scholarly journals Rainfall trend analysis using Mann-Kendall and Sen’s slope estimator test in West Kalimantan

2021 ◽  
Vol 893 (1) ◽  
pp. 012006
Author(s):  
F Aditya ◽  
E Gusmayanti ◽  
J Sudrajat
Keyword(s):  
Climate Change ◽  
Rainfall Variability ◽  
Annual Rainfall ◽  
Sen’S Slope Estimator ◽  
West Kalimantan ◽  
Rainfall Analysis ◽  
Sen’S Slope ◽  
Rainfall Trends ◽  
Slope Estimator ◽  
The Impact

Abstract Climate change has been a prominent issue in the last decade. Climate change on a global scale does not necessarily have the same effect in different regions. Rainfall is a crucial weather element related to climate change. Rainfall trends analysis is an appropriate step in assessing the impact of climate change on water availability and food security. This study examines rainfall variations and changes at West Kalimantan, focusing on Mempawah and Kubu Raya from 2000-2019. The Mann-Kendall (MK) and Sen's Slope estimator test, which can determine rainfall variability and long-term monotonic trends, were utilized to analyze 12 rainfall stations. The findings revealed that the annual rainfall pattern prevailed in all locations. Mempawah region tends to experience a downward trend, while Kubu Raya had an upward trend. However, a significant trend (at 95% confidence level) was identified in Sungai Kunyit with a slope value of -33.20 mm/year. This trend indicates that Sungai Kunyit will become drier in the future. The results of monthly rainfall analysis showed that significant upward and downward trends were detected in eight locations. Rainfall trends indicate that climate change has occurred in this region.

Spatio-temporal Trend Detection of Rainfall for Climate Change Assessment in Ahmedabad-Gandhinagar District of Gujarat State, India

2021 ◽  
Vol 7 (1) ◽  
pp. 69-78
Author(s):  
Geeta S. Joshi ◽  
Payal Makhasana
Keyword(s):  
Climate Change ◽  
Rain Gauge ◽  
The State ◽  
Monthly Rainfall ◽  
Trend Detection ◽  
Annual Rainfall ◽  
Sen’S Slope Estimator ◽  
Sen’S Slope ◽  
Mk Test ◽  
Slope Estimator

The present research aims to assess the historical change in rainfall patterns with the changing climate in the Ahmedabad-Gandhinagar district in the state of Gujarat in India. The Mann-Kendall (MK) test along with Sen’s slope estimator have been used for detecting the trend of rainfall data series. The trend of annual rainfall is carried out for – (1) six rain gauge stations established by the State Water Data Center (SWDC) and (2) 11 grid data available from the National Center for Environmental Prediction-Climate Forecast System Reanalysis (NCEP-CFSR) for 35 years starting from 1979 to 2013. Results obtained from these two data sets for the trend detection were found consistent. Furthermore, the analyses of annual and monthly rainfall using MK test and Sen’s slope estimator at six rain gauge stations are carried out in three time periods i.e. 1974-1987, 1988-2001 and 2002-2016. The inverse distance weighted (IDW) method of interpolation is used for the results obtained from the spatial distribution of the temporal rainfall trend for interpolating the station value over the study area. Annual rainfall for data length of 1979 to 2013 shows an increasing trend. The trend of annual and monthly rainfall for July and September shows a positive trend for the span 2002-2016. This study would be useful to the water resource department and policymakers for climate change adaptation in the study area.

scholarly journals Trend analysis of rainfall using Mann-Kendall, Sen’s slope, moving average and least square techniques for Ahmednagar district of Maharashtra

2021 ◽  
Vol 17 (1) ◽  
pp. 19-25
Author(s):  
Virendra N. Barai ◽  
Rohini M. Kalunge
Keyword(s):  
Time Series ◽  
Trend Analysis ◽  
Moving Average ◽  
Rainfall Variability ◽  
Least Square ◽  
Annual Rainfall ◽  
Series Data ◽  
Sen’S Slope ◽  
Increasing Trend ◽  
The Impact

The long-term behaviour of rainfall is necessary to study over space with different time series viz., annual, monthly and weekly as it is one of the most significant climatic variables. Rainfall trend is an important tool which assesses the impact of climate change and provides direction to cope up with its adverse effects on the agriculture. Several studies have been performed to establish the pattern of rainfall over various time periods for different areas that can be used for better agricultural planning, water supply management, etc. Consequently, the present report, entitled “Trend analysis of rainfall in Ahmednagar district of Maharashtra,” was carried out. 13 tahsils of the district of Ahmednagar were selected to carry out trend analysis. The daily rainfall data of 33 years (1980- 2012) of all stations has been processed out study the rainfall variability. The Mann Kendall (MK) Test, Sen’s slope method, moving average method and least square method were used for analysis. The statistical analysis of whole reference time series data highlighted that July and August month contributes highest amount of rainfall at all tahsils. Regarding trend in annual rainfall, these four methods showed increasing trend at most of the tahsils whereas a decreasing trend only at Shrigonda tahsil. For monthly trend analysis, Kopargaon, Newasa, Shevgaon and Shrirampur tahsils showed an increasing trend during July. During August and September month, most of the tahsils i.e. Kopargaon, Nagar, Parner and Sangamner showed increasing trends, whereas in June, only Shrigonda tahsil showed decreasing trend.

scholarly journals Spatiotemporal Trend Analysis of the Mean Annual Rainfall in Senegal

2016 ◽  
Vol 12 (12) ◽  
pp. 231 ◽  
Author(s):  
Lamine Diop ◽  
Ansoumana Bodian ◽  
Dior Diallo
Keyword(s):  
Kendall Test ◽  
Annual Rainfall ◽  
Positive Trend ◽  
Sen’S Slope Estimator ◽  
Small Areas ◽  
Sen’S Slope ◽  
Trend Magnitude ◽  
North East ◽  
Spatiotemporal Trends ◽  
Slope Estimator

The spatiotemporal trends of annual rainfall in Senegal during 1940 - 2013 were investigated using the Mann–Kendall test and Theil–Sen’s slope estimator. Theil and Sen's slope estimator test was used for finding the magnitude of change over a time period. Inverse Weight Distance (IDW) technique in Arc GIS 10.2 was used to investigate spatial patterns of the trends over the entire country. For the period 1940-2013, the results of the analysis showed negative trends in annual rainfall at the whole country except for the Bakel station which exhibits a positive trend but not significant. While for the period 1984 - 2013, all the stations show a positive trend with 07 out of 22 stations exhibiting a significant trend at the 95% confidence interval. The spatial distribution of trend during the period 1940- 2013 showed a significant negative trend in the whole study of area except small areas located at the extreme South Est and West as well as North East and West. The trend magnitude varies between -4.41mm/year to 1.34 mm for the period 1940-2013 with a maximum negative magnitude at the Tambacounda station. For 1984-2013, the trend magnitude is positive for the whole country with values varying between 2.67 mm/year at Goudiry and 12.2 mm/year at Ziguinchor. Magnitudes are greater than 5 mm/year, for stations with significant positive 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 Analysis of precipitation variability over Satluj Basin, Himachal Pradesh, India: 1901–2013

2020 ◽  
Author(s):  
Nity Tirkey ◽  
P. K. Parhi ◽  
A. K. Lohani ◽  
S. K. Chandniha
Keyword(s):  
Climatic Variability ◽  
Himachal Pradesh ◽  
The State ◽  
Spatial And Temporal Variation ◽  
Sen’S Slope Estimator ◽  
Sen’S Slope ◽  
Seasonal Time Series ◽  
Slope Estimator ◽  
Level Of Significance ◽  
The Impact

Abstract Himachal Pradesh is a mountainous state in the Indian Himalayas, which spreads over an area of 55,000 km2. The state has a unique geography, which influences the climatic variability of the state. In the present study, Satluj basin has been considered as a study area. This basin experiences frequent floods, erratic distribution of rainfall and climatic variabilities, which causes extensive damage over the basin. Precipitation is one of the most crucial meteorological variables which determines the impact of climate change in the Himalayan landmass. For spatial and temporal variation of precipitation, long-term precipitation data of 113 years (1901–2013) was utilized. Further, non-parametric, i.e. Mann–Kendall (MK) and modified Mann–Kendall (MMK) tests, were performed to check possible trends and Sen's slope estimator (SSE) test was used for determining the change in magnitude over the basin at 95% level of significance. The entire analysis was performed on a monthly, annual and seasonal (pre-monsoon, monsoon, post-monsoon and winter) basis. In this study, it was noticed that both positive and negative trends are detected in monthly and seasonal time series. It was also noticed that similar results have been estimated in MK, MMK and Sen's slope estimator tests during 1901–2013.

scholarly journals Analysis of Climate Variability and Trends in Southern Ethiopia

Climate ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 96
Author(s):  
Abrham Belay ◽  
Teferi Demissie ◽  
John W. Recha ◽  
Christopher Oludhe ◽  
Philip M. Osano ◽  
...  
Keyword(s):  
Rainfall Variability ◽  
Rate Of Change ◽  
Mitigation Strategies ◽  
Annual Rainfall ◽  
Southern Ethiopia ◽  
Drought Indices ◽  
Trend Test ◽  
Rainfall Trends ◽  
Slope Estimator ◽  
Normal Rainfall

This study investigated the trends and variability of seasonal and annual rainfall and temperature data over southern Ethiopia using time series analysis for the period 1983–2016. Standard Anomaly Index (SAI), Coefficient of Variation (CV), Precipitations Concentration Index (PCI), and Standard Precipitation Index (SPI) were used to examine rainfall variability and develop drought indices over southern Ethiopia. Temporal changes of rainfall trends over the study period were detected using Mann Kendall (MK) trend test and Sen’s slope estimator. The results showed that the region experienced considerable rainfall variability and change that resulted in extended periods of drought and flood events within the study period. Results from SAI and SPI indicated an inter-annual rainfall variability with the proportions of years with below and above normal rainfall being estimated at 56% and 44% respectively. Results from the Mann Kendall trend test indicated an increasing trend of annual rainfall, Kiremt (summer) and Bega (dry) seasons whereas the Belg (spring) season rainfall showed a significant decreasing trend (p < 0.05). The annual rate of change for mean, maximum and minimum temperatures was found to be 0.042 °C, 0.027 °C, and 0.056 °C respectively. The findings from this study can be used by decision-makers in taking appropriate measures and interventions to avert the risks posed by changes in rainfall and temperature variability including extremes in order to enhance community adaptation and mitigation strategies in southern Ethiopia.

Climatic change effects on seasonal patterns of pasture production in New Zealand

1990 ◽  
pp. 43-46 ◽  
Author(s):  
J.A. Baars ◽  
J.E. Radcliffe ◽  
M.D. Rollo
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Rainfall Variability ◽  
Seasonal Pattern ◽  
Regional Climate ◽  
Production Model ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Pasture Production ◽  
The Impact

The performance of livestock industries in New Zealand is affected by a large spatial and seasonal variability in patterns of pasture production. A software package of a database and a predictive pasture production model has been used to make an initial evaluation of the impact of climate change expected around 2030, on the average seasonal pattern of pasture growth at four sites in New Zealand. Mean annual temperature is expected to be 1.2-1.8" C warmer and annual rainfall 510% less. On two cooler/ wetter sites in Southland and Canterbury (irrigated) the predicted pasture production, compared with present, was substantially better in winter (+80%, +50% respectively), better in spring and autumn (+20 to 40%), and unchanged in summer. On two warmer/ drier sites in East Coast (North Island) and Waikato, similar analyses showed improved autumn and winter growth (20-40%) with production unchanged in spring and slightly depressed in summer. Annual production was increased by 20% at South Island sites and about 5% at North Island sites. The onset of spring growth was 2-4 weeks earlier at all sites. Present technology would be expected to be able to formulate management strategies to cope with pasture changes of this magnitude. More reliable predictions of pasture growth will depend on improved climate models which can predict seasonal change in regional climate throughout New Zealand, especially rainfall variability. Keywords climate change, pasture production, mathematical modelling, regional climate

scholarly journals Assessment of Seasonal and Annual Rainfall Trends and Variability in Sharjah City, UAE

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Tarek Merabtene ◽  
Mohsin Siddique ◽  
Abdallah Shanableh
Keyword(s):  
Climate Change ◽  
Temporal Variability ◽  
Low Frequency ◽  
Annual Rainfall ◽  
Spatial And Temporal Variability ◽  
Rainfall Trend ◽  
Significant Drop ◽  
Statistical Measures ◽  
Rainfall Trends ◽  
The Impact

Although a few studies on rainfall spatial and temporal variability in the UAE have been carried out, evidence of the impact of climate change on rainfall trends has not been reported. This study aims at assessing the significance of long-term rainfall trends and temporal variability at Sharjah City, UAE. Annual rainfall and seasonal rainfall extending over a period of 81 years (1934–2014) recorded at Sharjah International Airport have been analyzed. To this end, several parametric and nonparametric statistical measures have been applied following systematic data quality assessment. The analyses revealed that the annual rainfall trend decreased from −3 mm to −9.4 mm per decade over the study periods. The decreasing annual rainfall trend is mainly driven by the significant drop in winter rainfall, particularly during the period from 1977 to 2014. The results also indicate that high probability extreme events have shifted toward low frequency (12.7 years) with significant variations in monthly rainfall patterns and periodicity. The findings of the present study suggest reevaluating the derivation of design rainfall for infrastructure of Sharjah City and urge developing an integrated framework for its water resources planning and risk under climate change impacts scenarios.

scholarly journals Impact of Climate Change on Rainfall Distribution on Cassava Yield in Coastal and Upland Areas of Akwa Ibom State, Nigeria

2020 ◽  
pp. 44-53
Author(s):  
Isaiah A. I. ◽  
Yamusa A. M. ◽  
Odunze A. C.
Keyword(s):  
Climate Change ◽  
Rainfall Variability ◽  
Daily Rainfall ◽  
High Yield ◽  
Annual Rainfall ◽  
Yield Data ◽  
Continuous Increase ◽  
Rainfall Trends ◽  
Yield Time ◽  
The Relationship

This study examined the implication of rainfall variability on cassava yield in selected coastal and upland areas of Akwa Ibom State, Nigeria. Thirty years daily rainfall data were collected from Nigeria Meteorological Agency (1989 – 2018); cassava yield data were also collected from Akwa Ibom State Ministry of Agriculture Uyo (1989 – 2018). Descriptive statistics was used to determine the average annual rainfall and cassava yield. Time series analysis were used to assess the relationship between rainfall and cassava yield. The result indicated an increase in rainfall trends in all areas with Eket – r2 = 0.6631, Oron - r2 = 0.5329, Uyo - r2 = 0.4215 and Ikot Ekpene - r2 = 0.4042. The result also showed an increase in yield of cassava in Uyo and Ikot Ekpene at r2 = 0.2436 and 0.4397 respectively; while its decreases in Eket and Oron at r2 = 0.0611 and 0.1159 respectively. This suggested that a high yield of cassava may be achieved only in the upland areas of Akwa Ibom State due to continuous increase in rainfall as a result of climate change.

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