Spatiotemporal Trend Analysis of Temperature and Rainfall over Ziway Lake Basin, Ethiopia

Rainfall and temperature trends detection is vital for water resources management and decision support systems in agro-hydrology. This study assessed the historical (1983–2005) and future (2026–2100) rainfall, maximum temperature (Tmax), and minimum temperature (Tmin) trends of the Ziway Lake Basin (Ethiopia). The daily observed rainfall and temperature data at eleven stations were obtained from the National Meteorological Agency (NMA) of Ethiopia, while simulated historical and future climate data were obtained from the Coupled Model Intercomparison Project 5 (CMIP5) datasets under Representative Concentration Pathways (RCP) of 4.5 and 8.5. The CMIP5 datasets were statistically downscaled by using the climate model data for hydrologic modeling (CMhyd) tool and bias corrected using the distribution mapping method available in the CMhyd tool. The performance of simulated rainfall, Tmax, and Tmin of the CMIP5 models were statistically evaluated using observation datasets at eleven stations. The results showed that the selected CMIP5 models can reasonably simulate the monthly rainfall, Tmax, and Tmin at the majority of the stations. Modified Mann–Kendall trend test were applied to estimate the trends of annual rainfall, Tmax, and Tmin in the historical and future periods. We found that rainfall experienced no clear trends, while Tmax, and Tmin showed consistently significant increasing trends under both RCP 4.5 and 8.5 scenarios. However, the warming is expected to be greater under RCP 8.5 than RCP 4.5 by the end of the 21st century, resulting in an increasing trend of Tmax and Tmin at all stations. The greatest warming occurred in the central part of the basin, with statistically significant increases largely seen by the end of the 21st century, which is expected to exacerbate the evapotranspiration demand of the area that could negatively affect the freshwater availability within the basin. This study increases our understanding of historic trends and projected future change effects on rainfall- and evapotranspiration-related climate variables, which can be used to inform adaptive water resource management strategies.

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Evaluation of CMIP5 Model Precipitation Using PERSIANN-CDR

Journal of Hydrometeorology ◽

10.1175/jhm-d-16-0201.1 ◽

2017 ◽

Vol 18 (9) ◽

pp. 2313-2330 ◽

Cited By ~ 10

Author(s):

Phu Nguyen ◽

Andrea Thorstensen ◽

Soroosh Sorooshian ◽

Qian Zhu ◽

Hoang Tran ◽

...

Keyword(s):

Extreme Precipitation ◽

Climate Model ◽

Model Performance ◽

Model Averaging ◽

Cmip5 Models ◽

Global Evaluation ◽

Climate Data ◽

Climate Zone ◽

Precipitation Estimates ◽

Annual Total

Abstract The purpose of this study is to use the PERSIANN–Climate Data Record (PERSIANN-CDR) dataset to evaluate the ability of 32 CMIP5 models in capturing the behavior of daily extreme precipitation estimates globally. The daily long-term historical global PERSIANN-CDR allows for a global investigation of eight precipitation indices that is unattainable with other datasets. Quantitative comparisons against CPC daily gauge; GPCP One-Degree Daily (GPCP1DD); and TRMM 3B42, version 7 (3B42V7), datasets show the credibility of PERSIANN-CDR to be used as the reference data for global evaluation of CMIP5 models. This work uniquely defines different study regions by partitioning global land areas into 25 groups based on continent and climate zone type. Results show that model performance in warm temperate and equatorial regions in capturing daily extreme precipitation behavior is largely mixed in terms of index RMSE and correlation, suggesting that these regions may benefit from weighted model averaging schemes or model selection as opposed to simple model averaging. The three driest climate regions (snow, polar, and arid) exhibit high correlations and low RMSE values when compared against PERSIANN-CDR estimates, with the exceptions of the cold regions showing an inability to capture the 95th and 99th percentile annual total precipitation characteristics. A comprehensive assessment of each model’s performance in each continent–climate zone defined group is provided as a guide for both model developers to target regions and processes that are not yet fully captured in certain climate types, and for climate model output users to be able to select the models and/or the study areas that may best fit their applications of interest.

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Climate Extremes over the Arabian Peninsula Using RegCM4 for Present Conditions Forced by Several CMIP5 Models

Atmosphere ◽

10.3390/atmos10110675 ◽

2019 ◽

Vol 10 (11) ◽

pp. 675 ◽

Cited By ~ 4

Author(s):

Almazroui

Keyword(s):

Land Surface ◽

Arabian Peninsula ◽

Climate Model ◽

Regional Climate ◽

Coupled Model ◽

Climate Extremes ◽

Maximum Temperature ◽

Cmip5 Models ◽

Study Region ◽

Temperature And Precipitation

This paper investigates the temperature and precipitation extremes over the Arabian Peninsula using data from the regional climate model RegCM4 forced by three Coupled Model Intercomparison Project Phase 5 (CMIP5) models and ERA–Interim reanalysis data. Indices of extremes are calculated using daily temperature and precipitation data at 27 meteorological stations located across Saudi Arabia in line with the suggested procedure from the Expert Team on Climate Change Detection and Indices (ETCCDI) for the present climate (1986–2005) using 1981–2000 as the reference period. The results show that RegCM4 accurately captures the main features of temperature extremes found in surface observations. The results also show that RegCM4 with the CLM land–surface scheme performs better in the simulation of precipitation and minimum temperature, while the BATS scheme is better than CLM in simulating maximum temperature. Among the three CMIP5 models, the two best performing models are found to accurately reproduce the observations in calculating the extreme indices, while the other is not so successful. The reason for the good performance by these two models is that they successfully capture the circulation patterns and the humidity fields, which in turn influence the temperature and precipitation patterns that determine the extremes over the study region.

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Changes in Climate Extremes over North Thailand, 1960–2099

Journal of Climatology ◽

10.1155/2016/4289454 ◽

2016 ◽

Vol 2016 ◽

pp. 1-18 ◽

Cited By ~ 14

Author(s):

Mohammad Badrul Masud ◽

Peeyush Soni ◽

Sangam Shrestha ◽

Nitin K. Tripathi

Keyword(s):

Climate Model ◽

Global Climate ◽

Global Climate Model ◽

Annual Rainfall ◽

Trend Test ◽

Daily Maximum ◽

Climate Extreme ◽

The Future ◽

North Thailand ◽

Extreme Indices

This study analyzes 24 climate extreme indices over North Thailand using observed data for daily maximum and minimum temperatures and total daily rainfall for the 1960–2010 period, and HadCM3 Global Climate Model (GCM) and PRECIS Regional Climate Model simulated data for the 1960–2100 period. A statistical downscaling tool is employed to downscale GCM outputs. Variations in and trends of historical and future climates are identified using the nonparametric Mann-Kendall trend test and Sen’s slope. Temperature extreme indices showed a significant rising trend during the observed period and are expected to increase significantly with an increase in summer days and tropical nights in the future. A notable decline in the number of cool days and nights is also expected in the study area while the number of warm days and nights is expected to increase. There was an insignificant decrease in total annual rainfall, number of days with rainfall more than 10 and 20 mm. However, the annual rainfall is projected to increase by 9.65% in the future 2011–2099 period compared to the observed 1960–2010 period.

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Spatial and temporal patterns of recent and future climate extremes in the Eastern Mediterranean and Middle East region

Natural Hazards and Earth System Sciences Discussions ◽

10.5194/nhessd-1-4425-2013 ◽

2013 ◽

Vol 1 (5) ◽

pp. 4425-4444

Author(s):

E. Kostopoulou ◽

C. Giannakopoulos ◽

M. Hatzaki ◽

A. Karali ◽

P. Hadjinicolaou ◽

...

Keyword(s):

Middle East ◽

21St Century ◽

Climate Model ◽

Eastern Mediterranean ◽

Temporal Trends ◽

Climate Extremes ◽

Maximum Temperature ◽

Area Of Interest ◽

East Region ◽

Middle East Region

Abstract. Recent and future changes in temperature and precipitation climate extremes are estimated using the Hadley Centre PRECIS climate model for the Eastern Mediterranean and Middle East region. The area of interest is considered vulnerable to extreme climate events as there is evidence for a temperature rise while precipitation tends to decline, suggesting likely effects on vital socioeconomic sectors in the region. Observations have been obtained for the recent period (1961–1990) and used to evaluate the model output. The spatial distribution of recent temporal trends in temperature indicates strong increasing in minimum temperature over the eastern Balkan Peninsula, Turkey and the Arabian Peninsula. The rate of warming reaches 0.4–0.5 °C decade−1 in a large part of the domain, while warming is expected to be strongest in summer (0.6–0.7 °C decade−1) in the E-Balkans and W-Turkey. The trends in annual and summer maximum temperature are estimated at approximately 0.5 and 0.6 °C decade−1. Recent estimates do not indicate statistically significant trends in precipitation except for individual sub-regions. Results indicate a future warming trend for the study area over the last 30 yr of the 21st century. Trends are estimated to be positive and statistically significant in nearly the entire region. The annual trend patterns for both minimum and maximum temperature show warming rates of approximately 0.4–0.6 °C decade−1, with pronounced warming over the Middle Eastern countries. Summer temperatures reveal a gradual warming (0.5–0.9 °C decade−1) over much of the region. The model projects drying trends by 5–30% in annual precipitation towards the end of the 21st century, with the number of wet days decreasing at the rate of 10–30 days yr−1, while heavy precipitation is likely to decrease in the high-elevation areas by 15 days yr−1.

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Projected changes in extreme precipitation events over Iran in the 21st century based on CMIP5 models

Climate Research ◽

10.3354/cr01625 ◽

2020 ◽

Vol 82 ◽

pp. 75-95

Author(s):

M Darand

Keyword(s):

21St Century ◽

Extreme Precipitation ◽

Model Simulation ◽

Climate Extremes ◽

Cmip5 Models ◽

Trend Test ◽

Extreme Precipitation Events ◽

Increased Risk ◽

Projected Changes ◽

Precipitation Events

Climate extremes have large impacts on human societies and natural ecosystems. Projection of changes in climate extremes is very important for long-term planning. The current study investigated future changes in extreme precipitation events over Iran based on 18 CMIP5 models for the period 2006-2100. National gridded data from the Asfazari database were used to evaluate climate model simulation. Results indicate that models with higher spatial resolution (CCSM4 and MRI-CGCM3) perform better than those with lower resolution in capturing the spatial features of extreme precipitation events. Bias correction was applied to the models and the projected changes were assessed with the nonparametric modified Mann-Kendal trend test and Sen slope estimator at a 95% confidence level. Annual total precipitation (PRPCTOT) and rainy days (RD) were projected to decrease but the intensity and frequency of precipitation extremes were predicted to increase significantly. The projected decreases were larger in northwestern parts than other regions, with PRPCTOT decreasing by 18 to 22 mm decade-1 and RD by 4 to 4.8 d decade-1. Although there were discrepancies in rates between the models, extreme precipitation events over Iran were generally projected to increase. An increase in consecutive dry days (CDD) was predicted for most regions by the end of the 21st century under RCP8.5, with the largest increase of 5 to 6.8 d decade-1 found for northwestern Iran. In eastern areas of Iran, where precipitation occurs extremely rarely, the number of days with daily precipitation exceeding 10 mm (R10) or even 20 mm (R20) were projected to increase significantly. In conclusion, these changes suggest an increased risk of flash floods in Iran from increased extreme precipitation under the RCP8.5 emission scenario.

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Assessment of Local Climate Change: Historical Trends and RCM Multi-Model Projections Over the Salento Area (Italy)

Water ◽

10.3390/w10080978 ◽

2018 ◽

Vol 10 (8) ◽

pp. 978 ◽

Cited By ~ 3

Author(s):

Marco D’Oria ◽

Maria Tanda ◽

Valeria Todaro

Keyword(s):

Climate Change ◽

Climate Models ◽

Climate Model ◽

Heat Waves ◽

Regional Climate ◽

Warm Season ◽

Annual Rainfall ◽

Maximum Temperature ◽

Monthly Precipitation ◽

Local Climate

This study provides an up-to-date analysis of climate change over the Salento area (southeast Italy) using both historical data and multi-model projections of Regional Climate Models (RCMs). The accumulated anomalies of monthly precipitation and temperature records were analyzed and the trends in the climate variables were identified and quantified for two historical periods. The precipitation trends are in almost all cases not significant while the temperature shows statistically significant increasing tendencies especially in summer. A clear changing point around the 80s and at the end of the 90s was identified by the accumulated anomalies of the minimum and maximum temperature, respectively. The gradual increase of the temperature over the area is confirmed by the climate model projections, at short—(2016–2035), medium—(2046–2065) and long-term (2081–2100), provided by an ensemble of 13 RCMs, under two Representative Concentration Pathways (RCP4.5 and RCP8.5). All the models agree that the mean temperature will rise over this century, with the highest increases in the warm season. The total annual rainfall is not expected to significantly vary in the future although systematic changes are present in some months: a decrease in April and July and an increase in November. The daily temperature projections of the RCMs were used to identify potential variations in the characteristics of the heat waves; an increase of their frequency is expected over this century.

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Spatiotemporal Variations of Drought and Their Teleconnections with Large-Scale Climate Indices over the Poyang Lake Basin, China

Sustainability ◽

10.3390/su12093526 ◽

2020 ◽

Vol 12 (9) ◽

pp. 3526 ◽

Cited By ~ 2

Author(s):

Weilin Liu ◽

Shengnan Zhu ◽

Yipeng Huang ◽

Yifan Wan ◽

Bin Wu ◽

...

Keyword(s):

Water Resource Management ◽

Large Scale ◽

Poyang Lake ◽

Southern Oscillation ◽

Trend Test ◽

Climate Indices ◽

Lake Basin ◽

Spatiotemporal Variations ◽

Poyang Lake Basin ◽

Decadal Scale

The intensity and frequency of droughts in Poyang Lake Basin have been increasing due to global warming. To properly manage water resources and mitigate drought disasters, it is important to understand the long-term characteristics of drought and its possible link with large-scale climate indices. Based on the monthly meteorological data of 41 meteorological stations in Poyang Lake Basin from 1958 to 2017, the spatiotemporal variations of drought were investigated using the standardized precipitation evapotranspiration index (SPEI). Ensemble empirical mode decomposition (EEMD) methods and the modified Mann–Kendall (MMK) trend test were used to explore the spatiotemporal characteristics and trends of drought. Furthermore, to reveal possible links between drought variations and large-scale climate indices in Poyang Lake Basin, the relationships between SPEI and large-scale climate indices, such as North Atlantic Oscillation (NAO), El Niño–Southern Oscillation (ENSO), Arctic Oscillation (AO), Indian Ocean Dipole (IOD) and Pacific Decadal Oscillation (PDO) were examined using cross-wavelet transform. The results showed that the SPEI in Poyang Lake Basin exhibited relatively stable quasi-periodic oscillation, with approximate quasi-3-year and quasi-6-year periods at the inter-annual scale and quasi-15-year and quasi-30-year periods at the inter-decadal scale from 1958 to 2017. Moreover, the Poyang Lake Basin experienced an insignificantly wetter trend as a whole at the annual and seasonal scales during the period of 1958–2017, except for spring, which had a drought trend. The special characteristics of the trend variations were markedly different in the basin. The areas in which drought was most likely to occur were mainly located in the Poyang Lake region, northwest and south of the basin, respectively. Furthermore, relationships between the drought and six climate indices showed that the drought exhibited a significant temporal correlation with five climate indices at restricted intervals, except for IOD. The dominant influences of the large-scale climate indices on the drought evolutions shifted in the Poyang Lake Basin during 1958–2017, from the NAO, Niño 3.4, and the Southern Oscillation Index (SOI) before the late 1960s and early 1970s, to the AO and PDO during the 1980s, then to the NAO, AO and SOI after the early 2000s. The NAO, AO and SOI exerted a significant influence on the drought events in the basin. The results of this study will benefit regional water resource management, agriculture production, and ecosystem protection in the Poyang Lake Basin.

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Temporal Description of Annual Temperature and Rainfall in the Bawku Area of Ghana

Advances in Meteorology ◽

10.1155/2020/3402178 ◽

2020 ◽

Vol 2020 ◽

pp. 1-18 ◽

Cited By ~ 2

Author(s):

Yaw Asamoah ◽

Kow Ansah-Mensah

Keyword(s):

Temporal Variations ◽

Significant Rise ◽

The Other ◽

Annual Rainfall ◽

Trend Test ◽

Homogeneity Test ◽

Climate Data ◽

Other Hand ◽

Standardised Precipitation Index ◽

Most Significant Change

With varied implications, Ghana’s temperature and rainfall are projected to rise and decline, respectively. A study exposing specific areas of concern for appropriate responses in this regard is a welcome one. This study sought to describe the temporal variations in temperature and rainfall in the Bawku Area of Ghana. A forty-year (1976–2015) daily climate data was collected on three meteorological stations from the Ghana Meteorological Agency. Normality test, homogeneity test, Standardised Precipitation Index (SPI) analysis, Mann–Kendall trend test, and One-way post hoc ANOVA were performed using XLSTAT and DrinC. Over the period under study, the mean annual rainfall pattern was generally erratic, fluctuating between 669.8 mm and 1339.4.6 mm with an annual average of 935.3 mm. The long-term (40-year period) average temperature of the three stations, on the other hand, was 28.7°C, varying between 26.9°C and 29.9°C annually. Whereas the SPI value of 2006 was ≥2.0, indicating extremely wet year with 2.3% probability of recurring once every 50 years, 1988 was the hottest year with temperature anomaly value of 1.2°C, while coolest years were 1979 (−1.8°C) and 1976 (−1.0°C). The Mann–Kendall trend test showed a rise in rainfall in Binduri, Garu-Tempane, and Manga, yet none of the rainfall changes were statistically significant (P>0.05). Mean temperature on the other hand experienced a significant rise (P<0.05). With an R-square of 34.7%, the rise in temperature in Manga witnessed the most significant change in annual temperature changes. There were statistically significant (P<0.05) differences in the interdecadal temperature over the 40-year period. Generally, it can be stated that both temperature and rainfall vary in the study area with various degrees of disparities, but temperature assumes an upward trend at a faster rate. We therefore recommend that stakeholders resort to the construction of dams and boreholes to ensure regular availability of water for both domestic and agricultural uses.

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Climate Change Projection In Kashmir Valley (J&K)

Current World Environment ◽

10.12944/cwe.12.1.13 ◽

2017 ◽

Vol 12 (1) ◽

pp. 107-115 ◽

Cited By ~ 2

Author(s):

Saqib Parvaze ◽

Latief Ahmad ◽

Sabah Parvaze ◽

Raihana Kanth

Keyword(s):

21St Century ◽

Minimum Temperature ◽

Decision Support Tool ◽

Annual Precipitation ◽

Maximum Temperature ◽

Climatic Data ◽

Climate Data ◽

Kashmir Valley ◽

Support Tool ◽

Period Increase

The decision support tool viz. SDSM (Statistical Downscaling Model) was used to downscale climate data of future years for Kashmir province of Jammu & Kashmir state. The 21st century projected data for the A1B scenario was adjusted by using observed climatic data recorded during the period 1985-2015 for the region. The data from the same period was taken as the baseline for the analysis. This data was thereon analyzed for monthly, seasonal, cropping season and annual periods to enumerate the variation of maximum temperature, minimum temperature and precipitation in Kashmir valley of Jammu & Kashmir state in the 21st century. The modelled data obtained exhibited no significant change in maximum and minimum temperature for the period 2021-2050 but for the same period increase in annual precipitation was exhibited. For the period2051-2100, decreasing trend of annual temperature was exhibited whereas for annual precipitation, an increasing trend was exhibited.

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Trends of Rainfall and Temperature in Bangladesh: A Comparative Analysis of CMIP5 Results and Meteorological Station Data

The Dhaka University Journal of Earth and Environmental Sciences ◽

10.3329/dujees.v9i2.55085 ◽

2021 ◽

Vol 9 (2) ◽

pp. 9-18

Author(s):

Himel Bosu ◽

Towhida Rashid ◽

Abdul Mannan ◽

Javed Meandad

Keyword(s):

Spatial Distribution ◽

Comparative Analysis ◽

Coupled Model ◽

Meteorological Station ◽

Temperature Data ◽

Annual Rainfall ◽

Maximum Temperature ◽

Cmip5 Models ◽

Historical Period ◽

Environmental Sciences

The Coupled Model Inter-comparison Project phase 5 (CMIP5) dataset along with rainfall and temperature data, recorded at 34 stations of Bangladesh Meteorological Department (BMD), is analyzed to examine the recent changes in rainfall and temperature over Bangladesh during the period 1981-2019. In the historical period, all three CMIP5 models (MPI-ESM-LR, MPI-ESM-MR and NorESM1-M) underestimated the observed mean rainfall data collected from BMD, whereas for temperature the result is found to be nearly similar between model and observation. The result shows a trend of increasing mean maximum temperature of Bangladesh at a rate of 0.19°C and 0.26°C per decade and increasing mean minimum temperature at a rate of 0.18°C and 0.15°C per decade, for model and observation respectively. The study found a decreasing trend of annual rainfall in Bangladesh observed at a rate of 41.60 mm and 39.77 mm per decade, respectively, for model and observation. Spatial distribution shows an increase in annual rainfall in the northeastern part of Bangladesh. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 9(2), 2020, P 9-18

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