Trend Analysis of Rainfall Data in Divisional Meteorological Stations of Bangladesh

2020 ◽  
Vol 23 (1) ◽  
pp. 49-61
Author(s):  
M Noorunnahar ◽  
MA Hossain
Keyword(s):  
Trend Analysis ◽  
Statistical Tests ◽  
Statistical Significance ◽  
Kendall Test ◽  
Monthly Rainfall ◽  
Rainfall Data ◽  
Total Rainfall ◽  
Annual Total ◽  
Level Of Significance ◽  
Non Parametric

Sixty four years, 1952-2016, rainfall data (monthly rainfall and annual total rainfall) were analyzed using non-parametric methods like Mann-Kendall and Sen’s T test to detect the recent trends in rainfall pattern over seven divisions of Bangladesh. Sen’s non-parametric estimator of slope was frequently used to estimate the magnitude of trend, whose statistical significance was assessed by the Mann–Kendall test. Station basis trend analysis was performed for rainfall data. For rainfall of Bangladesh most of the stations, viz. Dhaka, Sylhet, Rangpur, Khulna showed significant upward trend. There were rising rates of rainfall in some months such as April in Rangpur and September in Khulna and a decreasing trend in some other months as in January in Sylhet were obtained by these statistical tests suggested overall significant changes in rainfall trend in these areas. Monthly rainfall and annual total rainfall were found to decrease at the rates of 4.94 mm/year and 16.11 mm/year, respectively, where the downward trend of monthly total rainfall was insignificant but the trend of annual total rainfall was significant with 5% level of significance. Ann. Bangladesh Agric. (2019) 23(1) : 49-61

scholarly journals Time Series Analysis of Temperature and Rainfall Data of Dhaka Division

2017 ◽  
Vol 65 (2) ◽  
pp. 119-123
Author(s):  
Khadija Khatun ◽  
MA Samad ◽  
Md Bazlur Rashid
Keyword(s):  
Climatic Factors ◽  
Statistical Significance ◽  
Rainfall Data ◽  
Maximum Temperature ◽  
Total Rainfall ◽  
Annual Average ◽  
Mean Temperature ◽  
Average Maximum ◽  
Annual Total ◽  
Level Of Significance

In this paper, thirty five years’ (1981-2015) temperature and rainfall data have been studied to detect the recent trends in temperature and rainfall over Dhaka division of Bangladesh. Data of climatic factors such as annual average maximum temperature (MAXT), minimum temperature (MINT), mean temperature (MEANT), monsoon total rainfall (MTR) and annual total rainfall (ATR) have been analyzed. Sen’s non-parametric estimator of slope has been frequently used to estimate the magnitude of trend, whose statistical significance is assessed by the Mann–Kendall test. For this purpose, data from four meteorological stations (Dhaka, Mymensingh, Tangail and Faridpur) have been used. It is observed that annual average maximum, minimum and mean temperature of the study area are increasing at the rates 0.0170C/year, 0.0090C/year and 0.0130C/year respectively and the upward trend is statistically stable with 10% level of significance. On the other hand, monsoon total rainfall and annual total rainfall are decreasing at the rates of 4.94 mm/year and 16.11mm/year respectively where the downward trend of MTR is insignificant but the trend of ATR is significant with 10% level of significance. Dhaka Univ. J. Sci. 65(2): 119-123, 2017 (July)

scholarly journals Statistical analysis of long-term rainfall trends in Cherrapunji, Meghalaya, India

2021 ◽  
Vol 13 (1) ◽  
pp. 170-177
Author(s):  
Surobhi Deka
Keyword(s):  
Trend Analysis ◽  
Water Resource Management ◽  
Kendall Test ◽  
Monthly Rainfall ◽  
Change Scenario ◽  
Rainfall Trend ◽  
Large Variability ◽  
Rainfall Trends ◽  
Test Of Significance ◽  
Level Of Significance

Rainfall is the key climatic variable that governs the regional hydrologic cycle and availability of water resources. Rainfall trend analysis in a localized watershed can improve many aspects of water resource management not only to the catchment itself but also to some of the related other catchments. The trend analysis of monthly rainfall data over Cherrapunji of Meghalaya in India for the period 1872-2007 has been carried out in this work. While the magnitude of the trend in the time series has been determined using Sen's estimator, the significance of the trend in monthly rainfall series has been tested using Mann-Kendall test. During the time span 1872-2007, an increasing trend has been found in the monthly rainfall for the months July, October and November, and a decreasing trend has been found in the monthly rainfall for the months February to June, August and September. On the other hand, it was found that none of Mann-Kendall Z values was significant at 5% level of significance. Therefore, from Mann-Kendall Z test, it can be concluded that there is no trend in any month in monthly rainfall for the station Cherrapunji. For the better assessment of the temporal variation in monthly rainfall trend, whole period was divided into two halves, 1872-1939 and 1940-2007. Then, trend magnitude through Sen's estimator and Mann-Kendall Z for test of significance were determined for these two time periods separately. The analysis of trends of monthly rainfall in these two halves showed large variability in the magnitude and direction of the trend in various months from one half to another. Accurate prediction of trends in monthly rainfall is an important aspect of climate research and we believe that present study could provide a scope to correlate between current rainfall trend and climate change scenario of the study area.

Homogeneity Evaluation of Historical Rainfall and Temperature Series in Mato Grosso

2019 ◽  
pp. 1-7
Author(s):  
Elizangela Selma da Silva ◽  
José Holanda Campelo Júnior ◽  
Francisco De Almeida Lobo ◽  
Ricardo Santos Silva Amorim
Keyword(s):  
Trend Analysis ◽  
Minimum Temperature ◽  
Statistical Tests ◽  
Kendall Test ◽  
Maximum Temperature ◽  
Data Series ◽  
Positive Trend ◽  
Mato Grosso ◽  
Temperature Climate ◽  
Precipitation And Temperature

The homogeneity investigation of a series can be performed through several nonparametric statistical tests, which serve to detect artificial changes or non-homogeneities in climatic variables. The objective of this work was to evaluate two methodologies to verify the homogeneity of the historical climatological series of precipitation and temperature in Mato Grosso state. The series homogeneity evaluation was performed using the following non-parametric tests: Wald-Wolfowitz (for series with one or no interruption), Kruskal-Wallis (for series with two or more interruptions), and Mann-Kendall (for time series trend analysis). The results of the precipitation series homogeneity analysis from the National Waters Agency stations, analyzed by the Kruskal-Wallis and Wald-Wolfowitz tests, presented 61.54% of homogeneous stations, being well distributed throughout Mato Grosso state, whereas those of the trend analysis allowed to identify that 87.57% of the rainfall-gauging stations showed a concentrated positive trend, mainly in the rainy season. Out of the conventional stations of the National Institute of Meteorology of Mato Grosso, seven were homogeneous for the precipitation variable, five for maximum temperature and four stations were homogeneous for minimum temperature. For the trend analysis in the 11 stations, positive trends of random nature were observed, suggesting increasing alterations in the analyzed variables. Therefore, the trend analysis performed by the Mann-Kendall test in the precipitation, and maximum and minimum temperature climate series, indicated that several data series showed increasing trends, suggesting a possible increase in precipitation and temperature values over the years. The results of the Kruskal-Wallis and Wald-Wolfowitz tests for homogeneity presented more than 87% of homogeneous stations.

Effects of Rainfall on Yield of Grain Sorghum in the Sudan

1975 ◽  
Vol 11 (3) ◽  
pp. 167-171 ◽  
Author(s):  
Faisal M. Ali
Keyword(s):  
Positive Association ◽  
Grain Sorghum ◽  
Negative Association ◽  
Monthly Rainfall ◽  
Total Rainfall ◽  
Related Variation ◽  
Annual Total

SUMMARYThe effects of rainfall on yield of rainfed grain sorghum in a rotation experiment have been investigated over six years. There was a positive association between yield and rainfall during May and from the beginning of July to the first half of September, but a negative association at other times of the year. Total rainfall in August and September, and the annual total, were positively related to yield, while the totals of June and July were inversely related. Variation in monthly rainfall accounted for up to 86 per cent of the variation in yield, while the total rainfall in August and September accounted for up to 96 per cent.

scholarly journals Due liabilities of territorial self-government units – the scope of disclosures

2020 ◽  
Vol 108 (164) ◽  
pp. 9-22
Author(s):  
Dorota Adamek-Hyska ◽  
Iwona Franczak
Keyword(s):  
Public Finance ◽  
Public Debt ◽  
Research Methodology ◽  
Statistical Tests ◽  
Statistical Significance ◽  
Financial Statement ◽  
Legal Regulations ◽  
The Public ◽  
The Relationship ◽  
Non Parametric

The article is an analysis of disclosures of due liabilities in the system of reporting used by territorial self- government units. The due liabilities (i.e., liabilities that have not been settled on time or liabilities that are past) of the units in question infringe legally regulated principles of managing public means, i.e., they are a factor that results in the loss of financial liquidity, and they infringe discipline of the public finance. Due liabilities are also a debt that is included in public debt. The article includes analyses of budget financial state- ments that refer to the expenditure plans and financial operations of territorial self-government units in the Silesian Province in the period 2016-2018. The research methodology was adjusted to the variables and is based on non-parametric statistical tests. The ANOVA Kruskal-Wallis test by ranks was used to test the statistical significance of differences between the distribution of a variable that describes the relationship between due liabilities to total liabilities and a selected nominal variable. Legal regulations and relevant public finance literature and budget financial statement reporting literature were also subject to this research.

scholarly journals Analysis of Decadal Rainfall and Temperature Trend in Warri, Nigeria

2021 ◽  
Vol 2 (2) ◽  
pp. 15-18
Author(s):  
Oyeleke Oluwaseun Oyerinde
Keyword(s):  
Temperature Trend ◽  
Monthly Rainfall ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Total Rainfall ◽  
Monthly Temperature ◽  
Increasing Trend ◽  
Temperature Ranges ◽  
The Mean ◽  
Using Data

This study investigates rainfall and temperature trend in Warri, Delta State, Nigeria using data derived from Nigerian Meteorological Agency between 2005 and 2015. Data was analyzed to reveal trend in temperature and rainfall values in the years under study and to determine whether there were significant variations. Analysis of rainfall data shows that 2007 had the lowest total rainfall over the 11 year period with a total annual rainfall of 2030.58 mm while 2015 was the year with the highest annual rainfall record of 3183.6 mm. The mean monthly Rainfall indicates that January has the lowest record of rainfall with a total of 36.9 mm while July is the month with highest value of 423.2 mm. Results further indicates that June has the lowest mean monthly temperature over the 11 year period of 20 ºC while March has the highest record of 29.6 ºC. Dominant temperature ranges between 26.1 oC and 26.8 ºC closely followed by 27.7–28.4 ºC which are quite close to the mean monthly values in the area. Analysis of rainfall data confirms an increasing trend.

scholarly journals Trend Analysis of Annual and Monthly Rainfall in Erbil City, Kurdistan Region, Iraq

2019 ◽  
Vol 9 (2) ◽  
pp. 30-36 ◽  
Author(s):  
Saud A. Hussien ◽  
Basil Y. Mustafa ◽  
Farzand K. Medhat
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Trend Analysis ◽  
Linear Regression Analysis ◽  
Monthly Rainfall ◽  
Annual Rainfall ◽  
Sen’S Slope Estimator ◽  
Sen’S Slope ◽  
Slope Estimator ◽  
Non Parametric

The objective of this study is to identify the trend for the annual and monthly rainfall time series data from 1963–1964 to 2018–2019 for Erbil city rainfall gauging station. The trend analysis was conducted for only rainy months (from October to May) using the non-parametric Mann-Kendall test, whereas a non-parametric Sen’s slope estimator was used to determine the magnitude of the trend. A functional relationship has been developed between variables using linear regression analysis to determine a linear trend of rainfall for the study area. The annual trend analysis revealed negative (decreasing) trend because the Kendall’s tau (Z) value and the Sen’s slope estimator magnitude were both negative and found to be −0.093 and −1.37, respectively, and the slope of the linear regression analysis was also negative and equal to −0.9148 mm/year, which represents the rate of yearly annual rainfall decreasing trend. Considering the result of monthly rainfall, the trend analysis of rainfall has suggested that there is a trend variation of rainfall in the rainy months. Further, the analysis revealed a negative (decreasing) trend for months November, January, February, March, April, and May and positive (increasing) trend for months October and December. This study is important as it greatly contributes in water resources system planning and management in this region. Furthermore, the results obtained in this work are promising and might help hydraulic civil and water resource engineers in the design of hydraulic structures.

scholarly journals Rainfall Trend Analysis in Tehsils of Palghar District, Maharashtra State, India

2021 ◽  
Vol 9 (11) ◽  
pp. 238-253
Author(s):  
Dr. Sumit M. Dhak
Keyword(s):  
Trend Analysis ◽  
Linear Trend ◽  
Daily Rainfall ◽  
Kendall Test ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Rainfall Trend ◽  
Department Of Agriculture ◽  
Increasing Trend ◽  
Slope Estimator

Abstract: A detailed trend analysis of monthly and annual rainfall for Tehsils of Palghar district were carried out using 22 years (1998-2019) daily rainfall data taken from Department of Agriculture, Maharashtra State. In this study, to analyse the trend, the non-parametric test (Mann-Kendall test) and Sen’s slope estimator were used. For developing a functional relationship between variables, a linear trend of rainfall data for the studied area evaluated using the linear regression. The results showed that the trend analysis of monthly rainfall has a varied trend of rainfall in the rainy months in tehsil of Palghar District. The month of July significant increasing trend was observed at Jawhar (42.91 mm/year), Vikramgad (29.90 mm/year), Wada (24.06 mm/year), Talasari (31.36 mm/year), Palghar (25.299 mm/year), Mokhada (29.96 mm/year) and Dahanu (38.14 mm/year), whereas non-significant increasing trend 2.76 mm/year was observed at Vasai tehsil of Palghar District during 1998-2019. The month of June, August, September and October rainfall did not show any significant trend in tehsil of Palghar District and non significant decreasing as well as non significant increasing trend was observed in tehsil of Palghar District during 1998 – 2019. The result concluded that annual rainfall trend was increased in Jawhar, Vikramgad, Wada, Talasari, Palghar, Mokhada and Dahanu; whereas Vasai tehsil rainfall trend was decreased in tehsil of Palghar District during 1998 -2019. Keywords: Rainfall, Trend Analysis, Mann Kendall’s Test, Sen Slopes, Regression

Sign in / Sign up

Export Citation Format

Share Document