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.

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.

scholarly journals Analysis of rainfall trends over Tripura

MAUSAM ◽  
2022 ◽  
Vol 73 (1) ◽  
pp. 27-36
Author(s):  
RANJAN PHUKAN ◽  
D. SAHA
Keyword(s):  
Heavy Rainfall ◽  
Monsoon Season ◽  
Rainfall Variability ◽  
Kendall Test ◽  
Annual Rainfall ◽  
The North ◽  
Rainfall Trends ◽  
Annual Scale ◽  
Increasing Trends ◽  
Rainy Days

Rainfall in India has very high temporal and spatial variability. The rainfall variability affects the livelihood and food habits of people from different regions. In this study, the rainfall trends in two stations in the north-eastern state of Tripura, namely Agartala and Kailashahar have been studied for the period 1955-2017. The state experiences an annual mean of more than 2000 mm of rainfall, out of which, about 60% occurs during the monsoon season and about 30% in pre-monsoon. An attempt has been made to analyze the trends in seasonal and annual rainfall, rainy days and heavy rainfall in the two stations, during the same period.Non-parametric Mann-Kendall test has been used to find out the significance of these trends. Both increasing and decreasing trends are observed over the two stations. Increasing trends in rainfall, rainy days and heavy rainfall are found at Agartala during pre-monsoon season and decreasing trends in all other seasons and at annual scale. At Kailashahar, rainfall amount (rainy days & heavy rainfall) is found to be increasing during pre-monsoon and monsoon seasons (pre-monsoon season). At annual scale also, rainfall and rainy days show increasing trends at Kailashahar. The parameters are showing decreasing trends during all other seasons at the station. Rainy days over Agartala show a significantly decreasing trend in monsoon, whereas no other trend is found to be significant over both the stations.  

scholarly journals Long term rainfall variability and trend analysis in lower Shivaliks of Punjab, India

MAUSAM ◽  
2021 ◽  
Vol 72 (3) ◽  
pp. 571-582
Author(s):  
NAVNEET KAUR ◽  
ABRAR YOUSUF ◽  
M. J. SINGH
Keyword(s):  
Trend Analysis ◽  
Monsoon Rainfall ◽  
Rainfall Variability ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Entire Study ◽  
Seasonal Basis ◽  
Normal Rainfall ◽  
Rainy Days

The trend analysis of historical rainfall data on monthly, annual and seasonal basis for three locations in lower Shivaliks of Punjab, viz., Patiala-ki-Rao (1982-2015), Ballowal Saunkhri (1987-2015) and Saleran (1984-2017) has been done in the present study using linear regression model, Mann Kendall test and Sen’s slope. Further, the data for annual and seasonal rainfall and rainy days has also been analyzed on quindecennial basis, i.e., for the period of 1986-2000 and 2001-2015. The analysis of data showed that annual rainfall in the region ranged from 1000 to 1150 mm. The trend analysis of the data shows that the monthly rainfall is decreasing at Patiala-ki-Rao and Saleran, however, the trend was significant for May at Patiala-ki-Rao; and in March and November at Saleran. At Ballowal Saunkhri, the decreasing trend is observed from May to October, however, the trend is significant only in August. The decrease in annual and monsoon rainfall is about 13 to 17 mm and 12 to 13 mm per year respectively at three locations in lower Shivaliks of Punjab. The highest annual (1600-2000 mm) and monsoon (1500-1800 mm) rainfall during the entire study period was recorded in the year 1988 at three locations. The decadal analysis of the data shows below normal rainfall during April to October. The analysis of the rainfall and rainy days on monthly, annual and seasonal averages of 15 year basis showed that both rainfall and rainy days have decreased during the 2001-2015 as compared to 1986-2000 during all the seasons of the year.

scholarly journals Trend Analysis of Rainfall Data in Magelang District Using Mann-Kendall Test and Modification Mann-Kendall Variation

AGRIFOR ◽  
2018 ◽  
Vol 17 (2) ◽  
pp. 293 ◽  
Author(s):  
Joko Suryanto ◽  
Joko Krisbiyantoro
Keyword(s):  
Kendall Test ◽  
Significant Trend ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Partial Sums ◽  
Trend Test ◽  
Positive Trend ◽  
Mk Test ◽  
Rainfall Trends ◽  
Negative Significant Trend

The objective of the research was to analyzed rainfall trends from 6 rainfall stations Kajoran, Mendut, Muntilan, Ngablak, Salaman and Tempuran rainfall station in different time scales (monthly, 3-months periodicityand annual). Identification homogenity of the rainfall data period 1986-2016 for Magelang district using Rescaled Adjusted Partial Sums (RAPS) methode. The three non-parametric tests, Mann-Kendall (MK), modified Mann-Kendall (MMK), trend free prewhitening Mann-Kendall (TFPW-MK) and Sen’s slope wereemployed to assess significance of trends and detecting magnitude of trends.The results shows that monthly rainfall have no significant trend using MK, MMK, and TFPW-MK test at 0.05 level significance. Rainfall 3-month based January-February-March (JFM) period Kajoran station have negative significant trend with magnitude 19.4 mm/3-month. Mendut station have positive trend for April-May-June (AMJ) period with magnitude 6.75 mm/3-month. No significant trends at 0.05 level significance using MK trend test were detected in annual rainfall for 6 rainfall stations.

Climatic Influences on Midwest Drought during the Twentieth Century

2008 ◽  
Vol 21 (3) ◽  
pp. 517-531 ◽  
Author(s):  
Warren B. White ◽  
Alexander Gershunov ◽  
Jeffrey Annis
Keyword(s):  
Twentieth Century ◽  
Rainfall Variability ◽  
Annual Rainfall ◽  
Canonical Correlations ◽  
Sst Variability ◽  
Eastern Equatorial Pacific ◽  
The Pacific ◽  
The 1950S ◽  
Interdecadal Oscillation ◽  
Normal Rainfall

Abstract The Dustbowl Era drought in the 1930s was the principal Midwest drought of the twentieth century, occurring primarily in late spring–summer [April–August (AMJJA)] when &gt;70% of annual rainfall normally occurred. Another major Midwest drought occurred in the 1950s but primarily in fall–early winter [September–December (SOND)] when normal rainfall was ∼1/2 as much. Optimized canonical correlation analysis (CCA) is applied to forecast AMJJA and SOND Midwest rainfall variability in cross-validated fashion from antecedent DJF and JJA sea surface temperature (SST) variability in the surrounding oceans. These CCA models simulate (i.e., hindcast, not forecast) the Dustbowl Era drought of the 1930s and four of seven secondary AMJJA droughts (≥3-yr duration) during the twentieth century, and the principal Midwest drought of the 1950s and one of three secondary SOND droughts. Diagnosing the model canonical correlations finds the superposition of tropical Pacific cool phases of the quasi-decadal oscillation (QDO) and interdecadal oscillation (IDO) responsible for secondary droughts in AMJJA when ENSO was weak and finds the eastern equatorial Pacific cool phase of the ENSO responsible for secondary droughts during SOND when ENSO was strong. These explain why secondary droughts in AMJJA occurred more often (nearly every decade) and were of longer duration than secondary droughts in SOND when decadal drought tendencies were usually interrupted by ENSO. These diagnostics also find the AMJJA Dustbowl Era drought in the 1930s and the principal SOND drought in the 1950s driven primarily by different phases (i.e., in quadrature) of the pentadecadal signal in the Pacific decadal oscillation (PDO).

scholarly journals Long-Term Rainfall Trends and Their Variability in Mainland Portugal in the Last 106 Years

Climate ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 146
Author(s):  
Maria Manuela Portela ◽  
Luis Angel Espinosa ◽  
Martina Zelenakova
Keyword(s):  
Temporal Variability ◽  
Annual Rainfall ◽  
Small Country ◽  
Rain Gauges ◽  
Mainland Portugal ◽  
Mk Test ◽  
Rainfall Trends ◽  
Slope Estimator ◽  
European Coast

This study addresses the long-term rainfall trends, their temporal variability and uncertainty over mainland Portugal, a small country on the most western European coast. The study was based on monthly, seasonal and annual rainfall series spanning for a period of 106 years, between October 1913 and September 2019 (herein after referred to as global period), at 532 rain gauges evenly distributed over the country (c.a. 6 rain gauges per 1000 km2). To understand the rainfall behavior over time, an initial sub-period with 55 years and a final sub-period with 51 years were also analyzed along with the global period. The trends identification and the assessment of their magnitude were derived using the nonparametric Mann-Kendall (MK) test coupled with the Sen’s slope estimator method. The results showed that after the initial sub-period with prevailing increasing rainfall, the trends were almost exclusively decreasing. They were also so pronounced that they counterbalanced the initial rainfall increase and resulted in equally decreasing trends for the global period. The study also shows that approximately from the late 1960s on, the rainy season pattern has changed, with the last months prior to the dry season showing a sustained decrease of their relative contributions to the annual rainfalls. Overall, the results support the hypothesis of less uncertainty on the pronounced decrease of rainfall over mainland Portugal in recent years, which is expected to continue. They also show that the asymmetry between a less wet North, yet still wet, and an arid South is becoming much more marked.

scholarly journals Trend Analyses of Temperature and Rainfall and Their Response to Global CO2 Emission in Masha, Southern Ethiopia

2019 ◽  
Vol 34 (1) ◽  
pp. 67
Author(s):  
Fedhasa Benti ◽  
Magarsa Abara
Keyword(s):  
Crop Production ◽  
Meteorological Station ◽  
Summer Season ◽  
Crop Damage ◽  
Annual Rainfall ◽  
Southern Ethiopia ◽  
Seasonal Temperature ◽  
Seed Supply ◽  
Rainfall Trends ◽  
The Relationship

Ethiopia is one of the most vulnerable countries to climate change and often signifies higher probabilities of droughts that have historically affected millions of farmers. The variability in rainfall patterns and drought have disrupted crop production and exacerbated food insecurity in many parts of Ethiopia. This study aimed to investigate seasonal and annual temperature and rainfall trends and their association to the global CO<sub>2</sub> emission. Temperature and rainfall data obtained from the Masha meteorological station and CO<sub>2</sub> from EDGAR 4.3.2 dataset recorded for 36 years. The Linear regression model was used to analyse seasonal temperature and rainfall trends. Pearson’s correlation coefficient employed to measure the relationship between temperature and rainfall and global CO<sub>2</sub> emission. The results showed that there were significant warming trends of seasonal and annual mean temperatures while summer season and annual rainfall significantly declined. The prediction results showed that the summer and annual mean temperatures would be significantly increased while the rainfall decreased for the next 35 years. The cumulative global CO<sub>2</sub> and annual mean temperature and rainfall were correlated significantly at P = 0.0004 and 0.006 for temperature and rainfall, respectively. The results demonstrated clearly that the increasing of temperature and the decreasing of rainfall had a direct relationship with the global CO<sub>2</sub> emissions and suggested that there should be a sound soil and water management, short season seed supply and pipe irrigation practices to reduce the future crop damage in the area.

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.

scholarly journals Socializing the rain: human adaptation to ecological variability in a fishery, Mweru-Luapula, Zambia

2019 ◽  
Vol 26 (1) ◽  
pp. 224 ◽  
Author(s):  
Christopher M. Annear ◽  
Peter R. Waylen
Keyword(s):  
Political Ecology ◽  
Rainfall Variability ◽  
Annual Rainfall ◽  
Fish Production ◽  
Learning To Read ◽  
Socioeconomic Environment ◽  
Ecological Variability ◽  
South Central ◽  
Rainfall Trends ◽  
Fish Catch

<p><strong>Abstract </strong></p><p>Rainfall drives fishery fertility in Mweru-Luapula, thus rainfall variability contributes to frequent changes in fishing catches. Fishers and traders have adapted their institutions to this variable ecology in a variety of ways, including learning to read the fishery for productive periods and practicing multiple modes of income procurement. By accurately identifying inter-annual, inter-decadal, and longer spans of rainfall trends, future high and low yields can be forecast. This article presents and analyzes annual rainfall in the fishery from 1916-1992 and quantitative fish market data comprised of observed fish catch numbers by species in three markets from September 2004 to September 2005. It uses political ecology to better understand fish production, trade, and subsistence in this South-Central African freshwater fishery. We combine qualitative analysis of fisher and marketer perceptions of the fishery and knowledge of rainfall patterns to show how human behavior is not "tragically" driven, but instead based on the state of the ecological, sociocultural, and socioeconomic environment at a given time.</p><p><strong>Keywords</strong>: African freshwater fisheries, rainfall modeling, political ecology, Mweru-Luapula, Zambia, climate change</p>

scholarly journals Rainfall Variability and Trends over the African Continent Using TAMSAT Data (1983–2020): Towards Climate Change Resilience and Adaptation

2021 ◽  
Vol 14 (1) ◽  
pp. 96
Author(s):  
Niranga Alahacoon ◽  
Mahesh Edirisinghe ◽  
Matamyo Simwanda ◽  
ENC Perera ◽  
Vincent R. Nyirenda ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Water Resource Management ◽  
Rainfall Variability ◽  
Decision Makers ◽  
Annual Rainfall ◽  
African Continent ◽  
Climate Zones ◽  
Mk Test ◽  
Rainfall Trends

This study reveals rainfall variability and trends in the African continent using TAMSAT data from 1983 to 2020. In the study, a Mann–Kendall (MK) test and Sen’s slope estimator were used to analyze rainfall trends and their magnitude, respectively, under monthly, seasonal, and annual timeframes as an indication of climate change using different natural and geographical contexts (i.e., sub-regions, climate zones, major river basins, and countries). The study finds that the highest annual rainfall trends were recorded in Rwanda (11.97 mm/year), the Gulf of Guinea (river basin 8.71 mm/year), the tropical rainforest climate zone (8.21 mm/year), and the Central African region (6.84 mm/year), while Mozambique (−0.437 mm/year), the subtropical northern desert (0.80 mm/year), the west coast river basin of South Africa (−0.360 mm/year), and the Northern Africa region (1.07 mm/year) show the lowest annual rainfall trends. There is a statistically significant increase in the rainfall in the countries of Africa’s northern and central regions, while there is no statistically significant change in the countries of the southern and eastern regions. In terms of climate zones, in the tropical northern desert climates, tropical northern peninsulas, and tropical grasslands, there is a significant increase in rainfall over the entire timeframe of the month, season, and year. This implies that increased rainfall will have a positive effect on the food security of the countries in those climatic zones. Since a large percentage of Africa’s agriculture is based only on rainfall (i.e., rain-fed agriculture), increasing trends in rainfall can assist climate resilience and adaptation, while declining rainfall trends can badly affect it. This information can be crucial for decision-makers concerned with effective crop planning and water resource management. The rainfall variability and trend analysis of this study provide important information to decision-makers that need to effectively mitigate drought and flood risk.

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