods: The present cross-sectional study obtained data of 172 varicella cases from the records of the daily register of Out-patient Department of Dhaka Shisu Hospital, Dhaka between January 2018 to December 2019. According to the study protocol a child was diagnosed as having varicella or chicken pox who had a history of short febrile illness accompanied by a pruritic vesicular eruption (on the face and trunk)) of the skin and mucous membranes which ultimate weeps out and crusts. Total number of cases treated monthly at Out-patient Department (OPD) during the period was also recorded. Climatic data were provided by Bangladesh Meteorological Department, which among others, included monthly average temperature, relative humidity (RH) and amount of rainfall or precipitation. While the outcome variable was monthly number of varicella cases, the predictive variables were average temperature, humidity and rainfall during the study period.
 Result: Over 70% of children were 1-10 years old with median age of the children being 5.5 years (range: < 1 month -14 years). Boys were a bit higher (54%) than the girls (46%). A seasonal pattern of chicken pox was seen with clustering of cases between mid-February to mid-April (spring season) with two peaks – one in February and another in April, when monthly average temperature, total rainfall and humidity all were at their optimum. The peak incidences of chicken pox cases during the spring both in 2018 and 2019 as correlated with climatic data of the same period, it is seen that the prevailing weather then was optimum-average temperature was 23°C, average precipitation was 20-25% of the total annual precipitation and relative humidity was around 65%.
 Conclusion: The study concluded that majority of the varicella cases occur under ten years of age and boys are a little more susceptible to have the infection than the girls. A seasonal pattern of chicken pox is clearly seen with clustering of cases between mid-February to mid-April (spring season) with two peaks when monthly average temperature, total rainfall and humidity all are optimally favorable for the multiplication of varicella zoster virus.
 Ibrahim Card Med J 2020; 10 (1&2): 11-17

The South West of Western Australia (SWWA) has been of interest to research due to the decrease in rainfall over this region since the 1950s with a significant shift since the 1970s. SWWA depends on the winter rainfall for meeting its agricultural water requirements and town water supply. A decrease in rainfall has adverse impacts on these sectors. The decreasing trend has been attributed to the decrease in the magnitude and frequency of the westerlies which bring rainfall to this region and the major changes in the large-scale atmospheric phenomenon such as the Southern Annular Mode. The observed decline in water levels in the dams of this region indicates a decrease in runoff which is mostly a result of decrease in heavy rainfall. This suggests to the need to characterize the rainfall changes in SWWA both temporally and spatially. Total rainfall can be decomposed into light, medium and heavy rainfalls, and the land responds differently to these rainfall classes. The light and medium rainfall is crucial in replenishing the soil moisture which is beneficial to vegetation. While heavy rainfall contributes mostly to runoff flowing into dams, it also poses a higher risk of soil erosion compared to light and medium rainfall. This study aims to quantify contributions from these rainfall classes to the decrease and interannual variations in rainfall, and to relate the decrease to station characteristics, i.e., latitude, elevation and the mean annual rainfall, and to the largescale circulation pattern known as the Southern Annular Mode (SAM). The Southern Annular Mode (SAM) is the north south movement of the westerlies which are winds from west to east and occur in the midlatitudes between the 30˚ and 60˚ in the northern and southern hemispheres. Long-term data for 30 stations were used, and daily rainfall was divided into three classes in such a way that they contributed equally (one third of the total) to the total rainfall of each station. It was observed that the decrease in heavy rainfall was mainly responsible for the decrease in total rainfall, followed by the medium and light rainfalls. Stations with a higher rainfall along the coast were more likely to experience a decrease in rainfall than those in the drier inland areas. Stations, where rainfall was strongly correlated with SAM, were mostly concentrated along the west coast of SWWA and the SAM index explained 9% of the variation in heavy rainfall and 11% in total rainfall for the region. Rainfall volume is a crucial aspect because the precipitation over an area such as a catchment largely determines water resources availability for that area. Changes in the rainfall volume have considerable implications for regional water resources planning and management. As the rainfall volume is the product of the wet area, which is the area receiving rainfall and the rainfall depth, the change in rainfall volume is the result of change in rainfall depth or that in wet area or both. No study has yet been undertaken to examine the change in rainfall volume in SWWA. This study also aims to examine the spatial and temporal changes in rainfall volume and to attribute this change to that in the wet area and that in the average rainfall depth in SWWA. Gridded daily rainfall data at 0.05° resolution for the period from 1911 to 2018 were used for an area of 265,952 km2 in SWWA. The results showed that regions near the coast with mean annual rainfall ≥ 600 mm showed significant decreasing trends in rainfall volume, and 84% of which could be attributed to a decrease in the wet area, while the decrease in rainfall depth only played a minor role. The regions farther inland showed an increasing trend in rainfall volume although the trend was not statistically significant. The regions near the coast also showed a decreasing trend in wet area with a higher number of rain days while the regions farther inland showed an increasing trend in wet area with a lower number of rain days. In the coast, the rate of decrease in rainfall has been reduced, and heavy rainfall, in fact, has increased over past 30 years, although, there was no concurrent change in SAM. The runoff in SWWA has been steadily decreasing which has led to reduction in the water available for water supply and agriculture. The study aimed to understand the role of rainfall changes in the decrease of runoff in the study area. Daily rainfall, potential evapotranspiration and runoff data for 10 catchments in SWWA were used. It was observed that all catchments exhibited a decreasing trend in runoff while the rainfall showed an increasing trend in some catchments. Further, the rate of change in runoff was found to be 2.6 times the rate of change in rainfall. The AWBM model overpredicted the runoff suggesting the presence of factors besides the decreasing rainfall in the observed decrease in runoff. The results indicated that the decrease in rainfall has led to a persistent decrease in groundwater table, which accelerated the decrease in streamflow in the region. This study focused on the trend in rainfall of different intensities and their contribution to the total rainfall trend. It was found that the decreasing trend was mainly concentrated along the coastal region (high mean annual rainfall) while the inland region (low mean annual rainfall) experienced an increasing trend in rainfall. In other words, the wet regions were becoming drier and the dry regions were becoming wetter. The trend and variability in heavy rainfall was observed to be the major contributor to the variations in total rainfall. Rainfall volume along the coast also showed a significant decrease and this was mainly due to the decrease in wet area while the decrease in average daily rainfall depth only played a minor role. Although, in the long term, the rainfall shows a decreasing trend, in the recent period, the rate of decrease in the total rainfall has reduced and the heavy rainfall, in fact, has increased with no concurrent change in SAM. The decrease in runoff was not solely caused by the changes in rainfall, but the steady decline of groundwater levels in the region could also be contributing to the decreasing runoff. Although, in the recent years, the rate of decrease in rainfall has reduced, the groundwater in this region needs to first recover before we can observe any positive change in streamflow in this region.

Central equatorial Africa is deficient in long-term, ground-based measurements of rainfall; therefore, the aim of this study is to assess the accuracy of three high-resolution, satellite-based rainfall products in western Uganda for the 2001–10 period. The three products are African Rainfall Climatology, version 2 (ARC2); African Rainfall Estimation Algorithm, version 2 (RFE2); and 3B42 from the Tropical Rainfall Measuring Mission, version 7 (i.e., 3B42v7). Daily rainfall totals from six gauges were used to assess the accuracy of satellite-based rainfall estimates of rainfall days, daily rainfall totals, 10-day rainfall totals, monthly rainfall totals, and seasonal rainfall totals. The northern stations had a mean annual rainfall total of 1390 mm, while the southern stations had a mean annual rainfall total of 900 mm. 3B42v7 was the only product that did not underestimate boreal-summer rainfall at the northern stations, which had ~3 times as much rainfall during boreal summer than did the southern stations. The three products tended to overestimate rainfall days at all stations and were borderline satisfactory at identifying rainfall days at the northern stations; the products did not perform satisfactorily at the southern stations. At the northern stations, 3B42v7 performed satisfactorily at estimating monthly and seasonal rainfall totals, ARC2 was only satisfactory at estimating seasonal rainfall totals, and RFE2 did not perform satisfactorily at any time step. The satellite products performed worst at the two stations located in rain shadows, and 3B42v7 had substantial overestimates at those stations.

Meteorological factors are one of the important factors that determine maize kernel weight and grain nutritional quality. Analyzing the influence of meteorological factors before and after anthesis on maize kernel weight and nutritional quality components is of great significance for improving corn yield and quality. Therefore, five different maize hybrids and conducted continuous experiments from 2018 to 2021 were selected in this study, to explore the response of maize kernel weight and grain nutritional quality to meteorological factors in different growth periods, and to quantify the linear relationship between grain nutritional quality parameters, grain weight, and meteorological factors. The main results were as follows: the 100-grain weight reached the maximum value of 39.53 g in 2018; the contents of crude protein, total starch, and crude fat in grains reached the maximum in 2018, 2020, and 2018, respectively, which were 9.61%, 69.2%, and 5.1%. Meteorological factors significantly affected the maize grain weight (p < 0.05). Before anthesis, total sunshine duration, average temperature, relative humidity, and the accumulated temperature had strong effects on grain weight. After anthesis, average daily temperature, total rainfall, temperature difference, accumulated temperature, average daily highest temperature, and total sunshine hours had strong effects on grain weight. There was also a significant correlation between grain weight and grain nutritional quality components (p < 0.05). The multivariate polynomial equation analysis revealed that further potential for maize grain weight could be exploited by adjusting the content of each quality component of the kernels under the current test conditions. Meteorological elements can indirectly affect the 100-grain weight through their relationship with the nutritional quality of the grains, with accumulated temperature before anthesis, average temperature after anthesis, and accumulated temperature after anthesis having the greatest indirect effect on the 100-grain weight. Therefore, the effects of pre-anthesis accumulation temperature, post-anthesis average temperature, and post-anthesis accumulation temperature on the nutritional quality of the grains can be harmonized by the application of hybrids of different lengths of vegetation and by adjusting the sowing time in agricultural production. Ultimately, maize grain weight can be increased on the basis of optimizing the content of various quality components in the grains.

This paper attempts to project possible changes in the frequency of daily rainfall events late in this century for four selected river basins (i.e., Grand, Humber, Rideau, and Upper Thames) in Ontario, Canada. To achieve this goal, automated synoptic weather typing as well as cumulative logit and nonlinear regression methods was employed to develop within-weather-type daily rainfall simulation models. In addition, regression-based downscaling was applied to downscale four general circulation model (GCM) simulations to three meteorological stations (i.e., London, Ottawa, and Toronto) within the river basins for all meteorological variables (except rainfall) used in the study. Using downscaled GCM hourly climate data, discriminant function analysis was employed to allocate each future day for two windows of time (2046–65, 2081–2100) into one of the weather types. Future daily rainfall and its extremes were projected by applying within-weather-type rainfall simulation models together with downscaled future GCM climate data. A verification process of model results has been built into the whole exercise (i.e., statistical downscaling, synoptic weather typing, and daily rainfall simulation modeling) to ascertain whether the methods are stable for projection of changes in frequency of future daily rainfall events. Two independent approaches were used to project changes in frequency of daily rainfall events: method I—comparing future and historical frequencies of rainfall-related weather types, and method II—applying daily rainfall simulation models with downscaled future climate information. The increases of future daily rainfall event frequencies and seasonal rainfall totals (April–November) projected by method II are usually greater than those derived by method I. The increase in frequency of future daily heavy rainfall events greater than or equal to 25 mm, derived from both methods, is likely to be greater than that of future daily rainfall events greater than or equal to 0.2 mm: 35%–50% versus 10%–25% over the period 2081–2100 derived from method II. In addition, the return values of annual maximum 3-day accumulated rainfall totals are projected to increase by 20%–50%, 30%–55%, and 25%–60% for the periods 2001–50, 2026–75, and 2051–2100, respectively. Inter-GCM and interscenario uncertainties of future rainfall projections were quantitatively assessed. The intermodel uncertainties are similar to the interscenario uncertainties, for both method I and method II. However, the uncertainties are generally much smaller than the projection of percentage increases in the frequency of future seasonal rain days and future seasonal rainfall totals. The overall mean projected percentage increases are about 2.6 times greater than overall mean intermodel and interscenario uncertainties from method I; the corresponding projected increases from method II are 2.2–3.7 times greater than overall mean uncertainties.

Effect of precipitation on clinic-diagnosed enteric infections in children in Rwanda: an observational study

The study area is located in Al-Rutba city, Al-Anbar Governorate, western Iraq. The metrological data were collected during 1981 – 2016, and used to assess the climatic condition for the study area. The total annual rainfall was 113.3 mm and relative humidity was 47.1%, while the monthly average temperature was 20.1 °C, evaporation was 3074.3 mm, the wind speed was 2.6 m/s with a prevailing direction along the year was NW 29.2%. Data derived from the ratio of wind direction and sunshine duration was 9.2 h/day. The climate of the study area is described as an arid and relatively hot in summer, and cold with low rain in winter. During the 35 years' comparison period, the highest potential evapotranspiration value was 175.82 mm during July and August, while the lowest value was 7.758 mm in January, while the total amount was 970.612 mm. The highest value of the corrected evapotranspiration was 212.74 mm in July and the lowest value was 6.78 mm in January, while the total amount was 1072.021 mm. Water surplus was recorded in the study area was 19.849% of the total rainfall which was equivalent to 113.3 mm. The study area consisted of a thin layer (<0.1 m) of sandy soil, therefore, this thin layer was not considered. A number of key findings are presented which pertain to; the type of rainfall event, wind conditions, and the location. Hence, the value of groundwater recharge was 22.489 mm with a rate of 19.849% which represents the percentage of groundwater recharge from the total rainfall.

Determining the daily rainfall characteristics from the monthly rainfall totals in central and northeastern Thailand