scholarly journals Analysis of Past and Projected Trends of Rainfall and Temperature Parameters in Eastern and Western Hararghe Zones, Ethiopia

Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 67
Author(s):  
Helen Teshome ◽  
Kindie Tesfaye ◽  
Nigussie Dechassa ◽  
Tamado Tana ◽  
Matthew Huber

Smallholder farmers in East and West Hararghe zones, Ethiopia frequently face problems of climate extremes. Knowledge of past and projected climate change and variability at local and regional scales can help develop adaptation measures. A study was therefore conducted to investigate the spatio-temporal dynamics of rainfall and temperature in the past (1988–2017) and projected periods of 2030 and 2050 under two Representative Concentration Pathways (RCP4.5 and RCP8.5) at selected stations in East and West Hararghe zones, Ethiopia. To detect the trends and magnitude of change Mann–Kendall test and Sen’s slope estimator were employed, respectively. The result of the study indicated that for the last three decades annual and seasonal and monthly rainfall showed high variability but the changes are not statistically significant. On the other hand, the minimum temperature of the ‘Belg’ season showed a significant (p < 0.05) increment. The mean annual minimum temperature is projected to increase by 0.34 °C and 2.52 °C for 2030, and 0.41 °C and 4.15 °C for 2050 under RCP4.5 and RCP8.5, respectively. Additionally, the mean maximum temperature is projected to change by −0.02 °C and 1.14 °C for 2030, and 0.54 °C and 1.87 °C for 2050 under RCP4.5 and RCP 8.5, respectively. Annual rainfall amount is also projected to increase by 2.5% and 29% for 2030, and 12% and 32% for 2050 under RCP4.5 and RCP 8.5, respectively. Hence, it is concluded that there was an increasing trend in the Belg season minimum temperature. A significant increasing trend in rainfall and temperature are projected compared to the baseline period for most of the districts studied. This implies a need to design climate-smart crop and livestock production strategies, as well as an early warning system to counter the drastic effects of climate change and variability on agricultural production and farmers’ livelihood in the region.

Author(s):  
Raj Bahadur ◽  
R. K. Jaiswal ◽  
A. K. Nema ◽  
Anshu Gangwar ◽  
Sandeep Kumar

Trend analysis is performed to find the pattern that prevails in Nagwan watershed area located in Hazaribagh district of Jharkhand (India) having very high average annual rainfall in the range of 1146 mm. The study aims to investigated the impacts of global warming by examine precipitation and temperature change over a period. Non-parametric MK test and Sen’s Slope estimator were used to assess the trend in long-term rainfall and temperature time series (1981-2019). The analysis has been carried out on monthly, seasonal and annual scale to identify meso-scale climate change effect on hydrological regime. The precipitation in the summer showed an increasing trend (Z value +1.67) and there was increasing trend in the seasonal rainfall which influences the total water availability in the watershed. There was increase in minimum temperature during summer season which shows the impact of global warming and may results in increasing the duration of the summer season. The annual average minimum temperature in the watershed showed an increasing trend (Z value +2.08) at 0.05 level of significance indicated hot nights in the summer. The annual average maximum temperature in the watershed showed a decreasing trend (Z value -1.26). Fluctuation and change in trend of rainfall and temperature possess potential risk hence it is important to understand and identify the pattern of rainfall and temperature for assessing impact of climate change and it is necessary to adopt appropriate steps for agriculture crop planning and improving farmer’s capability to cope with challenging situations due to environmental and climate changes.


2019 ◽  
Vol 60 ◽  
pp. C109-C126 ◽  
Author(s):  
Joshua Hartigan ◽  
Shev MacNamara ◽  
Lance M Leslie

Motivated by the Millennium Drought and the current drought over much of southern and eastern Australia, this detailed statistical study compares trends in annual wet season precipitation and temperature between a coastal site (Newcastle) and an inland site (Scone). Bootstrap permutation tests reveal Scone precipitation has decreased significantly over the past 40 years (p-value=0.070) whereas Newcastle has recorded little to no change (p-value=0.800). Mean maximum and minimum temperatures for Newcastle have increased over the past 40 years (p-values of 0.002 and 0.015, respectively) while the mean maximum temperature for Scone has increased (p-value = 0.058) and the mean minimum temperature has remained stable. This suggests mean temperatures during the wet season for both locations are increasing. Considering these trends along with those for precipitation, water resources in the Hunter region will be increasingly strained as a result of increased evaporation with either similar or less precipitation falling in the region. Wavelet analysis reveals that both sites have similar power spectra for precipitation and mean maximum temperature with a statistically significant signal in the two to seven year period, typically indicative of the El-Nino Southern Oscillation climate driver. The El-Nino Southern Oscillation also drives the Newcastle mean minimum temperature, whereas the Scone power spectra has no indication of a definitive driver for mean minimum temperature. References R. A., R. L. Kitching, F. Chiew, L. Hughes, P. C. D. Newton, S. S. Schuster, A. Tait, and P. Whetton. Climate change 2014: Impacts, adaptation, and vulnerability. Part B: Regional aspects. Contribution of Working Group II to the Fifth Assessment of the Intergovernmental Panel on Climate Change. Technical report, Intergovernmental Panel on Climate Change, 2014. URL https://www.ipcc.ch/report/ar5/wg2/. Bureau of Meteorology. Climate Glossary-Drought. URL http://www.bom.gov.au/climate/glossary/drought.shtml. K. M. Lau and H. Weng. Climate signal detection using wavelet transform: How to make a time series sing. B. Am. Meteorol. Soc., 76:23912402, 1995. doi:10.1175/1520-0477(1995)0762391:CSDUWT>2.0.CO;2. M. B. Richman and L. M. Leslie. Uniqueness and causes of the California drought. Procedia Comput. Sci., 61:428435, 2015. doi:10.1016/j.procs.2015.09.181. M. B. Richman and L. M. Leslie. The 20152017 Cape Town drought: Attribution and prediction using machine learning. Procedia Comput. Sci., 140:248257, 2018. doi:10.1016/j.procs.2018.10.323.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Biniyam Yisehak ◽  
Henok Shiferaw ◽  
Haftu Abrha ◽  
Amdom Gebremedhin ◽  
Haftom Hagos ◽  
...  

Abstract Background Below-normal availability of water for a considerable period of time induces occurrence of drought. This paper investigates the Spatio-temporal characteristics of meteorological drought under changing climate. The climate change was analyzed using delta based statistical downscaling approach of RCP 4.5 and RCP 8.5 in R software packages. The meteorological drought was assessed using the Reconnaissance Drought Index (RDI). Results The result of climate change projections showed that the average annual minimum temperature will be increased by about 0.8–2.9 °C. The mean annual maximum temperature will be also increased by 0.9–3.75 °C. The rainfall projection generally showed an increasing trend, it exhibited an average annual increase of 3.5–13.4 % over the study area. The projected drought events reached its maximum severity indicated extreme drought in the years 2043, 2044, 2073, and 2074. The RDI value shows drought will occurred after 1–6 and 2–7 years under RCP 4.5 and RCP 8.5 emission scenarios respectively over the study area. Almost more than 72 % of the current and future spatial coverage of drought in the study area will be affected by extreme drought, 22.3 % severely and 5.57 % also moderate drought. Conclusions Therefore, the study helps to provide useful information for policy decision makers to implement different adaptation and mitigation measures of drought in the region.


2021 ◽  
Author(s):  
Asis Mukherjee ◽  
Abul Kalam Samsul Huda ◽  
Salil Saha

Abstract High temperature and elevated CO2 under future climate change will influence the agricultural productivity worldwide. Burgeoning population along with climate change situation is going to threaten the food security of India. According to IPCC 5th assessment report (2014), global mean surface temperature and concentration of carbon dioxide (CO2) at the end of 21st century will increase by 4.8°C and 539 ppm respectively under Representative Concentration Pathway (RCP) 8.5 scenario. Considering the burning issue present study aims to find out the probable change in different climatic parameters under high greenhouse gas emission (RCP 8.5) scenario during 2021-2095 and their impact on wheat yield and water productivity over six locations (Jalpaiguri, Nadia, Murshidabad, Malda, Birbhum and South 24 Parganas) covering five major agro-climatic zones of West Bengal, a state of eastern India. Results showed that maximum temperature (Tmax) and minimum temperature (Tmin) will increase by 5.3oC and 5.9oC during the end of this century. The increase in annual rainfall will be maximum (22%) at Murshidabad. Wheat yield will increase by 3 to 28% across the study sites. The seasonal crop evapotranspiration value will decline by 1 to 21%. Both water- use efficiency (WUE) and transpiration -use efficiency (TUE) will increase at all the study sites.


Author(s):  
Sohail Abbas ◽  
Safdar Ali Shirazi ◽  
Nausheen Mazhar ◽  
Kashif Mahmood ◽  
Ashfak Ahmad Khan

Identifying the temperature change at a regional level is one of the essential parameters to determine the intensity of climate change. The current investigation provides an examination of changing trends of temperature in the Punjab province from 1970 to 2019. Sen's slope estimator method is applied to monthly data of mean temperature (Tmean), maximum temperature (Tmax), and minimum temperature (Tmin) to calculate the rate of temperature change. Statistical methods were used to find out the level of significance in terms of negative or positive trends to examine the variability among various weather observatories. Moreover, predicted values have also been observed for a detailed analysis of temperature variability and trends. Significant and pronounced changes in the mean temperature (T mean) are distinguished all over the Punjab regions with an increasing trend from North to South Punjab. In the case of maximum temperature (Tmax), a faster rate of rising in temperature is observed over the Southern and Western regions of Punjab. In contrast, the minimum temperature (Tmin) shows an increasing trend in Central Punjab. The findings provide detailed insight to policymakers for the planning of mitigating efforts and adaptation strategies in response to climate change.


Author(s):  
S. Sridhara ◽  
Pradeep Gopakkali ◽  
R. Nandini

Aims: To know the rainfall and temperature trend for all the districts of Karnataka state to develop suitable coping mechanisms for changing weather conditions during the cropping season. Study Design: The available daily data of rainfall (1971-2011) and minimum and maximum temperature (1971-2007) for each district was collected from NICRA-ICAR website. A non-parametric model such as the Mann-Kendall (MK) test complemented with Sen’s slope estimator was used to determine the magnitude of the trend. Place and Duration of Study: The rainfall data of 41 years (1971-2011) and temperature data of 37 years (1971-2007) was collected for all 27 districts of Karnataka. Methodology: Basic statistics related to rainfall like mean, standard deviation (SD), the coefficient of variation (CV) and the percentage contribution to annual rainfall were computed for monthly and season-wise. Mann-Kendall test was used to detect trend for rainfall as well as temperature. Results: An increasing trend in rainfall during winter, monsoon and annual basis for all most all the districts of Karnataka and decreasing trend of rainfall during pre and post-monsoon season was noticed. An early cessation of rainfall during September month in all most all the districts of Karnataka was observed. Similarly, monthly mean, maximum and the minimum temperature had shown an increasing trend over the past 37 years for all the districts of Karnataka. Conclusion: The more variation in rainfall during the pre-monsoon season was observed, which is more important for land preparation and other operations. The increasing trend of maximum and minimum temperature throughout the year may often cause a reduction in crop yield. It is necessary to change crops with its short duration varieties in order to avoid late season drought.


2020 ◽  
Author(s):  
Biniyam Yisehak ◽  
Henok Shiferaw ◽  
Haftu Abrha ◽  
Amdom Gebremedhin ◽  
Haftom Hagos ◽  
...  

Abstract Background: Below-normal availability of water for a considerable period of time induces occurrence of drought. This paper investigates the characteristics of meteorological drought under changing climate. The meteorological drought was assessed using the Standardized Precipitation Index (SPI) and the Reconnaissance Drought Index (RDI). The climate change was also analyzed using delta based statistical downscaling approach of RCP 4.5 and RCP 8.5 in R software packages. Results: The result of climate change projections showed that the average annual minimum temperature will be increased by about 0.8-2.9°C. The mean annual maximum temperature will be also increased by 0.9-3.75 °C. The rainfall projection generally showed an increasing trend, it exhibited an average annual increase of 3.5-13.4 % over the study area. The drought projection showed that there would be extreme drought events in study area for the future (2018-2099). The SPI result indicates that drought will be occurred in the study area after 1-5 and 1-6 years under RCP 4.5 and 8.5 emission scenarios respectively and the RDI value also shows drought will occurred after 1-6 and 2-7 years under RCP 4.5 and RCP 8.5 emission scenarios respectively over the study area. Almost more than 72% of the current and future spatial coverage of drought in the study area will be affected by extreme drought, 22.3% severely and 5.57% also moderate drought.Conclusions: Therefore, the study helps to provide useful information for policy decision makers to implement different adaptation and mitigation measures of drought in the region.


2021 ◽  
Author(s):  
Daniel Assefa ◽  
Mesfin Mengistu

Abstract BackgroundThe paper focus on time series trend and variability analysis of observed rainfall and temperature records from 16 stations during 1985-2015. ResultsBoth the summer and annual rainfall have an increasing trend but not statistically significant. Regards to variability, low to very high levels of variability were recorded according to the seasons and annual rainfall, whereas, moderate to extremely high levels of variability were observed. The result of the Mann Kendall test portrays that the mean minimum temperature was raised by 0.05 oC, while the maximum temperature was increased rose by 0.03 oC/30 years. The monthly maximum temperature also shows an increasing trend with the lowest record during August (22.05 oC) and the highest in the March (26.49 oC) except in the month of November and December. Similarly, an increasing trend was observed with a mean monthly minimum temperature with the lowest mean of 8.42Co in December and the highest mean of 11.12 oC recorded in April. Besides, a low level of variability was seen both in the case of minimum and maximum temperature were observed in all months. ConclusionsTherefore, since the observed trends of both temperature and total rainfall show abnormal shifts, there is an urgent need for policymakers to design systematic planning and management activities to rain-fed agriculture.


2021 ◽  
Vol 14 (1) ◽  
pp. 327-339
Author(s):  
Kemuel III Quindala ◽  
Diane Carmeliza Cuaresma ◽  
Jonathan Mamplata

The behavior of temperature is one of the major factors in the study of climate change which has already invited a lot of researchers and policymakers. These studies help in deciding the best adaptation and mitigation strategy. However, there are little studies on the progression of climate change in a local setting, such as in a municipal or provincial level. This study explored to model, using regression, the daily temperature in the province of Laguna. The daily maximum and minimum temperature from 1960 to 2018 were modeled using the classical Ornstein-Uhlenbeck (OU) process with additive seasonality. The model showed that the province saw an increase of $1.16^\circ$C (resp. $0.55^\circ$C) in the mean daily minimum (resp. maximum) temperature from 1960 to 2018. It was also found that minimum temperature showed a steadier increase than maximum temperature, which poses threats to agricultural activities. Consistent with other international predictions, there was a $0.02^\circ$C annual increase in 1960 to a $0.05^\circ$C starting in 2010.  The proposed model can be used by authorities in designing and creating adaptive measures that would be more effective to the province of Laguna.


Climate ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 142
Author(s):  
Koffi Djaman ◽  
Komlan Koudahe ◽  
Ansoumana Bodian ◽  
Lamine Diop ◽  
Papa Malick Ndiaye

The objective of this study is to perform trend analysis in the historic data sets of annual and crop season [May–September] precipitation and daily maximum and minimum temperatures across the southwest United States. Eighteen ground-based weather stations were considered across the southwest United States for a total period from 1902 to 2017. The non-parametric Mann–Kendall test method was used for the significance of the trend analysis and the Sen’s slope estimator was used to derive the long-term average rates of change in the parameters. The results showed a decreasing trend in annual precipitation at 44.4% of the stations with the Sen’s slopes varying from −1.35 to −0.02 mm/year while the other stations showed an increasing trend. Crop season total precipitation showed non-significant variation at most of the stations except two stations in Arizona. Seventy-five percent of the stations showed increasing trend in annual maximum temperature at the rates that varied from 0.6 to 3.1 °C per century. Air cooling varied from 0.2 to 1.0 °C per century with dominant warming phenomenon at the regional scale of the southwest United States. Average annual minimum temperature had increased at 69% of the stations at the rates that varied from 0.1 to 8 °C over the last century, while the annual temperature amplitude showed a decreasing trend at 63% of stations. Crop season maximum temperature had significant increasing trend at 68.8% of the stations at the rates varying from 0.7 to 3.5 °C per century, while the season minimum temperature had increased at 75% of the stations.


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